What is the significance of "R35" carb stamping?
- Thread starter jimbo
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jimbo said:
(932) R35 and L36?
"Will have bigger mains" than what, exactly? What are you comparing 35 &36 with?
jimbo said:
R35 & L36 would be the standard spec. carbs for an 850 Mk2.
260 mains
.106 needle jet
3.5 slide
928/104 needle
928/107 spray tube
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MK2A had smaller mains due to black cap silencers, also the black plastic air filter too but my MK2A has peashooters fitted and needed 260 mains to run full throttle so I doubt the air filter is contributing much in the way of difference to how the engine runs.
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"R" refers to right hand side carb, tickler on the right side. The number is only AMAL reference to how the unit was set up....slide cutaway, jetting, needle...etc. All of this is changeable and the number is only significant to configuration at AMAL for specific purchase requirement at the motorcycle manufacturer. I don't have a copy, but have see reference lists from AMAL that decipher the number codes and application. I would think Roy Bacon used this in his Restoration series of books.
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jimbo said:
260, 850 Mk1 (Amal 932/29 &30).
230, Mk1A and maybe also early Mk2A according to Bacon. (932/31 & 32).
260, Mk2 (932/35 & 36).
220*/230*, Mk2A and Mk3 (932/33 & 34).
*This can vary depending on the source of the information. For instance, the Mk3 parts book lists the main jet as "220", but it's "230" in the Mk3 manual.
L.A.B. said:
220 and 230 main jets are only one size apart in the world of Amal, after all.
Not exactly life changing stuff.
A true fanatic could well change between them for hot days and cold nights riding.
But Amals (and other makers) one-size-suits-all approach means you would barely pick the difference in performance and engine temps by not so changing them.
You can buy little variable-main-jet thingies for monoblocs and sidefloat carbs, for riders who insist on having it just right.
Can tweak them on the fly even.
Not sure I have seen them for concentrics, so maybe it really doesn't matter...
Brooking 850
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+1 Rohan
When setting up my race bike motor initially with the 32mm Premiers, standard Vv's and manifolds,it would take a big step of 2 or 3 jet sizes to get any significant changes to plug colours and or dyno out puts especially in the WOT positions.
It is 0.0015" difference from one size to another across the orifice diameter.
Regards Mike
When setting up my race bike motor initially with the 32mm Premiers, standard Vv's and manifolds,it would take a big step of 2 or 3 jet sizes to get any significant changes to plug colours and or dyno out puts especially in the WOT positions.
It is 0.0015" difference from one size to another across the orifice diameter.
Regards Mike
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