Stumped on starting problems.

[vtgs500f]

Looking for some advice to my starting issue.

Bike cranks fine but will not fire most of the time. Occasionally it will fire and start, but will not idle well. After it warms up it will stay running but the idle races and I cant get it to come down.

Tested coils, ignition, spark all looks ok.
Took the carbs off, took them appart cleaned them, dumped out the gas put in clean gas, verified flow out of the petcock. (I removed the old vacum petcock it is now just a basic on/off.)
Bike is jetted with the typical Budha recommended jetting, KN filter and Exhaust.

It seems if I cover the air side of the carbs, so there is a very minimal opening it does start a higher percentage of the time.

This all started after a day at the track, rode for three sessions no problems.  fourth session was a red flag came in shut it off. When they let us back out I could not start it.
An hour later I was able to start it and go back out one more time, but that was it have not been able to get it running since.

Any ideas?
Thanks, Alex

[jdoorn14]

I may be way off here, but it sounds like you may need to check valve clearance. How long has it been since they were checked?

[vtgs500f]

I checked it maybe 10 hours ago.

But the next think I was going to do what open it and check valve timing.
Like I may have jumped a tooth on the chain while pushing it on the track.

[Dizzledan]

Pull your cam chain tensioner and see if it has failed. Given the fact that if you cover part of the intake it has a higher chance of starting I think you're right on with the timing jumping a tooth. Could be a bad tensioner, could be the cam chain guide/s broke. What's your oil look like? I assume since you were at the track you've changed it.

[vtgs500f]

The oil was clean, no bits and pieces, nothing in the filter. I will open it up this weekend check the tensioner and guides. As well as the timing.

Thanks for confirming my thoughts Dizzledan.