high idle problems as well as hard starting

[lance shelton]

hello im new to the board and to the gs500 . my problem is i bought a 96 gs 500 and so far ive rebuilt the carbs and put on a new vacum petcock as well as cleaned the tank and new hoses. my problem is it starts hard and idles betwwen 4-5k  the cables are good and routed properly choke works fine carbs are sync by feeler guage, ive installed all new orings in the carbs as well as pilot jets and needle jet and the jet holder pilot screw out 2.5 turns on both. i have new intake boots as well and the floats are dead on. the only thing i see is when i get it warm up i can kill it and restart it and it will idle fine but when i hit the throtle its off to the races .until i kill it and restart it. i sprayed carb cleaner arond the head gasket and and base gasket and it picked it up and off to the races again until i kill the bike. im leaning on its a vacum leak at the gaskets but id like a second or more opinions. even when i sray carb cleaner around the new boots it picks up and theyre tight and new . please help im stumped and clymer is of no help.any advice will be greatly appreciated. also it does leak oil a little but ive never saw it coming from the gasket areas.

[beRto]

very common problem with the GS... once I adjusted the idle control screw (big brass bolt between the carbs) the problem went away. Make sure the bike is warm when you make the adjustment.

If this doesn't help you, it means you likely have a vacuum leak somewhere; do a search and you will find lots of suggestions for finding & fixing it.

[yamahonkawazuki]

aye, sometimes you can use a substance like carb cleaner, ( warning VERY FLAMMABLE) sprayed around boots etc, you know if youve got a vaccuum leak. when you cleaned carbs, how did you clean-em?, first thing i would check tho is the idle spped knob, also did you put new plugs in, when or after you cleaned carbs?

[lance shelton]

well i cleaned the carbs with cleaner as well as a small torch tip wire that would fit into all the holes .as far as the idle screw i could remove it all together and it would still race away . besides the head gasket leaking vacum im stumped by what else it could be everything in the fuel system as well as carbretour is new also.its getting me depressed to say the least.im going to mess with it this afternoon again check the floats as well my new boots. and inspect the outside of the head and intake for cracks. clymer has me baffled as well it shows two different ways to route  the fuel lines and the diagram on the gstwins site has the fuel tank petcock turned 180 degrees so that confuses me to which way is the right way to route my hoses. from the main to the reserve . anyway thanks for the response .

lance

[yamahonkawazuki]

emm clean the carbs thoroughly. remove them from the bike, completely disassemble them, get a can of carb cleaner ( comes in a gallon can) and soak it for 24 hours. re-assemble them, tehn re-install