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1 HOW THE CARBURETTER WORKS

The carburetter proportions and atomises the right amount of petrol with the air that is drawn in by the engine because of the correct proportions of the jet sizes and the main choke bore. The float chamber maintains a constant level of fuel at the jets and cuts off the supply when the engine stops.

The throttle control from the handlebar controls the volume of mixture and therefore the power, and at all positions of throttle, the mixture is automatically correct. The opening of the throttle brings first into action the mixture supply from the pilot jet system of idling, then as it progressively opens via the pilot by-pass, the mixture is augmented from the main jet, the earlier stages of which action is is controlled by the needle in the needle jet. The pilot jet system is supplied by the pilot jet (30) which is detachable on removal of the float chamber. On certain other models no pilot jet is fitted but a pilot bush is inserted in the continuation of the of the pilot air adjusting screw passage. The main jet does not spray directly into the mixture chamber, but discharges through the needle jet into the primary air chamber, and goes from there as a rich petrol-air mixture through the primary air choke into the main air choke.

The carburretters usually have a separately operated mixture control called an air valve, for use when starting from cold, and until the engine is warm; this control partially blocks the passage of air through the main choke.

This design of carburetter offers perfectly simple and effective tuning facilities.

Far right drawing, #30 shows a vertically oriented threaded pilot jet. This is only encountered on the 1968 Concentrics. The Concentric bodies retain the vertical threads due to some two stroke applications requiring them still, All 4 stroke carbs were supplied with pressed in bush, see nearer right diagram. Premier versions of the MK1 Concentric have done away with the pressed in bushing and utilize a threaded brass/steel jet opposite of #34 “pilot air adjusting screw” near right drawing.

  1. Mixing Chamber Top

  1. Air Valve Spring

  1. Air Valve Spring

  1. Air Valve

  1. Float Needle

  1. Needle Seating

  1. Filter Gauze

  1. Banjo

  1. Banjo Bolt

  1. Cable Adjuster (Air)

  1. Cable Adjuster (Throttle)

  1. Cable Adjuster Locknuts

  1. Carburetter Body

  1. Throttle Valve Spring

  1. Jet Needle Clip

  1. Pilot By-pass

  1. Pilot Outlet

  1. Float Chamber Body

  1. Float

  1. Mixing Chamber Top Screws

  1. Throttle Valve

  1. Jet Needle

  1. Choke Tube

  1. Needle Jet

  1. Tickler

  1. Throttle Adjusting Screw

  1. Float Chamber Washer

  1. Jet Holder

  1. Main Jet

  1. Pilot Jet

  1. Pilot Jet Feed Passage

  1. Feed Passage From Pilot Jet

  1. Pilot Air Feed Passage

  1. Pilot Air Adjusting Screw


2 HINTS AND TIPS

STAR, FROM COLD: Turn on fuel supply, set ignition (if manually operated) for best slow running, depress tickler to flood float chamber, close air valve, open throttle slightly and start engine. When engine starts open air valve and close the throttle; if engine begins to falter, partially close the air valve until engine is warm, then set in fully open position,

STARTING, ENGINE HOT: Open throttle slightly and start engine. It should not normally be necessary to flood the float chamber or close air valve when starting a warm engine.

STARTING, GENERAL: Experience will show when it is necessary to flood the carburetter or use the air valve, and also the best setting of the throttle valve. If the carburetter has been over-flooded or strangled, which would result in a wet engine the over-rich starting mixture – fully open the throttle valve and air valve, give the engine several turns to clear the richness, then start again with air valve fully open and the throttle valve slightly open.

STARTING, SINGLE LEVER CARBURETTER. OPEN THE THROTTLE VERY SLIGHTLY FROM THE IDLING POSITION AND FLOOD THE CARBURETTER MORE OR LESS ACCORDING TO THE ENGINE BEING COLD OR HOT RESPECTIVELY.

CABLE CONTROL: See that there is a minimum of backlash when the controls are set back and that any movement of the handlebars does not cause the throttle to open; this is done by the adjusters on top of the carburetter, after releasing the adjuster locknuts. See that the throttle valve shuts down freely, then reset locknuts.

PETROL FEED: A filter Gauze is fitted at the inlet to the float chamber, to remove this gauze, unscrew the banjo bolt (9) the banjo and filter gauze can then be removed. Before replacement ensure that the filter gauze is both clean and undamaged and check fuel supply by momentarily turning fuel tap. Vertical loops in petro pipes must be avoided to prevent air locks. Float chamber flooding may be due to worn float needle but nearly all flooding and blockage of the filter gauze with new machines is due to impurities from the tank. Periodically clean out filter gauze and float chamber until trouble ceases or alternatively the tank may be drained and swilled out, etc.

FIXING THE CARBURETTER AND AIR LEAKS: Erratic slow running is often caused by air leaks, so verify there are none at the point of attachment to the cylinder or inlet pipe. A sealing ring is fitted into the attachment flange of the carburetter. Also in old machines look out for air leaks caused by warn throttle or worn inlet guide.

BANGING IN EXHAUST May be caused by too weak of a pilot mixture when the throttle is closed or nearly closed – also it may be caused by too rich a mixture and air leaks in the exhaust system. The reason either case is that the mixture has not fired in the cylinder and has fired in the hot silencer. If the banging happens when the throttle is fairly wide open the trouble will be ignition ignitions – not carburetion.

BAD PETROL CONSUMPTION Of a new machine, may be due to flooding caused by impurities from the petrol tank lodging on the float needle seat, and so prevents its valve from closing. Flooding may be caused by a worn float needle valve. Also bad petrol consumption will be apparent if the needle jet (24) has worn; it may be remedied or improved by lowering the needle in the throttle, but if it cannot be – then the only remedy is to get a new needle jet.

AIR FILTERS: These may affect the jet setting, so if one is fitted afterwards to the carburetter the main jet may have to be smaller. If the carburetter is set with an air filter and the engine is run without it, take care to not overheat the engine due to weak a mixture; testing with the air valve (Page 5), will indicate a larger main jet and higher needle position are required.

EFFECTS OF ALTITUDE ON CARBURETTER: Increased altitude tends to produce a rich mixture. The greater the altitude, the smaller main jet required. Carburetters ex-works are set suitable for altitudes 3,000 feet approximately. Carburetter used constantly at altitudes 3,000 to 6,000 feet should have a reduction in main jet size of 5%. and thereafter for every 3,000 feet in excess of 6,000 feet altitude further reductions of 4%, should be made.


3 RE-ASSEMBLING

When replacing the valve assembly, see that the jet needle goes into the holes in the choke tube, needle jet and main jet and that both the throttle and air valve spring locate correctly in the mixing chamber top.

When refitting the float, engage the float needle recess in the horseshoe section of the float and fit in the float chamber. Check that the needle jet (24) jet holder (28) and and the main jet (29) and fully tightened together before screwing assembly into the body.

 

HOW TO TRACE FAULTS

There are only two possible faults in carburation, either richness or weakness of mixture.

INDICATIONS OF:

RICHNESS

WEAKNESS

Black smoke in exhaust. Spitting back in carburetter.
Petrol spraying out of carburetter. Overheating.
Four stroke, eight-stroking. Acceleration poor.
Two stroke, four-stroking. Engine goes better it; Throttle is not wide open or Air Valve is partially closed
Heavy, lumpy running.
Spark plug sooty.

If Richness or weakness it present, check if caused by:

  1. Petrol feed – Check that jets and passages are clear, that filter gauze in float chamber banjo connection is not choked with foreign matter, and that there is ample flow of fuel. Check there is no flooding.
  2. Air leaks – At the connection to the engine or due to leaky inlet valve stems.
  3. Defective or worn parts – As a loose fitting throttle valve, worn needle jets loose jets.
  4. Air cleaner being choked up.
  5. An air cleaner having been removed

Removing the silencer or running with a straight through pipe required a richer setting.

Having verified the correctness of fuel feed and that there is no air leaks, check over ignition, valve operation and timing. Now at throttle position shown on page 7, Fig.5, test to see if mixture are rich or weak. This is done by partially closing the air valve, and if engine runs better weakness is indicated, but if engine runs worse richness is indicated.

TO REMEDY PROCEED AS FOLLOWS:

TO CURE RICHNESS TO CURE WEAKNESS
  1. Fit smaller main jet
  1. Fit larger main jet

  1. Screw out pilot air adjusting screw
  1. Screw pilot air adjusting screw in

  1. Fit a throttle with larger cutaway (page 6)
  1. Fit a throttle with smaller cutaway (page 6)

  1. Lower needle on or two grooves (page 6)
  1. Raise needle one or two grooves (page 6)

NOTE: It is not to cure a rich mixture at half throttle by fitting a smaller main jet because the main jet may be correct for full power at full throttle: the proper thing to go is to lower the needle.


4 PARTS TO TUNE UP

THROTTLE ADJUSTING SCREW (26). Set this screw to hold the throttle open sufficiently to keep the engine running when twist grip is off. As “O” ring is fitted to the screw to hold this adjustment by friction.

MAIN JET (29). The main jet controls the petrol supply when the throttle is more than three-quarters open, but at smaller throttle openings, although the supply of fuel goes through the main jet, the amount is diminished by the metering effect of the needle in the needle jet. Each jet is calibrated and numbered so that its exact discharge is know and two jets of the same number are alike.

NEVER REAM A JET OUT, GET ANOTHER OF THE RIGHT SIZE!

The bigger the number ther bigger the jet.

To remove the main jet, remove the float chamber, the main jet can then be unscrewed from the jet holder (28)

NEEDLE AND NEEDLE JET (22 and 24). The needle being taper either allows more or less petrol to pass through the needle jet as the throttle is opened or closed throughout the range, except when idling or nearly full throttle. The taper needle position in relation to the throttle valve can be set according to the mixture required by repositioning the jet needle clip in any of three positions thus raising or lowering it. Raising the needle richens the mixture and lowering it weakens the mixture at throttle openings from quarter to three quarters open ( see Fig 5. pag 7). The throttle needles are marked with a single groove around the top diameter for use on the 600 series carburetter, the 900 series carburetter needles are identified by three grooves around the top needle, throttle needles identified by two grooves are used on certain models for both series 600 and 900 carburetters.

THROTTLE VALVE CUT-AWAY. The atmospheric side of the throttle is cut away to influence the depression on the main fuel supply and thus gives a meaning of tuning between the pilot and needle jet range of throttle opening. The amount of cut-away is recorded by a number marked on the throttle valve, viz., 622/3 means throttle valve type 622 with a No.3 cut-away; larger cut-aways, say 4 and 5, wive weaker mixtures and 2 a richer mixture.

AIR VALVE (3) Is used only for starting and running when cold, and experimenting with, otherwise run it wide open.

TICKLER (25) A small plunger, spring loaded, fixed in the carburetter body. When pressed down on the float the needle valve is allowed to open and so “flooding” is achieved. Flooding temporarily enriches the mixture until the level of the petrol subsides to normal.

ALCOHOL FUELS. When using alcohol fuels, the following new components are necessary. A metallic banjo, preferably double feed if not already fitted, float chamber 622/051, banjo bolt washer 13/163, needle jet 622/100, jet needle 622/099 or 928/099 according to type of carburetter, filter gauze 376/093B and banjo washer 14/175. The main jet must be increased for straight alcohol by approximately 150%. The final setting must be a question of trial and error according to the nature of the fuel being used.

 

When using alcohol fuels it is advisable to error on the rich side to avoid engine overheating.


5 HOW TO TUNE UP

PHASE OF AMAL NEEDLE JET CARBURETTER

THROTTLE OPENINGS

NOTE. The carburetter is automatic throughout the throttle range – the air valve should always be wide open except when used for starting or until the engine has warmed up. We assume normal petrols are used.

READ REMARKS ON SECTION 3 and 4 For each tuning device, and get the motor going perfectly on a quiet road with a slight up gradient so that on test the engine is pulling.

TUNE UP IN THE FOLLOWING ORDER

1st MAIN JET  With throttle position 1 (fig 5). If at full throttle the engine runs “heavily” the main jet is too large. If at full throttle by slightly closing the throttle or air valve the engine seems to have better power, the main jet is too small. With a correct sized main jet the engine at full throttle should run evenly and regularly with maximum power. If testing for speed work, ensure the main jet size is sufficient for the mixture to be rich enough to keep the engine cool, and to verify this, examine the spark plug after taking the first run, declutching and stopping the engine quickly. If the plug body at its end has a cool appearance the mixture is correct: if sooty, the mixture is rich : if however there are signs of intense heat, the mixture is too weak and a larger main jet is necessary.

2nd PILOT JET (fig 5) with throttle in position 2 and 5. With engine idling too fast, with the twist grip shut off and the throttle shut down on to the throttle adjusting screw, and ignition set for best slow running: (1) Screw out throttle adjusting screw runs slower and begins to falter, then screw pilot air adjusting screw in or out to make the engine run regularly and faster. (2) Now gently lower the throttle adjusting screw until the engine runs slower and just begins to falter, adjust the pilot air adjusting screw to get best slow running: if this 2nd adjustment makes the engine run too fast, go over the job again a third time. Both the throttle adjusting screw and pilot air screw have an “o” ring fitted to hold adjustment by friction.

3rd THROTTLE CUT-AWAY With throttle in position 4 (fig 5). ifm as you take off from idling position, there is objectionable spitting from the carburetter, slightly richen the pilot mixture by screwing in the air screw sufficiently, but if this is not effective, screw it back again, and fit a throttle with a smaller cut-away. If the engine jerks under load at this position and there is no spitting, either the jet needle is much too high, or a larger throttle cut-away is required to care richness.

4th NEEDLE With throttle in position 4 (fig 5). The needle controls a wide range of throttle opening and also the acceleration. Try the needle in the lower position, with the clip in the groove at the top; if acceleration is poor and with air valve partially closed the results are better, raise the needle by two grooves; if very much better try lowering the needle by one groove and leave it where it is best. If mixture is still too rich with clip in groove No 1. nearest the top, the needle jet might need replacement due to wear. If the needle itself has had several years of use replace its also.

5th FINALLY Go over the idling again for final touches.

 

TUNING TWIN ENGINES WITH

TWIN CARBURETTOR

WHERE EACH CYLINDER HAS ITS OWN CARBURETTER

First of all , slacken the throttle stop screws and put the twist grip into the shut off position to allow the throttles to shut off; there should be a slight backlash in the cables which backlash can be obtained , if necessary, by screwing in the cables adjusting screws on top of the carburetter after releasing lock nuts. Then, with the handlebar in the normal position , and with the throttles closed, adjust the cable adjusting screws so that on the slightest opening twist of the grip, both throttles open simultaneously, then reset the lock nuts.

To set the carburetters, follow the procedure as given in section 5, and bear in mind these “Hints”, which may be useful: main jet sizes are of course selected  by checking the effect of the mixture  on the spark plugs after taking a run at full throttle over a straight piece of roads; the smallest pair of jets that give the best maximum speed are usually correct provided that the plugs do not show any signs of excessive heat. It might be that for really critical tuning, one carburetter might require a different jet size from the other.

For slow running, set the twist grip to make the engine run slowly but just faster than a “tick-over”: then gently screw in in the throttle stops to just hold the throttles in that position and return the twist grip into the shut position, leaving the engine running on the throttle stops.

The next thing to do is set each carburetter  according to paragraph 2, on section 5, to obtain the idling by screwing down the throttle stop screws and adjusting the pilot air screws accordingly.

Regarding the setting of the pilot, a fairly satisfactory method is to detach on spark plug lead, and set the pilot air adjusting screw on the other cylinder as a single unit, and then reversing the process to the other cylinder. It may be found that when both leads are connected to the spark plugs, the engine runs slightly quicker than desirable, in which case, a slight readjustment of the throttle stop screws will put this right. It is essential that the speed of idling on both cylinder is approximately the same, as either make or mar the smoothness of the get-away on the initial opening of the throttle.

It is essential with twin carburetters that the throttle slides are a good fit in the bodies, and also that there is no suspicion of air leaks at either of the flange attachments to the cylinder.

Regarding lower end throttle range, which is always the more difficult to set, one can only take excessive pains to make a quite sure that the control cables are perfectly adjusted, without any excessive back lash or difference in the amount of back lash between one carburetter and another; otherwise one throttle will be out of phase with the other, and so resulting in lumpy running.

To check the opening of the throttle simultaneously, shut the twist grip back so that the throttles are resting on the throttle stop screws in their final position of adjustment; then insert the finger into the air intakes and press them on the throttles and with the other hand, gently open by the twist grip and feel that the throttles lift off the stops at the same time.[/vc_column_text]

Triumph Singles and Twins 100cc-350cc

Models

Year Range

Carb Spec Number

Internal Bore

Main Jet

Pilot Jet

Needle Jet

Needle Position

Throttle Valve

Float Chamber

100cc

Tina Scooter

1961-62

32/2

23/32″

32/023-105

4/042-25

32/031-105

3

32/0462

Included

Tina Scooter

1962-64

32/15

23/32″

32/023-105

4/042-25

32/031-105

3

32/0462

Included

T10 Scooter

1965-66

32/18

23/32″

32/023-95

4/042-15

32/031-105

2

32/0224

Included

150cc

Terrier

1953

332/1

3/4″

4/042-120

332/016

332/002-086

2

332/00544

3EB

Terrier

1954-56

332/2

11/16″

4/042-90

376/076-20

332/002-086

3

332/00544

3EB

Terrier

1958

3332/6

11/16″

4/042-90

376/076-20

332/002-086

3

332/00544

3EB

T.S.I. Tigress Scooter

1960

363/9

13/16″

363/044-130

376/076-15

363/018-106

5

363/09235

200cc

T.S.I. Tigress Scooter

1961

363/11

13/16″

363/044-130

376/076-15

363/018-106

5

363/09235

T20 Tiger Cub

1954

332/3

3/4″

4/042-100

376/076-20

332/002-086

3

332/00544

3EB

T20 Tiger Cub

1955-57

332/3

3/4″

4/042-100

376/076-20

332/002-086

3

332/00544

3EB

T20 Tiger Cub

1957

332/3

3/4″

4/042-100

376/076-20

332/002-086

3

332/00544

3EB

T20J Tiger Cub

1957-58

332/3

3/4″

4/042-100

376/076-20

332/002-086

3

332/00544

3EB

T20 Tiger Cub (Export)

1959

332/7

13/16″

4/042-140

376/076-15

332/002-86

3

332/00544

3EB

T20S Tiger Cub Scrambler

1959-60

376/217

15/16″

376/100-140

376/076-20

376/072-106

3

376/060-3

14/620 (remote

T20T Trials, T20 Tiger Cub

1960-61

3765/44

25/32″

376/100-100

376/076-25

376/072-105

3

375/060-3.5

T20S & T20SL Scrambler

1961-67

376/272

15/16″

376/100-1540

376/076-20

376/072-106

3

376/060-2.5

T20 Tiger Cub

1962-66

32/1

11/16″

32/023-85

4/042-15

32/033-104

2

32/0462

Included

T20 SM Sports

1965-67

376/314

15/16″

376/100-140

376/076-15

376/072-105

3

376/060-3.5

T20 Tiger Cub (Export)

1962-65

32/3

11/16″

32/023-110

4/042-15

32/033-103

2

32/0462

Included

T20SS, SH, Scrambler

1962-66

376/272

15/16″

376/100-140

376/076-20

376/072-106

3

376/060-2.5

T20 Trials and WD

1963-66

375/44

25/32″

376/100-100

376/076-20

376/072-105

3

375/060-3.5

T20B Bantom Cub

1966

375/61

25/32″

376/100-90

376/076-25

376/072-105T

3

375/060-3.5

T20 Super Cub

1967

375/61

25/32″

376/100-90

376/076-25

376/072-105T

3

375/060-3.5

T20 French Army

1973

R622/10

22mm

376/100-120

Bush

622/079-105

2

622/060-3.5

T20B Bantom Cub

1969

R622/3

22mm

376/100-120

Bush

622/079-105

2

622/060-3

T20B Bantom Cub

1970

R622/5

22mm

376/100-120

Bush

622/079-105

2

622/060-3

250cc

TR25W Trophy

1969-70

R928/20

28mm

376/100-200

Bush

622/122-106

1

928/060-3.5

TR25SS Trailblazer

1971-72

R928/20

28mm

376/100-200

Bush

622/122-106

1

928/060-3.5

350cc

3HW (Ex W.D.)

1940-45

276AD/1J

1″

4/042-150

4/061-107

2

6/052-4

1J (15)

Tiger “85”

1946-49

275AD/1A

7/8″

4/042-120

4/061-107

3

5/052-4

1A

3T De-Luxe

1946-48

275AD/1A

7/8″

4/042-120

4/061-107

3

5/052-4

1A

3T De-Luxe

1949-50

275AQ/1A

7/8″

4/042-120

4/061-107

3

5/052-4

1A

3T De-Luxe

1951-52

275BK/1A

7/8″

4/042-120

4/061-107

3

5/052-4

1A

3T (A.A.)

1953

274AB/1AT

21/32″

4/042-75

4/061-106

1

4/052-4

1AT (7)

T21 Twin

1957

375/23

13/16″

376/100-110

376/076-25

376/072-105

3

375/060-3.5

T21 Twin

1957-61

375/62

25/32″

376/100-100

376/076-25

376/072-105

3

375/060-3.5

T90

1963-67

376/300

15/16″

376/100-180

376/076-20

376/072-106

3

376/060-3

T90

1958

R626/2

24mm

376/100-140

Bush

622/122-106

2

622/060-3.5

P30 Bandit (pair)

1971

R626/56

26mm

376/100-140

Bush

622/122-106

1

622/060-3

L626/56

26mm

376/100-140

Bush

622/122-106

1

622/060-3

Triumph 500 Twins

Models

Year Range

Carb Spec Number

Internal Bore

Main Jet

Pilot Jet

Needle Jet

Needle Position

Throttle Valve

Float Chamber

5T Speed Twin

1946-48

276AX/1AT

15/16″

4/042-140

4/061-107

3

6/052-3.5

1AT (7)

5T Speed Twin

1946-48

276DK/1AT

15/16″

4/042-140

4/061-107

3

6/052-3.5

1AT (7)

5T Speed Twin

1951-54

276FE/1AT

15/16″

4/042-140

4/061-107

3

6/052-3.5

1AT (7)

5T Speed Twin

1955-58

376/25

15/16″

376/100-200

376/076-30

376/072-106

4

376/060-3.5

5TA

1958-65

375/35

7/8″

376/100-160

376/076-25

376/072-105

3

375/060-3.5

Tiger “100”

1946-48

276BN/1AT

1″

4/042-160

4/061-107

3

6/052-3.5

1AT (7)

Tiger “100”

1949-50

276DL/1AT

1″

4/042-150

4/061-107

2

6/052-3.5

1AT (7)

Tiger “100”

1951-53

276FH/1AT

1″

4/042-150

4/061-107

2

6/052-3.5

1AT (7)

Tiger “100”

1954

276GE/2EK

1″

4/042-150

4/061-107

2

6/052-3.5

2EK

T100 Racing

1949-50

(RH) 76AH

1″

4/042-150

4/061-107

3

6/052-4

14/538

(LH) 76AJ

1″

4/042-150

4/061-107

3

6/052-4

14/538

Tiger 100R (Race Kit)

1951-52

(RH) 76AO

1″

4/042-190

4/061-109

3

6/052-4

14/538

(LH) 76AN

1″

4/042-190

4/061-109

3

6/052-4

14/538

T100C

1953

(RH) 76AS

1″

4/042-150

4/061-107

2

6/052-4

14/538

(LH) 76AR

1″

4/042-150

4/061-107

2

6/052-4

14/538

Tiger 100C for Dytona, Tiger 100RS

1955-57

T15GP

1″

376/100-250

316/065-107

1

316/104-6

302/11

1″

376/100-250

316/065-107

1

316/104-6

TR5 Trophy

1950

276EK/1A

15/16″

4/042-140

4/061-107

2

6/052-3.5

1A

TR5 Trophy

1951-53

276FF/1AT

1″

4/042-150

4/061-107

2

6/052-3.5

1AT (7)

TR5

1954

276GH

1″

4/042-150

4/061-107

2

6/052-3.5

302/13

Tiger 100, TR5, Trophy & Trials TR5

1955-61

376/35

15/16″

376/100-220

376/076-25

376/072-106

4

376/060-3.5

Tiger 100 (Export) (use pair w/ Delta Head)

1957-60

376/77

1″

376/100-200

376/076-25

376/072-106

3

376/060-3.5

Tiger 100 Twin T100RR

1957-59

T15GP

1″

376/100-250

316/065-107

2

316/1046

302/19

1″

376/100-250

316/065-107

2

316/1046

(Remote)

TR5A/R/C Compition Twin

1961

376/273

1″

376/100-190

376/076-25

376/18-106

3

376/060-3.5

T100SS, T100S, T100R, T100C, and T100CR

1961-67

376/273

1″

376/100-190

376/076-25

376/072-106

3

376/060-3.5

Tiger T100S T100C

1968-69

R626/8

26mm

376/100-180

Bush

622/122-106

2

622/060-4

T100, T100C

1970

R626/25

26mm

376/100-170

Bush

622/122-106

2

622/060-4

T100, T100C

1971

R626/32

26mm

376/100-170

Bush

622/122-106

2

622/060-4

T100

1972

R626/52

26mm

376/100-170

Bush

622/122-106

2

622/060-4

T100T, T100R Daytona

1967

376/324

1 1/16″

376/100-200

376/076-25

376/072-106

3

376/060-3.5

376/325

1 1/16″

376/100-200

376/076-25

376/072-106

3

376/060-3.5

T100T, T100R Daytona

1968-69

R626/10

26mm

376/100-160

Bush

622/122-106

2

622/060-3

L626/9

26mm

376/100-160

Bush

622/122-106

2

622/060-3

T100T Daytona

1970

R626/26

26mm

376/100-150

Bush

622/122-106

1

622/060-3

L626/27

26mm

376/100-150

Bush

622/122-106

1

622/060-3

T100T, T100R Daytona (pair)

1971-72

R626/53

26mm

376/100-150

Bush

622/122-106

1

622/060-3

L626/54

26mm

376/100-150

Bush

622/122-106

1

622/060-3

T100SS Daytona (pair)

1973-74

R626/64

26mm

376/100-150

Bush

622/122-106

1

622/060-3.5

L626/65

26mm

376/100-150

Bush

622/122-106

1

622/060-3.5

TR5T Trophy Tail, Adventurer

1973

R928/21

28mm

376/100-180

Bush

622/122-1060

2

928/060-3

TR5T Trophy Tail, Adventurer

1974

R928/21

28mm

376/100-210

Bush

622/122-1060

2

928/060-3

Triumph 650 Twins

Models

Year Range

Carb Spec Number

Internal Bore

Main Jet

Pilot Jet

Needle Jet

Needle Position

Throttle Valve

Float Chamber

6T thunderbird

1950

276EA/1AT

1″

4/042-170

4/061-107

2

6/052-3.5

1AT (7)

6T thunderbird

1950

276EA/1AT

1″

4/042-170

4/061-107

2

6/052-3.5

1AT (7)

6T thunderbird

1951-53

276EW/1AT

1 1/16″

4/042-140

4/061-107

2

6/052-3.5

1AT (7)

6T thunderbird

1952-58

MC2 (SUS

1 1/4″

AUC 8182

TR6 & 6T Thunderbird (Export)

1955-58

376/42

1 1/16″

376/100-270

376/076-25

376/072-106

4

376/060-3.5

6T Thunderbird (Home)

1959

376/42

1 1/16″

376/100-270

376/076-25

376/072-106

4

376/060-3.5

6T thunderbird (Export)

1959-60

376/245

1 1/16″

376/100-270

376/076-25

376/072-106

4

376/060-3.5

6T Thunderbird (Home)

1959-60

376/246

1 1/16″

376/100-270

376/076-25

376/072-106

4

376/060-3.5

6T thunderbird

1960-61

376/260

1 1/16″

376/100-270

376/076-25

376/072-106

4

376/060-3.5

6T thunderbird (Export)

1960-61

376/256

1 1/16″

376/100-270

376/076-25

376/072-106

4

376/060-3.5

6T thunderbird

1962

376/285

1 1/16″

376/100-220

376/076-25

376/072-106

4

376/060-4

6T thunderbird

1963-66

376/303

1 1/16″

376/100-220

376/076-25

376/072-106

4

376/060-4

6T Thunderbird (USA)

1964-65

376/309

1 1/16″

376/100-270

376/076-25

376/072-106

4

376/060-4

Tiger 110

1954

289X

1 1/8″

4/042-200

29/076-107

3

29/0624

302/13

Tiger 110, TR6A, B, C.

1955-61

376/40

1 1/16″

376/100-250

376/076-25

376/072-106

3

376/060-3.5

Tiger 110

1960

376/244

1 1/16″

376/100-250

376/076-25

376/072-106

4

376/060-3.5

Tiger 110

1960-61

376/255

1 1/16″

376/100-250

376/076-25

376/072-106

4

376/060-3.5

TR6 S/S

1962-63

376/40

1 1/16″

376/100-250

376/076-25

376/072-106

3

376/060-3.5

TR6 (inc. Police Model)

1964-66

389/97

1 1/8″

376/100-310

376/076-25

376/072-106T

1

389/060-3.5

Metropolitan Policem MK 111

1964-66

389/97

1 1/8″

376/100-310

376/076-25

376/072-106T

2

389/060-3.5

TR6 Trophy

1967

389/239

1 3/16″

376/100-330

376/076-25

376/072-106T

2

389/060-4

TR6, TR6R, TR6C

1968-70

R930/23

30mm

376/100-230

Bush

622/122-106

2

928/060-3.5

TR6, TR6R, TR6C

1970

R930/45

30mm

376/100-230

Bush

622/122-106

2

928/060-3.5

TR6 Police

1970

R930/65

30mm

376/100-210

Bush

622/122-106

2

928/060-3.5

TR6R, TR6C

1971-72

R930/60

30mm

376/100-230

Bush

622/122-106

2

928/060-3.5

TR6RV, TR6C

1973-74

R930/86

30mm

376/100-230

Bush

622/122-106

2

928/060-3.5

Bonneville T120 (pair)

1959

376/204

1 1/16″

376/100-250

376/076-25

376/072-106

2

376/060-3.5

14/617

Bonneville T120 (pair)

1959

376/233

1 1/16″

376/100-250

376/076-25

376/072-106

2

376/060-3.5

Bonneville T120, TR7A (USA) Tr7B (Scrambler USA)

1960

389/51

1 3/16″

376/100-310

376/076-30

376/072-106

3

389/060-3

Bonneville T120, T120C. (pair)

1960-63

376/257

1 1/16″

376/100-240

376/076-25

376/072-106

2

376/060-3.5

T120C, T120RS (Johnson Motors) T120 T.T. (Triumph Corp.)

1963-67 &1965-67

389/95

1 3/16″

376/100-330

376/076-25

376/072-106

2

389/060-4

T120R (U.S.A.)

1966

389/203

1 1/8″

376/100-260

376/076-20

376/072-106

3

389/060-3

T120 (pair)

1964/67

389/203

1 1/8″

376/100-260

376/076-20

376/072-106

3

389/060-3

T120R Johnson Motors

1963

376/302

1 1/16″

376/100-240

376/076-25

376/072-106

2

376/060-3.5

T120, T120R

1967-69

R930/9

30mm

376/100-190

Bush

622/122-106

2

928/060-3

L930/10

30mm

376/100-190

Bush

622/122-106

2

928/060-3

T120

1970

R930/43

30mm

376/100-190

Bush

622/122-106

2

928/060-3

L930/44

30mm

376/100-190

Bush

622/122-106

2

928/060-3

T120, T120R

1971-72

R930/66

30mm

376/100-180

Bush

622/122-106

1

928/060-3

L930/67

30mm

376/100-180

Bush

622/122-106

1

928/060-3

T120R T120V

1973-74

R930/84

30mm

376/100-180

Bush

622/122-106

1

928/060-3

L930/85

30mm

376/100-180

Bush

622/122-106

1

928/060-3

Triumph 750 Twins

Models

Year Range

Carb Spec Number

Internal Bore

Main Jet

Pilot Jet

Needle Jet

Needle Position

Throttle Valve

Float Chamber

T140V

1973

R930/87

30mm

376/100-190

Bush

622/122-106

1

928/060-3

L930/88

30mm

376/100-190

Bush

622/122-106

1

928/060-3

T140V

1974-78

R930/92

30mm

376/100-190

Bush

622/122-106

1

928/060-3

L930/93

30mm

376/100-190

Bush

622/122-106

1

928/060-3

T140D, T140E

1979-83

R2930/2

30mm

376/100-200

124/026-25

2928/031-105

2

2928/060-3

L2930/1

30mm

376/100-200

124/026-25

2928/031-105

2

2928/060-3

T140D, T140E

1981-83

R2930/8

30mm

376/100-200

124/026-20

2928/031-105

2

2928/060-3

L2930/9

30mm

376/100-200

124/026-20

2928/031-105

2

2928/060-3

Harris Bonneville

1985-87

R930/111

30mm

376/100-200

124/026-20

622/122-106

2

928/1053

L930/112

30mm

376/100-200

124/026-20

622/122-106

2

928/1053

TSS, TS8

1982

R2934/7

34mm

376/100-230

124/026-20

2928/122-106

2

2928/060-3.5

L2934/8

34mm

376/100-230

124/026-20

2928/122-106

2

2928/060-3.5

TR65SS, TR7T

1981-82

R930/108

30mm

376/100-240

Bush

622/122-106

1

928/060-3

TR65T

1981-82

R930/109

30mm

376/100-240

Bush

622/122-106

1

928/060-3

TR7RV

1973

R930/89

30mm

376/100-270

Bush

622/122-106

1

928/060-3

TR7V, TR7RV

1974-83

R930/94

30mm

376/100-270

Bush

622/122-106

1

928/060-3

Harris TR7

1985-87

R1930/94

30mm

376/100-270

124/026-25

622/122-106

1

928/1053

Triumph 750 Triples

Models

Year Range

Carb Spec Number

Internal Bore

Main Jet

Pilot Jet

Needle Jet

Needle Position

Throttle Valve

Float Chamber

T150 Trident

1959-70

R626/14, R626/16

27mm

376/100-150

Bush

622/122-106

2

622/060-3

L626/15

27mm

376/100-150

Bush

622/122-106

2

622/060-3

T150R Trident

1971

R626/47, R626/49.

27mm

376/100-150

Bush

622/122-106

2

622/060-3.5

L626/48

27mm

376/100-150

Bush

622/122-106

2

622/060-3.5

T150R Trident

1972

R626/61, R626/63

27mm

376/100-150

Bush

622/122-106

2

622/060-3.5

L626/62

27mm

376/100-150

Bush

622/122-106

2

622/060-3.5

T150V Trident

1973-74

R626/66, R626/68

27mm

376/100-150

Bush

622/122-106

2

622/060-3.5

L626/67

27mm

376/100-150

Bush

622/122-106

2

622/060-3.5

T150 Hurricane

1973

R626/69, R626/71

27mm

376/100-150

Bush

622/122-106

2

622/060-3.5

L626/70

27mm

376/100-150

Bush

622/122-106

2

622/060-3.5

T160 Trident

1975-76

R626/76

27mm

376/100-150

Bush

622/122-106

2

622/060-4

L626/77

27mm

376/100-150

Bush

622/122-106

2

622/060-4

Models Year Range Carb Spec Number Internal Bore Main Jet Pilot Jet Needle Jet Needle Position Throttle Valve Float Chamber
A Series 500-750cc
A10 Super Rocket & Spitfire Scrambler (U.S.A.) 1962-63 389/47 1 5/32” 376/100-290 376/076-25 376/072-106 2 389/060-3
A10 Super Rocket & Rocket Gold Star 1963 389/94 1 5/32” 376/100-310 376/076-25 376/072-106 2 389/060-3
A50 Twin 1961 376/282 1” 376/100-250 376/076-25 376/072-106 3 376/060-3.5
A50 Star (Home) 1962-65 376/282 1” 376/100-250 376/076-25 376/072-106 3 376/060-3.5
A50 Cyclone 19464-65 376/316 1 1/16” 376/100-170 376/076-25 376/072-106 2 376/060-3.5
A50 Cyclone (U.S.A.) 1964-65 376/310 1 1/16” 376/100-170 376/076-25 376/072-106 2 376/060-3.5
A50 Wasp 1966 389/227 1 1/18” 376/100-200 376/076-25 376/072-106 2 389/060-3.5
689/227 1 1/18” 376/100-200 376/076-25 376/072-106 2 689/060-3.5
A50 Wasp 1966 389/230 1 1/18” 376/100-190 376/076-25 376/072-106 2 389/060-3.5
689/230 1 1/18” 376/100-190 376/076-25 376/072-106 2 689/060-3.5
A50 Royal Star 1966-67 376/321 1” 376/100-260 376/076-25 376/072-106 3 376/060-3.5
A50 Royal Star (U.S.A.) 1966-67 376/319 1” 376/100-260 376/076-25 376/072-106 3 376/060-3.5
A50 Royal Star 1968 R626/7 26mm 376/100-200 124/026-25 622/122-106 2 622/060-3.5
A50 Royal Star 1969-70 R626/19 26mm 376/100-200 Bush 622/122-106 2 622/060-3.5
A65 Star (U.S.A.) 1962-63 389/70 1 1/8” 376/100-310 376/076-25 376/072-107 2 389/060-3
A65 Star (Home) 1962-65 389/67 1 1/8” 376/100-300 376/076-25 376/072-106 3 389/060-3.5
A65 Rocket (Home) 1963-65 389/201 1 1/8” 376/100-300 376/076-25 376/072-106 3 389/060-3.5
A65 Rocket (U.S.A.) 1964-65 389/202 1 1/8” 376/100-320 376/076-25 376/072-106 3 389/060-3.5
A65L Lightning Rocket 1964-65 389/206 1 1/8” 376/100-220 376/076-25 376/072-106 3 389/060-3.5
389/206 1 1/8” 376/100-220 376/076-25 376/072-106 3 389/060-3.5
A65 Mk11 Spitfire 1966 T10GP2 1 5/32” 376/100-260 376/076-25 316/065-107 2 316/01055 510/1
T10GP2 1 5/32” 376/100-260 376/076-25 316/065-107 2 316/01055 510/1
A65 Lightning & Hornet 1966 389/229 1 5/32” 376/100-270 376/076-25 376/072-106 4 389/060-3
689/229 1 5/32” 376/100-270 376/076-25 376/072-106 4 689/060-3
A65 Lightning & Hornet 1966-67 389/228 1 5/32” 376/100-270 376/076-25 376/072-106 4 389/060-3
689/228 1 5/32” 376/100-270 376/076-25 376/072-106 4 689/060-3
A65 Thunderbolt 1966-67 389/233 1 1/8” 376/100-300 376/076-25 376/072-106 3 389/060-3.5
A65 Thunderbolt (U.S.A.) 1966-67 389/234 1 1/8” 376/100-310 376/076-25 376/072-106 3 389/060-3.5
A65 Mk III Spitfire 1967-68 R932/1 32mm 376/100-190 124/026-20 622/122-107 2 928/060-3
L932/2 32mm 376/100-190 124/026-20 622/122-107 2 928/060-3
A65 Thunderbolt 1967 389/233 1 1/8” 376/100-300 376/076-25 376/072-106 3 389/060-3.5
A65 Thunderbolt 1968 R928/2 28mm 376/100-230 124/026-20 622/122-106 1 928/060-3.5
A65L Lightning & Hornet 1968 R930/21 30mm 376/100-190 124/026-20 622/122-106 3 928/060-2.5
L930/22 30mm 376/100-190 124/026-20 622/122-106 3 928/060-2.5
A65T Thunderbolt 1969-70 R928/6 28mm 376/100-230 Bush 622/122-106 1 928/060-3.5
A65 Lightning 1969-70 R930/34 30mm 376/100-180 Bush 622/122-106 1 928/060-3
L930/35 30mm 376/100-180 Bush 622/122-106 1 928/060-3
A65SS Firebird Scrambler 1969-70 R930/34 30mm 376/100-180 Bush 622/122-106 1 928/060-3
L930/35 30mm 376/100-180 Bush 622/122-106 1 928/060-3
A65SF Firebird Scrambler 1969-70 R930/34 30mm 376/100-180 Bush 622/122-106 1 928/060-3
L930/35 30mm 376/100-180 Bush 622/122-106 1 928/060-3
A65SS Firebird Scrambler 1971 R930/72 30mm 376/100-220 Bush 622/122-106 1 928/060-3
L930/73 30mm 376/100-220 Bush 622/122-106 1 928/060-3
A65SF Firebird Scrambler 1971 R930/72 30mm 376/100-220 Bush 622/122-106 1 928/060-3
L930/73 30mm 376/100-220 Bush 622/122-106 1 928/060-3
A64 Lightning 1971-72 R930/70 30mm 376/100-200 Bush 622/122-106 1 928/060-3
L930/71 30mm 376/100-200 Bush 622/122-106 1 928/060-3
A65T Thunderbolt 1971-72 R928/17 28mm 376/100-230 Bush 622/122-106 1 928/060-3.5
A70 Lightning 1971-72 R930/78 30mm 376/100-250 Bush 622/122-106 1 928/060-3
L930/79 30mm 376/100-250 Bush 622/122-106 1 928/060-3
A75R Rocket 3 1969-70 R626/14 27mm 376/100-150 Bush 622/122-106 2 622/060-3
L626/15 27mm 376/100-150 Bush 622/122-106 2 622/060-3
R626/16 27mm 376/100-150 Bush 622/122-106 2 622/060-3
A75R Rocket 3 1971-72 R626/61 27mm 376/100-150 Bush 622/122-106 2 622/060-3.5
L626/62 27mm 376/100-150 Bush 622/122-106 2 622/060-3.5
R626/63 27mm 376/100-150 Bush 622/122-106 2 622/060-3.5
A75R Rocket 3 1973 R626/66 27mm 376/100-150 Bush 622/122-106 2 622/060-3.5
L626/67 27mm 376/100-150 Bush 622/122-106 2 622/060-3.5
R626/68 27mm 376/100-150 Bush 622/122-106 2 622/060-3.5
B Series Singles 250-500cc
B29 1940-45 76P/1BB 1” 4/042-160 4/061-106 3 6/0524 1BB (3° & 7°)
B30 1940-45 276C/1B 1” 4/042-170 4/061-106 2 6/0524 1B
B31 1946-48 276AW/1BB 1” 4/042-150 4/061-106 3 6/0524 1BB (3° & 7°)
B31 1949-54 276DR/1AT 1” 4/042-150 4/061-106 3 6/0524 1AT (7°)
B31 (Home) 1955-56 376/2 1” 376/100-260 376/076-30 376/072-106 2 376/060-3.5
B31 Export (With Air Filter) 1955-60 376/3 1” 376/100-200 376/073-30 376/072-106 2 376/060-3.5
B31 (Home) 1957-59 376/81 1” 376/100-260 376/076-30 376/072-106 2 376/060-3.5
B31 (Export) 1957-59 376/82 1” 376/100-200 376/076-30 376/072-106 2 376/060-3.5
B32 1946-48 276AW/1BB 1” 4/042-150 4/061-106 3 6/0524 1BB (3° & 7°)
B32 1949-54 276DR/1AT 1” 4/042-150 4/061-106 3 6/0524 1AT (7°)
B32 Competition Scrambler 1955-57 376/43 1 1/16” 376/100-260 376/076-25 376/072-106 3 376/060-4
B33 1947-54 289G/1AT 1 1/8” 4/042-200 29/076-106 3 29/0624 1AT (7°)
B33 (Swedish) 1953 289V/1AT 1 1/8” 4/042-190 29/076-106 2 29/0623 1AT (7°)
B33 (Home) 1955-57 376/10 1 1/16” 376/100-260 376/076-25 376/072-106 3 376/060-3.5
B33 (Export With Air Filter) 1955-57 376/9 1 1/16” 376/100-210 376/076-25 376/072-106 3 376/060-3.5
B33 (Export) 1957-59 376/84 1 1/16” 376/100-210 376/076-25 376/072-106 3 376/060-3.5
B33 (Home) 1957-60 376/85 1 1/16” 376/100-260 376/076-25 376/072-106 3 376/060-3.5
B33 (Export) 1959-60 376/211 1 1/16” 376/100-210 376/076-25 376/072-106 3 376/060-3.5
B33 (Export) 1960 376/250 1 1/16” 376/100-210 376/076-25 376/072-106 3 376/060-3.5
B33 (Home) 1960 376/241 1 1/16” 376/100-260 376/076-25 376/072-106 3 376/060-3.5
B34 1949-54 289G/1AT 1 1/8” 4/042-200 29/076-106 3 29/0624 1AT (7°)
B34 (Swedish) 1953 289V/1AT 1 1/8” 4/042-190 29/076-106 2 29/0623 1AT (7°)
B34 Competition 1955-58 389/8 1 1/8” 376/100-240 376/076-25 376/072-106 2 389/060-3
B25 Starfire 1968-70 R928/8 28mm 376/100-260 124/026-25 622/122-106 2 928/060-3
B25 Starfire 1969 R928/5 28mm 376/100-180 124/026-25 622/122-106 2 928/060-3
B25SS Gold Star, B25T Victor 1971-72 R928/20 28mm 376/100-200 Bush 622/122-106 1 928/060-3.5
B40 (U.S.A.) 1961 389/78 1 1/8” 376/100-160 376/076-30 376/072-106 3 389/060-3.5
B40 MOD 1960-61 376/253 1 1/16” 376/100-190 376/076-20 376/072-106 3 376/060-3
B40 1962 376/253 1 1/16” 376/100-190 376/076-20 376/072-105 3 376/060-3
B40 (U.S.A.) 1962-63 389/78 1 1/8” 376/100-160 376/076-30 376/072-106 3 389/060-3.5
B40, SS90 1962-65 389/83 1 1/8” 376/100-200 376/076-30 376/072-106 3 389/060-3.5
B40 (Home) 1962-66 376/28 1 1/16” 376/100-190 376/076-20 376/072-105 3 376/060-3
B40 W.D. 1967-68 398/6 26mm 376/100-210 376/076-25 396/010
B40 Australian W.D. 1967 L626/4 26mm 376/100-130 124/026-20 622/122-106 2 622/060-3
B44 Victor Racing 1965 389/221 1 5/32” 376/100-260 376/076-25 376/072-106 3 389/060-3.5
B44 Victor Grand Prix 1965-68 389/221 1 5/32” 376/100-260 376/076-25 376/072-106 3 389/060-3.5
B44 Victor Enduro 1966 389/235 1 5/32” 376/100-330 376/076-25 376/072-106 3 389/060-3.5
B44 Victor Special 1967-68 R930/1 30mm 376/100-220 124/026-25 622/079-107 3 928/060-3
B44 Victor Roadster 1967-68 R930/11 30mm 376/100-230 124/026-25 622/079-107 2 928/060-3
B44 Victor Special (U.S.A.) 1969-70 R930/38 30mm 376/100-240 Bush 622/122-106 1 928/060-3.5
B44SS Shooting Star 1969-70 R930/38 30mm 376/100-240 Bush 622/122-106 1 928/060-3.5
B44SS Shooting Star 1970 R930/40 30mm 376/100-240 Bush 622/122-106 1 928/060-3.5
B25FS Fleetstar 1968-70 R928/10 28mm 376/100-170 Bush 622/122-106 1 928/060-3.5
B25FS Fleetstar 1971-72 R928/16 28mm 376/100-170 Bush 622/122-106 1 928/060-3.5
B50SS Gold Star 1971-72 R930/62 30mm 376/100-200 Bush 622/122-106 1 928/060-3.5
B50T Trail 1971-72 R930/62 30mm 376/100-200 Bush 622/122-106 1 928/060-3.5
B50MX Motorcross 1971-72 R932/18 32mm 376/100-250 Bush 622/122-106 1 928/060-3.5
B50MX Motorcross (TR5MX In USA) 1973-74 R932/28 32mm 376/100-180 or 376/100-250 Bush 622/122-106 3 928/060-3.5
C Series Singles 250cc
C10 (Ex W.D.) 1940-45 274D/3A 25/32” 4/042-90 4/061-106 3 4/0524 3A
C10 1946-53 274K/3A 25/32” 4/042-90 4/061-105 2 4/0524 3A
C10L 1954-55 274BT/3EG 25/32” 4/042-90 4/061-105 2 4/0524 3EG
C10L (Home & Export) 1955-56 375/2 25/32” 376/100-120 376/076-25 376/072-105 2 375/060-3.5
C10L (With Air Filter) 1955-56 375/2 25/32” 376/100-85 376/076-25 376/072-105 2 375/060-3.5
C10L (Home & Export) 1957 375/30 25/32” 376/100-120 376/076-25 376/072-105 2 375/060-3.5
C11 1946-48 274L/1AT 25/32” 4/042-80 4/061-106 3 4/0524 1AT (7°)
C11 1949-53 274AU/1DA 25/32” 4/042-80 4/061-106 3 4/0524 1DA (7°)
C11G 1954 274BU/1EH 25/32” 4/042-80 4/061-106 3 4/0524 1EH (7°)
C11G (for Air Filter) 1955 375/4 25/32” 376/100-100 376/076-25 376/072-105 3 375/060-3.5
C11G (Home & Export) 1955 375/4 25/32” 376/100-140 376/076-25 376/072-105 3 375/060-3.5
C11 (Home & Export) 1957-8 375/25 25/32” 376/100-140 376/076-25 376/072-105 3 375/060-3.5
C12 1949 276DM/1B 1” 4/042-150 4/061-106 2 6/0524 1B
C12 1956-7 375/4 25/32” 376/100-140 376/076-25 376/072-105 3 375/060-3.5
C12 (Home & Export) 1957-8 375/25 25/32” 376/100-140 376/076-25 376/072-105 3 375/060-3.5
C15 Trials & Std Model 1959-61 375/34 7/8” 376/100-140 376/076-25 376/072-105 3 375/060-4
C15 Competition Scrambler 1959-60 376/222 15/16” 376/100-180 376/076-25 376/072-106 2 376/060-3
C15 Scrambler & Starfire 1960-61 376/258 1 1/16” 376/100-240 376/076-25 376/072-106 2 376/060-3.5
C15 Star (Home) 1961 376/270 1” 376/100-180 376/076-25 376/072-106 3 376/060-3.5
C15 Scrambler (U.S.A.) 1962-63 376/258 1 1/16” 376/100-240 376/076-25 376/072-106 2 376/060-3.5
C15 Scrambler (Home) 1962-63 375/34 1 1/16” 376/100-240 376/076-25 376/072-106 2 375/060-3.5
C15 (U.S.A.) 1962-65 376/270 1” 376/100-180 376/073-25 376/072-106 3 376/060-3.5
C15 Police, Trials, Pastoral 1962-67 375/51 7/8” 376/100-140 376/076-25 376/072-105 3 375/060-4
C15 Scrambler 1963-65 376/304 1 1/16” 376/100-190 376/076-25 376/072-106 2 376/060-3.5
C15 Sports Star (U.S.A.) 1962-65 376/290 1 1/16” 376/100-210 376/076-25 376/072-106 2 376/060-3.5
C15 Sports Star (Home) 1962-66 376/281 1” 376/100-200 376/076-25 376/072-106 2 376/060-4
C25 Barracuda 1967-68 R928/1 28mm 376/100-200 124/026-25 622/122-106 2 928/060-3
D Series 125-175cc Singles
D1 Bantam 1947 261/001D 5/8” 4/042-75 259/069-106 2 161/0515 Combined with Mix. Chr.
D1 Bantam 1948 261/001D 5/8” 4/042-75 259/069-106 2 161/0515 Combined with Mix. Chr.
D1 Bantam 1949 261/001D 5/8” 4/042-75 259/069-106 2 161/0515 Combined with Mix. Chr.
D1 Bantam 1950 261/001D 5/8” 4/042-75 259/069-106 2 161/0515 Combined with Mix. Chr.
D1 Bantam 1951 361/1 5/8” 4/042-75 259/069-106 2 161/0515 Combined with Mix. Chr.
D1 Bantam 1952 361/1 5/8” 4/042-75 259/069-106 2 161/0515 Combined with Mix. Chr.
D1 Bantam 1953 361/1 5/8” 4/042-75 259/069-106 2 161/0515 Combined with Mix. Chr.
D1 Bantam 1954 361/8 5/8” 4/042-75 259/069-106 2 161/0515 Included
D1 Bantam 1955 361/8 5/8” 4/042-75 259/069-106 2 161/0515 Included
D1 Bantam 1956 361/8 5/8” 4/042-75 259/069-106 2 161/0515 Included
D1 Bantam 1957 361/8 5/8” 4/042-75 259/069-106 2 161/0515 Included
D1 Bantam 1958 361/8 5/8” 4/042-75 259/069-106 2 161/0515 Included
D1 Bantam 1959 361/8 5/8” 4/042-75 259/069-106 2 161/0515 Included
D1 Bantam 1960 361/8 5/8” 4/042-75 259/069-106 2 161/0515 Included
D1 Bantam Minor 1957-61 361/18 5/8” 4/042-75 259/069-106 2 161/0515 Included
D1 Bantam 1962-63 361/18 5/8” 4/042-75 259/069-106 2 161/0515 Included
D1 Bantam G.P.O. 1962-63 363/13 0.475 363/044-55 376/076-15 363/018-103 3 363/0783
D1 Bantam (Competition) 1951-53 361/2 5/8” 4/042-75 259/069-106 2 161/0515 Combined with Mix. Chr.
D1 Bantam (Competition) 1954-59 361/9 5/8” 4/042-75 259/069-106 2 161/0515 Included
D3 Bantam Major 1954-58 523/1 11/16” 4/042-90 223/016-107 3 223/0125 Included
D3 Bantam Major Comp. 1954-55 523/2 11/16” 4/042-90 223/016-107 3 223/0125 Included
D3 Bantam Major 1956-60 523/3 11/16” 4/042-95 223/016-107 2 223/0275D Included
D3 Bantam Major Comp. 1956 523/4 11/16” 4/042-90 223/016-107 2 223/0275D Included
D3 Bantam Major 1957-59 523/5 11/16” 4/042-95 223/016-107 2 223/0275D Included
D5 Bantam 1958 375/31 7/8” 376/100-140 376/076-25 376/072-105 2
D5 bantam American 1957-60 361/23 5/8” 4/042-25 259/069-106 2 161/0515 Included
D7 Bantam Super (Home & Export) 1959-61 375/31 7/8” 376/100-140 376/076-25 376/072-105 2 375/060-3.5
D7 Pastoral (Export) 1959 375/39 7/8” 376/100-150 376/076-25 376/072-106 3 375/060-3
D7 Pastoral (Export) 1960-61 375/40 7/8” 376/100-150 376/076-25 376/072-106 3 375/060-3
D7 Pastoral 1962-63 375/40 7/8” 376/100-150 376/076-25 376/072-106 3 375/060-3
D7 Bantam 1962-65 375/31 7/8” 376/100-140 376/076-25 376/072-105 2 375/060-3.5
D7 Pastoral (T.O.O.) 1962-65 375/50 7/8” 376/100-140 376/076-25 376/072-105 2 375/060-3.5
D7 (U.S.A.) 1963-65 375/56 7/8” 376/100-110 376/076-25 376/072-105 2 375/060-3.5
D7 De-Luxe and Silver Bantam 1966 375/60 7/8” 376/100-100 376/076-25 376/072-105 2 375/060-3.5
D7 G.P.O. 1966 32/23 11/16” 4/042-15 32/033-104 363/018-103 3 32/0462 Included
D10 Bantam 1966 376/323 1” 376/100-180 376/076-15 376/072-105 2 376/060-3.5
D10 Supreme, D10 Bushman, D10 Pastoral. 1967 R626/3 26mm 376/100-150 124/026-25 622/079-105 2 622/060-3
D10 G.P.O. 1967 32/23 11/16” 32/023-85 4/042-15 32/033-104 3 32/0462
D14/4 Supreme, D14/4B bushman, and D14 Pastoral. 1968 R626/12 26mm 376/100-160 124/026-25 622/079-105 2
D14/4S Bantam Sports 1968 R626/13 26mm 376/100-160 124/026-25 622/079-105 2 622/060-3
D175 Bantam 1969-71 R626/17 26mm 376/100-180 Bush 622/122-105 2 622/060-3.5
D175 Bushman 1969-71 R626/17 26mm 376/100-180 Bush 622/122-105 2 622/060-3.5
Gold Star 500cc Singles
ZB32 Gold Star 1949-54 276DR/1AT 1” 4/042-150 4/061-106 3 6/0524 1AT (7°)
ZB32 Gold Star (Racing) 1949-54 T10TT9 1 1/16” 376/100-320 3970/109 4 175/3117 14/534 (7°)
BB32 Gold Star Clubmans 1953 T10RN 1 3/32” 376/100-450 185/109 4 185/366 302/17 (Remote)
CB32 Gold Star Scrambles 1954 10TT9 1 3/32” 376/100-350 3970/109 3 175/3117 302/10 (15°)
CB32 Gold Star Clubmans 1954 T10GP 1 3/32” 376/100-210 316/065-109 1 316/0106 302/17 (Remote)
DB32 Gold Star Clubmans 1955-61 T10GP 1 3/16” 376/100-280 316/065-109 4 316/0105 504/2
DB32 Gold Star Clubman (Export) 1959-60 T10GP 1 3/16” 376/100-280 316/065-109 4 316/0105 302/17 (Remote)
ZB34 Gold Star 1949-54 T10TT9 1 5/32” 376/100-360 3970/109 4 175/3116 14/534 (7°)
BB34 Gold Star Clubmans 1953 T10RN 1 3/16” 376/100-520 185/109 4 185/367 302/17 (Remote)
CB34 Gold Star Clubmans 1954 T10GP 1 7/32” 376/100-260 316/065-109 2 316/0107 302/17 (Remote)
BB34 Gold Star Scrambles 1954 10TT9 1 5/32” 376/100-360 3970/109 4 175/3117 302/10 (7°)
DB34 Gold Star 1955 T5GP 1 3/8” 376/100-330 316/065-109 4 316/1047 302/17 (Remote)
DBD34 Comp Gold Star Scrambler 1956-63 389/13 1 5/32” 376/100-320 376/076-25 376/072-106 2 389/060-3
DB34 Gold Star Clubmans 1956-61 T3GP 1 1/2” 376/100-350 316/065-109 3 316/4134 302/17 (Remote)
DBD34 Gold Star (Export) 1958-61 T10GP 1 5/32” 376/100-240 316/065-109 3 316/0105 302/10 (15°)
DBD34 Gold Star (Export) 1959-60 T3GP 1 1/2” 376/100-350 316/065-109 3 316/4135 302/17 (Remote)
DBD34 Comp Gold Star Scrambler (Export) 1959-60 389/35 1 5/32” 376/100-320 376/076-25 376/072-106 2 389/060-3
DBD34 Gold Star (Export) 1959-61 T3GP 1 1/2” 376/100-350 316/065-109 3 316/4134
DBD34 Comp Gold Star Scrambler 1960-61 T10GP 1 5/32” 376/100-240 316/065-109 3 316/0105 504/2
DBD34 Gold Star Scrambler (U.S.A.) 1961 389/61 1 3/16” 376/100-320 376/076-30 376/072-106 4 389/060-4
DBD34 Gold Star Catalina Scrambler 1962-63 389/61 1 3/16” 376/100-320 376/076-30 376/072-106 4 389/060-4
DBD34 Gold Star Clubmans (Home) 1962-63 T3GP2 1 1/2” 376/100-350 376/076-25 316/065-109 3 316/4134 510/1
DBD34 Gold Star (U.S.A.) 1962-63 T3GP2 1 1/2” 376/100-350 376/076-25 316/065-109 3 316/4134 510/1
M Series 500 Singles
M20 1940-45 276C/1B 1” 4/042-170 4/061-106 2 6/0524 1B
M20 1940-45 276L1E 1” 4/042-170 4/061-106 2 6/0524 1E
M20 1946-54 276C/1B 1” 4/042-170 4/061-106 3 6/0524 1B
M20 1955-56 376/21 1” 376/100-240 376/076-30 376/072-106 3 376/060-5
M21 1940-45 276P/1B 1 1/16” 4/042-160 4/061-106 2 6/0524 1B
M21 1946-54 276BR/1B 1 1/16” 4/042-160 4/061-106 2 6/0524 1B
M21 A.A. Only 1949-53 276DZ/1B 1 1/16” 4/042-160 4/061-106 2 6/0524 1B
M21 1955-56 376/23 1 1/16” 376/100-250 376/076-30 376/072-106 2 376/060-5
M21 A.A. Only 1955-60 276DZ/1B 1 1/16” 4/042-160 4/061-106 2 6/0524 1B
M21 1957-61 376/88 1 1/16” 376/100-250 376/076-30 376/072-106 2 376/060-5
M21 A.A. Only 1960 376/251 1 1/16” 376/100-250 376/076-30 376/072-106 2 376/060-5
M33 (Home) 1957-60 376/85 1 1/16” 376/100-260 376/076-25 376/072-106 3 376/060-3.5
M33 1949-54 289G/1AT 1 1/8” 4/042-200 29/076-106 3 29/0624 1AT (7°)
M33 (Home) 1955-57 376/10 1 1/16” 376/100-260 376/076-25 376/072-106 3 376/060-3.5
Misc BSA Motors & Scooters
Winged Wheel 1963-54 335/1 .390” 124/025-30 335/018-0745 3 335/0143 Combined With Mix. Chr.
Winged Wheel 1955-58 335/1 .390” 124/026-27 335/018-0745 2 335/0143 Included
Beeza Scooter 1956 363/2 25/32” 363/044-100 376/076-20 363/018-105 3 363/0124
Dandy 1956-61 365/1 1/2” 124/026-35 308/045-0745 3 365/0053 Included
Sunbeam Scooter 1958-60 363/9 13/16” 363/044-130 376/076-15 363/018-106 5 363/0923
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2 thoughts on “Amal Concentrics Tuning and Jetting”

  • jim krist

    I have a 68 T100C – it doesn’t have a external pilot jet but after 45 some years who knows what it should have – SO how do i tell if the carb was designed for a external jet or imbedded pilot jet (bush)? Would adding a external jet change anything thanks Jim Krist

    • Nick Willcutt

      The only Concentrics that use and external pilot jet would be those that don’t have a pressed in pilot jet bushing. Removing the pilot air screw and shining a pen light into the opening should reveal a brass object. This type of pressed in jet was standard on 4 stroke Amal Concentrics from 1969 till present. Only with the release of the new Premier carb has the bushing been superseded by the adjustable plug/jet. You might note the new production carbs retain the threaded hole that faces down into the float chamber. This feature is retained for the 2 stroke applications the Amal still produces carburetors for.

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