2017 250xc top end power loss

[Singletrack_rider]

I need some help. Im at a loss. Bike has 35 hours on it now and it feels like its down 5-10 hp in the upper rpm range. Bike was running great at 25 hours and if like someone thru a switch the power was gone. Compression is what it was at 5 hours 190 psi on my gage. I changed main jets up and down in size no difference. To give you an idea of what im talking about i did some comparisons with my 250xcf. In every test the 250xc beat the 250xcf. Now the xcf smokes the xc. The power still feels normal down low and into the mid but anything over let's say 7000 rpm it falls off and feel flat. Nothing chanded on the bike from what i can tell. Temps have are even the same. Could the power valve be sticking and not opening all the way? Could it be an ignition problem. Bike still runs smooth just no power. And yes the air filter is clean, the exhaust is not blocked, main jet not plugged, spark plug changed, fuel is good, compression is good. Help.

 

[M A T R]

Check your stator... maybe the wire is coming in contact with the flywheel.

[lhc450]

Power valve issue would be my guess.

[Singletrack_rider]

It was the power valve. A screw backed out and jammed my power valve. It pulled the threads out so I'm taking it to work and will put a insert in tomorrow. 

[M A T R]

Thats kinda scary...

[Singletrack_rider]

9 minutes ago, MountAiryTrailRiders said:

Thats kinda scary...

You're telling me. I think i rode an entire enduro like that. The few times i got on it the power felt flat. Now i know what a modern 250 feels like without working power valves. It feels like my 1982 IT250.

[BushPig]

18 minutes ago, GreenMT_Rider said:

You're telling me. I think i rode an entire enduro like that. The few times i got on it the power felt flat. Now i know what a modern 250 feels like without working power valves. It feels like my 1982 IT250.

I missed the link arm on my 150 once lowering the jug on. It was non operational in the "open" position.

bog... bog...nothing.... bog.... nothing.....piping...bog....piping... 38hp right off a jump face. It was the second time I rode it, so for a second I was worried a 150 was so pipey,

[theBIGnaud]

This seems to be a reoccurring thing..

[lhc450]

It was the power valve. A screw backed out and jammed my power valve. It pulled the threads out so I'm taking it to work and will put a insert in tomorrow. 

No Bueno[emoji15]

[Singletrack_rider]

All back together and running great. Luckily nothing else seemed to have gotten damaged. 

[sandking11]

That's a really common issue. I've seen it on loads of older 250 and 300's  , might just pop to the garage to loctite mine.......