starts fine runs rough after warming up
 

I've had my 98 SH for about four years. She was wonderful until about a month ago. I was about ten minutes into a ride when she started running really rough. Almost as bad as one dead cylinder but now quite. As long as she sits long enough to completely cool down she cranks and runs like new. Once she gets up to temp it happens all over again. She has new plugs and wires, and the carbs look clean and syncd. Nothing had been done for months before this started. Malfunctioning choke maybe? At a loss. Any ideas would be greatly appreciated.

Check the vacuum hose / petcock diaphram for starters...

will do, thanks Wicky. To clarify about nothing being done for months. I had been riding that whole time i just didn't have any thing done maintenance wise

I lifted the front of the tank and the vacuum hose on the petcock fell off by itself. i'll fix that and see if that does it and let you know. thanks again.

A recent post from one of he regulars said that a bad battery caused theirs to run like that. They replaced the battery and now it's perfect again.

James

Thanks Wicky. That vacuum hose to the petcock seemed to have fixed it! Thank you for your time!