Amal 93 carburetor jet sizes
- Thread starter rhino64
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The obvious answer is stock jetting, however it depends on which carburetors you are using. The original 1967 concentrics used a different needle and needle jet than the later ones. The original carbs had a needle jet with the orifice (where the needle controls the flow) at the top, no bleed holes, and used with a short needle. The original size was a 107. The later carbs have the orifice at the bottom of the jet with bleed holes (in the hex). That is a more efficient design, and a 106 would be the correct size with the longer three ring needle, just like an early Commando. The main jet was 250, and screw in pilot jet (if you have one) is a
25. Oversize pistons, and slightly more compression won't change things.
Mike B.
25. Oversize pistons, and slightly more compression won't change things.
Mike B.
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Mike B said:
What if mine are a 106 needle jet (no holes) - short needle with 3 grooves?
Can I upgrade to the long needle, 107 needle jet with orifices or should I just leave the original set in? If I stick with original 106 needle seats what should the jetting be?
I do have pilot jets.
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rhino64 said:
The later '4-stroke' needle (622/124) has two identification rings (these are not the clip grooves).
http://amalcarb.co.uk/rebuilding-mark-1 ... arburetter
http://amalcarb.co.uk/4-stroke-conversion-kit.html
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rhino64 said:
The best I can do is give you the original P11 carb spec. from the '63 - '68 parts list;
Throttle valve (slide) = 3.0
Needle, 928/063 (original 3 ring needle)
622/079, 107 Needle jet (original needle jet)
Main jet ("with air filter") = 250
Pilot jet = 25
rhino64 said:
According to the parts list, the P11 carbs were 930/7 and 930/8 [Edit] (and which matches the Amal carb numbers for P11). Needle jet is 107 according to Amal's spec. although the 4 stroke conversion kit contains a 106.
http://amalcarb.co.uk/carbspec/carburet ... s/id/5464/
L.A.B. said:
Hi Les,
sorry, but why if Amal says that "Needle 928/063" is for two stroke the P11 setting require it?.
On my P11 carburetors 930/7/8, i use all the carb specs but not the 928/063 throttle needle and use the common 622/124 fitted on all my Commando.
What is the real difference?
Thank you.
Piero
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pierodn said:
928/063 (3 ring) needle was the 'two stroke' needle ONLY AFTER the introduction of the 4 stroke needle and needle jet in 1969.
Before then, the 928/063 was used for both 2 strokes and 4 strokes.
pierodn said:
Yes, as the 622/124 (2 ring, 4 stroke) needle when used with the later 4-stroke needle jet and jet holder should perform better than the original P11 carb specification.
http://amalcarb.co.uk/rebuilding-mark-1 ... arburetter
(I believe the 4 stroke needle and jet were actually introduced during 1968. The Amal Concentric Mk1 introduced late '67)
https://www.princeton.edu/ssp/65-cub-da ... itbike.pdf
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Hi Les,
https://www.princeton.edu/ssp/65-cub-da ... itbike.pdf
That is a great pdf and should go in our technical sticky.
if not already.
Cheers,
Thomas
https://www.princeton.edu/ssp/65-cub-da ... itbike.pdf
That is a great pdf and should go in our technical sticky.
if not already.Cheers,
Thomas
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