250r engine missing when revved up

[Yamatrike400]

My R engine was missing at high rpm with the new pipe( i thought) so i put the stock one back on, still misses. I tried adjusting the plug gap but that made it worse if i opened/closed it more. At first it would only miss with the 36 on it, so i put the 34 on and it was fine for a few days. Today i start it up and go for a ride and now its missing/popping again. What could be the problem? thanks

[Macs]

It could be several things. Did it ever do this before switching pipes? Did this happen as soon as you put on the new pipe? Have you tried replacing the spark plug?

Cutting out at High RPM's sounds like jetting to me. Had this same problem with my Air Fooler. It was 100% stock even the tires so i thought it was extrly odd. Rejetted it, instant fix. That is after i cleaned the carb, replaced plug, air filter etc etc

[Yamatrike400]

It has never done this before except for when i tried a BR9ES plug in it instead of the 8 it had similar symtoms.
When i put on the new pipe, i also had the 34 on it, and it was fine. I tried a 36 just for the hell of it and it cut out at WOT. So i put the 34 back on and it ran great. Now today i go and start it up, go down the street at wot and it i notice it isnt accelerating like normal.

So i went back home and revved it up in neutral to find it was cutting out. First thing suspect is the pipe so i put the stock one back on but it didnt change. I tried messing with the plug and it got worse, now it pops/ sputters anywhere past 1/4 throttle.

I will put in a new plug and see if that helps, thanks.

[Yamatrike400]

I didnt have any new B8es's but i tried some 9's and it did the same thing, i tried cleaning the 8 but that didnt help. Its getting worse everytime i start it up. I wonder if somethings gunna blow lol..

[Macs]

I would try another 8 plug. You had already said that the 9 gave you the same result. then we can work from there. You did alot of changing parts in a short time.

[Yamatrike400]

Took apart the carb, got a B8ES, fired right up, runs PERFECT. Thank you so much man i probably wouldnt have gotten a new plug if you hadnt told me to lol. I can run each gear longer and it runs sooo much smoother. It seems like it Runs better with the stock pipe and answer silencer than it does with the aftermarket one.