My 14 year old son got this Honda trx300 for free. The guy told us that the motor is bad. We got it home, strip and clean the carb, set the valves and install a new spark plug. The atv is running now the the motor is not bad. It start right up and idle nicely the problem is when riding it and during exceleration it hesitates intermittently. I puled the spark plug and grounded it to the motor, i can then see it is sparking good and stop sparking for a little bit. I have checked all the electrical connections i could find. I would appreciate any help in finding the problem. He walks around with a long face like a thirsty donkey and is driving me nuts to fix this new toy

 

hmm, i would check to make sure the flywheel magnets are not cracked or rusty, also make sure the stator and coils are not rusty or damaged, causing the magnetism to get weak and cause loss of spark intermittently. That, and check the wiring connections, look for corrosion or broken wires. good luck.

 

Good advice.

 

Thanks guys I have been working on this thing the hole day this is what happens, when I am riding and turn to the right it starts to sputter and lost power, when I turn to the left it stops sputtering and picks up power. I have checked all the wiring in the steering colum and along the frame. I think it must be in the motor, is this possible.

 

sounds an awful lot like a parking brake rev limiter issue.. when you turn the bars it pulls those wires. could be shorted inside the sheathing and you woulndt see it.

 

I agree with OneFly. It sounds an awful lot like a short to me, although I don't believe the trx300ex has a parking brake electrical shut off. But it may be in the kill switch wiring. Like OneFly said, if it's under the sheathing of the group of wires it won't be easily visible.

 

Check out this post here bollie Baffeling 300 ex problems

 

heck rod i forget hondas are differnt sometimes.. how about just a rev limeter issue. Reverse limeter grounding out or sompin.

 

Wow OneFlyCowboy my problem is exactly the same as the one in the link you posted. the guy never posted what the problem was or if he got it sorted out. One question is there suppose to be oil behind te left motor cover where the stator is located. A lot of oil ran out when I opened that cover

 

I am pretty sure that should be dry. I think you have a bad crank seal.