Engine cut out

[Jacob 'Berg]

We were riding back to staging area after 4-5 hour ride yesterday on dirt road. Throttle position pretty constant at 1/2-3/4 throttle for about 15 minutes. The engine started to cut out and I thought I had run out of gas, so I immediately hit the kill switch and stopped. Still had gas in the tank. Started fine, ran fine the last minute or two it took to get back to the trucks.

Is it possible this was a partial/incomplete seizure of the piston? I may be borderline lean on the main circuit, but the bike did not run hot at all during the ride, which included a lot of 5th and 6th gear sand wash connectors.

Bike is starting and idling fine. Any input on whether I should take a look at the piston and cylinder, or if I am being paranoid, is much appreciated.

[iajim]

When you say the engine cut out, do you mean it acted like it was out of gas or did the engine (crank/ piston/ trans.) instantly stop rotating? If you were riding w/a slightly lean needle and main I doubt it would try to seize unless it was under a heavy load, like a long uphill. If you're nervous about the engine you could start by just pulling the exhaust for a look at the piston wall, then maybe the head to look at the cylinder. Just take it one step at a time, make sure the carb is OK; good inlet needle and seat, float is OK, no dirt or water in the float bowl. I have had problems before w/water in the float bowl, engine cuts out, but wouldn't restart w/o a carb cleaning. Let us know what you find. Jim.

[gasgasman]

Could be a spark plug.
Fuel cap vent could be sticking. Especially if it is one of those shorty vents.