Please help me fix my carbs bs38

[vincemoccio]

I've been having on and off carb issues. I have pod filters and non-baffled straight pipe exhaust. Recently installed Hugh's hand built PMA. I have Bs38s and on my 1978. Main jet = 145. Pilot = 45, I changed both. Mixture screw is at 3 turns. At first, my bike would not idol correctly, it would start then die. I pulled the carbs, cleaned the living heck out of them. Now, bike fires up perfectly but when I shift into 1st gear it revs very high especially when I hold the clutch in. I understand that this could be caused by a leak. But there is no leak when I tested it by spraying the intake boots with carb cleaner. Suggestions? I've read the carb guide on here over and over.

Thanks

 

[TwoManyXS1Bs]

Are you running a points ignition, with a worn-out spark advance?

 

[vincemoccio]

No, everything is fine.

 

[retiredgentleman]

You should replace the needle jet O-ring, if you have not already done that.

 

[vincemoccio]

What about the diaphragm?

 

[retiredgentleman]

What about the diaphragm?

The diaphram has nothing to do with a high hovering idle.

Things to look for with a high hovering idle:

-ATU shaft/weights not working (no lubrication/ worn out springs/parts etc)

-points gap/timing not correct

-mixture screws not adjusted correctly ( I use dead cylinder method)

-carbs not synchronized, ( both butterflys must be centred in the bores and must be able to close fully) ,use a manometer.

-BS38 needle jet O-ring passing extra fuel/air mixture

-air leakage around carb intake area

Maybe a combination of all of the above