The lowdown....
86 TRX250R motor w/ 300 kit
39 PWK carb
Boyessen Reeds
89 Long rod with spacer plate
Shaved Head
Paul Turner Hi Rev pipe
PVL digital ignition
Stock porting

Bike runs great at idle, but has no ***** when you give it gas. It breaks up at high end. It did this with both the stock and PVL ignitions. Has anyone had this problem? Are the ports out of whack? The bike was sleeved for a 300 kit. Please help if you can.

 

Did you check your jetting... sound like the main and maybe needle position could use some adjustment.

 

does it break up at 1/2 throttle at all rpms?

does it break up at 3/4 throttle at all rpms?

does it break up at full throttle at all rpms

have you checked the plug? if fouled it will act somewhat like you are saying. remember just because it is a new plug doesn't mean its not fouled.

check plug gap, it should be around .026-.028

check the plug wire cap

 

I've tried new plugs, new ignition, different carbs, etc..that's what puzzling me. I have a couple 250R's and have all of them very modified. I've tried different jets, everything that I can possible think of. I don't get it...

 

have you checked the compression?
It sounds like ignition or the carb.
you still have not explained how the bike is acting at different throttle positions compared to engine loads and rpm's.
What mains are you running in the carb, I have a 267 (.110 over) and run 190 main jets but I know some one with a .090 over motor running only 172 for a main jet. Mine has a much more radical port timeing though.
The only other thing I can think of is since you have another 250r swap the jugs and heads and leave everything else the same except for maybe a main jet so you don,t burn down

 

I know this sounds simple and the others were giving you great advice, BUT how are is your sparkplug gapped? When you raise the compression(shaved head), you also raise the possibility of blowing out the spark. Try closing up the gap to .025 or even less. I learned this trick from the MacDizzy web site. If you've never checked it out, all two stroke nuts should. www.macdizzy.com

 

My '86 had the same problem. It is a weak stator. Try this, Narrow the gap on the spark plug and go get a NGK B8EV. The "V" plug has a thinner center electrode so it will get the spark to jump a little easier. Also take off your stator cover and get a wire brush to clean off the rust off the flywheel to help the spark. A new stator is only about $200 so you aren't that out of luck. Hope this helps,

CT250R....1986 CT310R & 1988 CT270R

 

Last time I checked a new stator from Honda was $486.00 Rickey Stator has rebuilt ones for about that price.

Have you checked your reeds. The plug gap is a good idea too.

 

I got my brand new stator from Honda for 189 dollars last July.

 

Interesting. Well...I have to stop by the Honda dealer and pick up parts for customers, and I'll have them pull it up again.

I had one go bad when the flywheel broke and trashed it. The dealer quoted me $486. The boys might have some answering to do...Wonder if there is a difference in years, this was for my old '86.