2018-04-04 YZ250 full throttle sputter

Nice little rip on the 250 today. It's been awhile! New piston and main powervalve. Weird bog at full throttle though, left me 🤔 🤔 🤔 Plugged main jet, or dirt on flywheel, timing is off, powervalve sticking, or bad crank seal, or what ?

[@GodfatherMaxi]

new sparkplug , clean the carburetor ,
and check everything and reed valve.

[@jesseison-bowman3964]

You need to raise the needle up out of the needle jet until it starts to bog then go back one click on the needle. Then increase main jet size until it bugs then go back down one main jet size. Jetting is absolutely critical

[@Quinton_treecutter]

I’ve got a brand new carb, adjusted my valves and I don’t know what the problem is

[@jesseison-bowman3964]

It will rev out each gear stronger and longer once you fatten up jetting too

[@didmonster]

So I just picked up an old KTM that has some hesitation on the top end of the gear any idea of what it could be?

[@ShyMoney244]

Did you ever find out what it was

[@sayebzebbi2774]

Hey. So what was it ?

[@MrGoPro44]

Would love to know the problem here, having same issues

[@capsitan]

sounds like a lean bog, not getting enough fuel at higher rpm, check your main jet and carb settings, compression?

[@gittyupalice96]

I got the same issue on a very very low hour bike. I'm gonna look at it again tomorrow, but I think it might be the float height is too low. Because on my bike I can go wide open throttle and it does it fine for a second or two, then its a hard shut off like fuel is 100% cut if I let off the throttle the bike will instantly come back and run fine again until I go full throttle. I'll update this comment if I remember.

[@Quinton_treecutter]

gittyupalice96 have you tried yet?

[@gittyupalice96]

@@Quinton_treecutter the float height was at factory spec (17mm) on my Keihin carb. I found the brand new spark plug I put in had turned pure white in just a few miles of riding, so I ordered larger main jets to try along with shimming the needle jet. That should solve it for my case any way. (waiting on UPS)

[@rideordie2736]

@@gittyupalice96 did you solve issue on your bike

[@gittyupalice96]

@@rideordie2736 Yes lol, actually about two weeks ago. Its an enduro bike, so because of the street legal stuff the clutch lever has a switch on it, the kick stand has to be up to de-activate the clutch lever kill switch, so I pulled the wires out and soldered them together, problem solved bike no longer cuts out at high rpm.

[@jesseison-bowman3964]

Stuck top end if you dont richen up that jetting

[@devangarcia3119]

That bikes engine is prolly blown already 😂😂😂

[@MattEllermets]

Actually, I'm still riding same bike. 8th year now.

[@devangarcia3119]

Matt Ellermets dam

[@devangarcia3119]

Matt Ellermets usually 2strokes blow when I ride them in the woods idk lol maybe ya just a better rider

[@MattEllermets]

Lots of maintenance to keep them going. But yeah probably over 400 hours on that bike now

[@ianmcgill9954]

Ever figure it out?

[@devangarcia3119]

Never get a 2stroke if your gonna ride it in the woods

[@onlysnaps69]

thats literally the dumbest think ive ever heard

[@sekacity3425]

@@onlysnaps69 yup.

[@Em2Ron]

Yeah try that on a 4 stroke even worse. 2 strokes run cooler because of oil in the gas.