Zachary Coombs

The plug gets super hot too, is that what you mean? Plus now it’s back to backfiring like crazy before it even gets hot, if it’s a lean condition how can find what’s causing it?

Took off the whole exhaust everything was fine except for some damage to a fitting, oil filter was a little loose so I tightened it by hand. 

Will take off exhaust and check oil filter today, I ordered a new thermistor. Will get back to you in a few hours.

I haven’t taken it off but I’ve power washed it and used and a hose to try to get any mud out, I can see through it for the most part. The engine isn’t painted. The guy I bought the quad from said it has less than 8 hours riding time and he let it sit for about 10 years. Everything was fine for the first 10 rides after I bought it, I decided to change the oil and oil filter, the air filter and the spark plug and that’s when it started giving me problems. Since then I’ve cleaned the carburetor, bought a new battery, and the carb boot had tear in it so I replaced that. The fan never came on once it started overheating, The thermistor was connected to the top of the solenoid which I found had no voltage so I connected it to the bottom that’s powered straight to the battery, the weird part is the starter is still connected to the top and works fine?. At first it seemed like a lean condition with it backfiring but now it’s just running way too hot and loses power/backfires. Any ideas?

So 2 wires go to the thermistor where it screws into the hose, the blue jump goes to the solenoid (powered off the battery) and the other one connects to the fan. It’s also grounded to the bolt 

Sorry I forgot to mention it’s air cooled, so it’s not really a radiator it’s a oil cooler theres no water pump. The thermistor switch seems to already be jumped to the solenoid, don’t know if that’s from the factory since I bought it used. The oil cooler gets really hot after a few minutes, the fan does run very fast. Does this make a difference?? Thanks again

Hello, I’m new to this forum, I have a 2007 trail boss 330 that’s been overheating after about 5 minutes of riding. No problems before it overheats from a cold start but then it backfires and loses power. The fan comes on but the temp light doesn’t. I’ve had someone clean the carburetor, I’ve replaced the spark plug and air filter and put in a new battery. I also tried cleaning the radiator with a hose, Any help is appreciated, Thanks