monstergirl said:
ok this is the problem. the idle is weak low. spark plugs seem ok, but bike doesn't seem to be getting enough gas. i let it warm up. but idles really rough low. and will occasionally stall. could it be bad gas? fuel filter? please help.
1- Spark Plugs - They can seem ok, how about the wires and coil? if you have some mileage on the bike and its been a while since they were changed I would get new plugs and wires.
2 - Gas - Have you checked all your fuel lines, make sure they are not pinched, not leaking, good overall visual inspection? Again how many miles and when was the filter last changed? If the bike has been sitting all winter with a full tank of gas, it will go bad, gasoline will only last sitting for a month or two at most. Look inside the tank and around the fuel cap. See any rust? Rust can buildup and cause obstructions to fuel pumps, lines and injectors.
Now a lot of fuel problems can be fixed with a simple method of a fresh tank of gas and some wide open throttle. Especially if the bike has been sitting for a while.
Other causes that have to have a dealer or someone experienced check. TPS (throttle position sensor), Coil, Voltage regulator/rectifier
Engines are like human bodies, they need 3 things to operate, Air/fuel/Electricity, work though a process of deduction, starting with the easiest, fuel.
Hope that helps