I think I blew up my kfx. The only thing I did was change the needle jet one position to make it run a bit leaner. I went for a drive down the road, not going very fast, 4th gear 1/2 throttle and then she just quit. It wouldn't start again, not even fire or make an attempt to fire. About 10 minutes later I tried again and it started up. I started driving home and the same thing.

I changed the needle back to the original position and went for a drive. Everything seemed fine until I pulled into my driveway and it shut off again. Then, sitting in my garage I started it, it idled for a minute then shut off and would not start again. Whats going on?

 

sounds like to me you have a carb problem, you might have leaned it out to much and hurt the motor

 

Try changing your spark plug.

 

was the exhaust popping? or get hot!! i always keep mine on the rich side.maybe bad gas or some trash in carb.
i had a problem like that once, i was going back and forth in the field trying out a new cdi.id mack 2 hard passes and it would die,hard to start.get it going make 2 passes and it would do it again. changed cdi's drained gas and checked jets.ran fine after that. i think i had some bad gas.good luck i hope you find the problem.

 

You DO NOT want to lean out these new engines at all.... they are running pretty lean from the factory to keep emissions low........ leaning them out more will only cause problems.......

I would take a good look at your plug and see if it shows an extreme lean condition........

 

I took the carb apart and cleaned it. In the midst I found a chunk of dirt in the main jet. Blew it out, put everything back together, runs good now. Spark plug is fine. Light brown colour.

 

cool, glad you found the probem

 

glad you found the problem! i hope you take everybodies advise and stay on the rich side. if you run it lean it will tear it up and you'll wish it was just trash in the carb.

 

i would watch your quad the same thing happend to my blaster it just quit one day i wasnt going fast so i did the same thing cleaned the carb and there was alot of dirt in it then it ran fine till i was 30 miles in the bush when it quit again so i took it in and my piston was melted