First off, I’ve been a member here for a few years and have found lots of great information here. A couple weeks ago I was getting the quad ( 2004 Honda Rubicon TRX500FA) ready for as hunting trip. I must say it was sitting for about a year and a half. I put a new battery in it and it started, then died at the same time I caught a whiff of bad gasoline.

First issue: Pulled the carb apart for cleaning and after I put it back together it ran great, or so it seemed. The first problem is that when going downhill for more than a couple hundred yards it will sometimes spit, sputter and die. I couldn’t narrow it down if it died more often on steeper down hill with more fuel in the tank or less steep with less fuel or vice versa. It will start up after sitting for about 5 minutes and run great just like it never happened. I don’t know exactly what the problem is. It doesn’t matter how much fuel is in the tank from almost empty to 3/4. I am thinking it could be a sticky float, float valve or maybe even the lower part of the in-tank screen set could be clogged and when going downhill the fuel level in the tank is below the clogged portion of the screen. Could it be the throttle position sensor? Any ideas where to start?

Second issue: The engine stop switch has to be moved slightly left for the engine to turn over. If it is in the center position on/detente the engine will not turn over. Is there a way to fix the switch? The only way I have found to replace it is to buy the entire left handlebar switch assembly.

Thanks in advance

Damon