Loss of top end power....

[AceYZ250]

OK me and a buddy was riding the other day. bike was running good. Then we started jumping a little bit. Never get into the powerband for oh about half an hour. Small jumps. LOL. So we got done than headed home. Well it was like I had no power valve in the bike at all. Powerband was totally flat. The motor wasnt winding out like it should at all. Its not the plug Ive already checked it out. Any Ideas would be great. Thanks all.

[AKColby]

Is this a YZ250?

[schwen_108]

Maybe you need a new top end?

[AKColby]

Originally Posted by schwen_108

Maybe you need a new top end?

Yeah, you may want to do a compression test, I don't know what kind of PSI you should be looking for though?

[AceYZ250]

My Bad yes its a yz250. Yeha I will do that tomorow.

[hardlydangerous]

When was the last time you removed and cleaned the power valves?

They may be carbon or gummed up and not working
A simple compression test will tell you if the top end is in need of replacing or not

[RICHIE500]

Originally Posted by AceYZ250

Never get into the powerband for oh about half an hour.

Why not?

I would say you either need the top end done or maybe your Power valve is probally stuck in the closed position...maybe?

[AKColby]

I'm thinking it's your topend, either way you're going to take the cylinder off, I'm willing to bet thats the problem.....

[AceYZ250]

I didnt get into the powerband because I didnt need to. I think it is the power valve. Not sure though. I havent had time to tear into it yet. Hopefully this weekend. Thanks Guys.