1982 suzuki 750e carb trouble

[mcords]

I have a 1982 suzuki 750e the carbs were rebuilt and I set the floats to 22.4mm. I got the carbs running with ether and then with gas. If I reduce the thumb choke all the way the engine dies also if I try to rev the motor above 4000rpm the bike dies I had to turn the idle adjustment almost all the way out to get the motor to fire. It seems to run around 2500-3500rpm. The engine runs rough and seems to backfire. I reset the air screws to 1.25 turns and am wondering if the carbs need to be synched and if so is there a way to do it without the carb sticks?

[Aussie Steve]

I re-synced my carbs using one vacuum gauge attached to a brass four way switching valve...used in aquariums. I attached the valves to my carbs via small bore pipe and simply switched between them using the valves. I would set the pilots out further than 1-1/4 turns as this would be a very lean ratio....mine are about three and 1/4 out, although I am running a slip on pipe. Other areas to check would be lack of vacuum at the carbs...if CV type and partial blockage of fuel supply from the tank...possibly a vacuum in the tank...run without the tank cap on and see if this helps. Finally pull the plugs to see what colour they are to get a clearer picture of what is happening.

Good luck

[AZRyder]

Also might be a good idea to check the carb boots between the carbs and the engine. If they're old and cracked, you might have a vacuum leak there too. If you can get it to idle for a bit, spray some carb cleaner on the boots themselves and see if your engine revs up. Whichever boots they rev up on are leaking.