Loss of power - suspect power valve
 

Wondering if anyone has any ideas before I pull the bike apart.

I have a 2008 ec300, out yesterday and whilst climbing a steep hill with the power valve operating fine the bike experienced a loss in power at the mid to top end of the rev range all of a sudden. Since then the bike starts fine and revs freely until the point when the power valve comes in but then becomes flat and won't accelerate to the limit.

My suspicion is the power valve mechanism. Has anyone experienced this before I pull it apart?

Cheers

Not a common problem but it has happened just like on other 2strokes. Pull the right side PV cover, it should be obvious.

Ok mate thanks

When my 02 XC250 was brand new it seemed to lack power.
I took the PV cover off to find that the linkage was never connected
from the factory! Lucky for me the nut did not drop thru the linkage hole
into the bottom end. Hooked it up and WOW what a change in power!
Good Luck!

power valve
 

My power valve was not working all season. Bike ran well, no real surprises. I only discovered it this winter while taking parts off to clean. Seems the small bolt snapped off the plate and just floated up and down pretending to work but never actually attached at the cylinder side. Since this is my first real 2T dirt bike I had no idea until my buddy said, it seemed to lack power. This year will be a lot different. Yeah!