Honda TRX ATV Forum banner

97' 300EX Problem

3782 Views 2 Replies 2 Participants Last post by  d-dayman1
Hey all.... New to the forum here.

I need some help with an issue I've been having with a 300EX.

It had been sitting around for a while because it smoked really bad. When it was running it ran decent. It just didn't have the power it should have had. I had it running right before I rebuilt it. I put a new piston and rings in, as well as all new gaskets. Complete top end kit from Namura.

I cleaned the carb up, and put good gas in tank, because it was running rough when I first got it going again....

Now the quad is running good at idle, and up to 3/4 throttle with no smoke. However after 3/4 throttle it breaks up pretty bad. It doesn't bog down. It stays running at the higher rpm, but just wont climb anymore, and keeps sputtering....

I tried changing out the main jet. I tried a 120, 125, and 128. The 125 seems to be runnig the best. Stock was a 122. Just can't seem to figure it out.

Does anybody have any ideas????

1 - 3 of 3 Posts
How does your air filter look? Did you clean out the tank also.
Put a new air filter on it when I rebuilt it. When I dumped out the old gas I put some good gas in the tank and shook it around a little and dumped it. Then put the tank back on. That's all I did with the tank.
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.