Can anyone confirm the correct throttle slide size for my 500 G80S engine.
Carb type 389/1, pilot jet 30, main jet 260
engine number 28139
Should the throttle be 389/3 or 389/3.5?
Will I know the difference!!
Manuals say different sizes:-
AJS manual 389/3
Book of AMC 389/3.5 (After eng 27000
376/3 before 27000)
Fred Neil '55 389/3
'56 389/3.5
Graham grjackson@btinternet.com
G80S Throttle valve size
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G80S Throttle valve size
The difference will be that with a slide with 3/16" cutaway, it was running a shade rich coming off idle, and hesitate a little. So they increased the cutaway to 3.5/16". That is a very fine distinction !!
If you have a 3, be worth trying on modern petrol to see how it goes. If you are buying a new one, may still be best to go with the 3 - you can always file a bit off later on..
hopethishelps,
Rohan.
If you have a 3, be worth trying on modern petrol to see how it goes. If you are buying a new one, may still be best to go with the 3 - you can always file a bit off later on..
hopethishelps,
Rohan.
- TommoT
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G80S Throttle valve size
Yes it cold potentially make a big difference. A change from a #3 to a #3½ slide transformed my engine (-56 G80S). Went from lumpy running and fouled plugs to smooth running and only occasionally fouled plugs!
Good luck!
Tom M. (TM)
Good luck!
Tom M. (TM)
TommoT
Ride Your Motorcycle As If Your Life Depended On It - Cos' It Does!
Ride Your Motorcycle As If Your Life Depended On It - Cos' It Does!