Throat clearing GS1000

[sefu]

My 78 GS1000 has to clear it's throat before it runs well. When starting I have to give it full choke, and stay on the gas because it won't idle and #2 doesn't fire and it runs like crap and sounds worst. After about 5 mins it starts to sputter and backfire, on the intake and exhaust, but it seems to be clearing itself out or in this case drying the plug out. Then #2 starts hitting and it's off to the races. I suspect a cold air intake leak or bad valve adjustment on #2 and when it gets warmed up the #2 spark plug dries out, the cylinder starts to seal and then fires. After about a few backfires, it idles, runs smooth as silk, sounds excellent. If it sits and gets cold it's the same thing all over again. Am I missing something.

 

[TheCafeKid]

My 78 GS1000 has to clear it's throat before it runs well. When starting I have to give it full choke, and stay on the gas because it won't idle and #2 doesn't fire and it runs like crap and sounds worst. After about 5 mins it starts to sputter and backfire, on the intake and exhaust, but it seems to be clearing itself out or in this case drying the plug out. Then #2 starts hitting and it's off to the races. I suspect a cold air intake leak or bad valve adjustment on #2 and when it gets warmed up the #2 spark plug dries out, the cylinder starts to seal and then fires. After about a few backfires, it idles, runs smooth as silk, sounds excellent. If it sits and gets cold it's the same thing all over again. Am I missing something.

When have you adjusted the valve clearances last? And have you replaced the intake boot orings and assured your airbox is sealed correctly? I am assuming you've cleaned the carbs properly? Hard cold starting is a symptom of tight valves. As it warms up, the metals expand, the clearances prolly get a little closer to where they should be and it will smooth out, plus they just richen up naturally when warm. Should check those clearances! If you cant get a .04mm feeler gauge in there, I'd change the shim out to the next smaller size..