Newbie here guys, so be a little easy on me. I just bought my first quad, a 1996 300ex bone stock. Everything is original on it. The problem I'm having is when the motor is warmed up (about 30-45 minutes of ride time) the idle gets real high and the exhaust gets super hot. I mean so hot that my wife and I watched the plastic gaurd on the exhaust melt right off. Is this a air or fuel mixture problem with the carb. I took the carb off and cleaned the float, bowl and jets. I put a uni filter on it, and changed the oil and filter. It's still doing the same thing. Any help would be very appreciated. Thanks in advanced.

Larry

By the way the quad runs great when riding, very good throttle response

 

The little EX's tend to run hot. Do not let them sit still idling! It is air cooled, and when it isn't moving, it swtiches to being "prayer" cooled. When you are sitting, turn the engine off....don't sit there watching it melt.

Also, run an oil that will stand up to very high temperatures. I highly recommend Maxima Extra. 15W50 for hot weather.

Are you sure you aren't running lean??? With the UNI filter, you got rid of that cannister that is inside the stock filter, right? So did you do a rejet after that???

The changing idle thing is a little more puzzling. For the time being, just turn the idle **** down when it gets wamed up...

 

The only reason I put a uni filter on it is because I got it cheaper than the oem filter. I didn't know it would effect the machine, and by rejet, do you mean changing the size of the jets. Can you do that with a stock exhaust?

Larry

 

When You Cleaned the carb did you soak it or just clean what you could see because there are a lot of small ports that are not visable so you need to soak it and then wash with some spay carb cleaner and blow it out with compressed air then you need to reset the idle mixture screw so that it is not running rich cause that is why you get hot exhause is because to much fuel and not enough air in the mixture