Hiccup on load when hot?

[Rufes1]

Hey all,

I have a honda XLX250R , Its had a rebuild and was running great. I tuned it and it was running great, starts first kick when cold with full choke and runs great fro about the first 30 mins.

Then when it gets hot at about 5,000rpm+ with id say 60%+ throttle it hicupps and struggles to make power or build revs.

Im wondering do you think its running rich or lean? Ive just replaced the plug so not that...

The way I tuned it was:

Started the bike, let it get hot, then wound the fuel screw out. then slowly wound it in until it raised to a peak rpm, then backed it out 1/4 turn..

If anyone could point me into the right direction id really appreciate it

cheers

[Woody_393]

Sounds like you are maybe too rich up on the top. I'd start by lowering the clip on the needle (raising the needle) and see if that helps. If it does, you may need a fatter main.

[Pretendo]

um i thought you drop the needle by raising the clip twards the top of the needle to lean out the mixture through out the throttle range. Theres a good chance that the powerrvalves are just not doing there job and opening up as thoght the should. this i have personally seen on alot of mx bikes. the popwervavles just might not be doing there job, wheather or not there cloged up with sludge or if there just malfunctioned. make sure to check that out. i would check it before playing with dangerously lean conditions to see if the bike stops the sputter.

Rare chance, but it could also be an ignition coil or cdi box, but those are hard to test. go thru the steps and then get back to us.

[Woody_393]

Uhm you are 100% correct

[Big Maico 393]

Recheck your valves!

Does it seem like it has less compression when hot? valves might be just a little tight & when it gets hot it loses compression & power.