I have a 1985 TRX 125. When I drive it for about 40 minutes, the motor comes really hot. Is this an overheating problem? When it comes hot, and I am on a straigh area, I feel that the motor occasionnaly looses a very little bit of power, enough to hear the motor die just a little, is that a symptom of overheating? It will heat up A LOT faster when I'm running in a higher RPM range, so I just keep it on a higher gear usually. We just replaced the piston last year and the guy told us that their was actually no wear in the motor at all! Could this be a spark plug question. I noticed my dad is not running the exact number spark plug in the machine that the book says, could this be why it heats up? Any help is more then welcomed.

 

Yes that plug might be your problem
you need a NGK# DR8ES-L
smaller numbers run hotter(ex. a DR7ES-L)
what plug is in it now?

 

If you think your motor is running hot internally, you need to check your plug. Run the TRX at speed, kill the engine with your kill switch and coast to a stop. Then check your plug.

 

My foreman 400 gets pretty hot before the fan kicks on so this may be normal. It will warm up your legs pretty good before the fan kicks on.

 

I am currently running B9EA, or maybe D9EA. I'm not sure if it's the B or D. More input is welcomed.

--JasonJ

 

You could be running lean. I would check the gas cap. The fuel tank vents through the cap, and over the years I have replaced many of these that go bad. The main symptom is dying at higher speeds (when you are using more gas). You can quite easily check this out. Make sure you have quite a bit of fuel in the tank, over half full. You need an open container that holds about a pint. Now would be a good time to put the smoke out. Gas VERY explosive in an open container!! Turn the gas valve off and take out the two small screws that hold it in place. Pull it a little away from the wheeler and hold the container under it and turn the gas on and watch the flow. It should flow steadily. If after several ounces it seems to want to quit flowing or slow down, open the gas cap. If the flow resumes steadily the gas cap is bad and restricting the fuel flow to the carb. If your cap checks out, you may want to have a look inside the carb at the main jet and check it for partial obstruction, wrong size etc. Sometimes it's best just to fork over a few bucks and replace it.