Missing At WOT TRX250r

[akita8]

My sons 250r is missing at wot. We tried changing the cdi and spark plug (gapped at .010)and also inspected the connections. Do you think jetting could cause this problem? I was thinking it could be that the wiring harness is just old and the wires are breaking down inside the wire jacket.

 

Has anyone had a problem with older wiring harnesses?

 

The bike has:

310 Kit

ESR pipe

dyna fs cdi

39mm carb

Coolhead 19cc dome

BR8ES Plug NGK

 

Thanks for any help

 

He should have a banshee

[xXBlessedWithDeathXx]

i would think it was jetting. try running it with the air box lid off if its still on or look at your plug. i would think your to lean or not enough air to the carb. i would also gap between .25 and .28

Edited November 5, 2007 by xXBlessedWithDeathXx

[sheerider1026]

i would sell it and buy a banshee.. lol just kidding..

[black sunshine]

If you have a clymer's for it try testing the electrical, it has the values listed in there!

 

Although, mine checked out alright and it also has a miss on the top end :shoothead:

 

Changed the CDI and bought a new coil for the hell of it. Plugchop looked a lot better, but I noticed a definite miss on the top.

 

Compression is also good, I'm gonna do a thorough check on everything this winter, but I still have a weak spark after the new components.

[akita8]

We put in a Ricky Staor stator in about a year ago. I also swapped the coil out with another coil and it still missed. Maybe we'll have to try an aftermarket coil that has a litle more punch. The guys at ESR racing told me to gap the plug at .010 because if you didn't the compression would suppress the spark. When we check the jetting the spark plug looks fine. We are going to pull the wiring harness off and do a resistance check and also see if it might be grounding out somewhere.

[akita8]

We pulled the stator cover and found the pulse generator wire rubbing on the flywheel. Did'nt have a chance to try it out but I hope thats the problem.

[section8]

i had a 250r three wheeler do the same thing to me, but mine only did it in first and second. we had a round slide carb on it. i found a newer cr250 flat slide carb and instaled that. it works fine now. i think it was too rich at the top end. try leaning it out. it was like it was loading up real bad and that seemed to fix the problem.