Motorcycle Repair: engine run problem, 1982 GS850G Suzuki, vacuum line, leakproof seal

Question
Hi Chris, sure hope you can help me, I can't solve the problem.  The engine only runs on choke. I've tore the 4 carburetors apart twice and it still runs the same.  The vacuum diaphrams on top are all fine and the jets are all clean. The vacuum line to the fuel petcock is fine and the petcock is clean,diaphram good, filter is clean,etc.. Carb fuel bowls etc are clean and work fine.  With the air cleaner off and engine running the carb vacuum slides do not open in response to the butterfly throttle valves.  Otherwise it looks like a new bike ,39000 wellcared for miles. Please help if you can. Thank you  

Answer
Hi Eugene.
 You may want to check the manifold connections to the carbs and to the engine.  They could be leaking.  Also the manifolds themselves could be cracked and leaking.

You should check the connections of the exhaust headers.  If they have loosened up any, that could also cause problems like you have described.

If the slides are not moving, then that would indicate a leak in the rubbers or the seals in the carbs.  They may have worn out and need replacement.  Thos slides move on a vacuum system that depends on a tight, leakproof seal.

Start with those and see what you find.
Good luck.
FALCON