yz250 powervalve question

Joined
Apr 18, 2007
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#1
my bike's powerband isn't kickin in, and i was told to check out the powervalve,
so i took the cover off n found a loose screw .
when the screw was loose i could push the valve system up and it would go back down when i let go,
when i tightened the screw id move the system up and it stay's up until i push it back down again.

does anyone know what or how it is supposed to be ?

i don't have a book on my bike.

thanks-steve
 
Joined
Apr 1, 2007
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#2
when you tightend up that screw did you make sure that the governor rod was sitting in the powervale drum properly? if you take the screw out and look at the rod you'll notice theres a flat spot in the hole, that has to line up with the flat spot on the drum . if its not lined up it will bind, while your in there it probably wouldnt hurt to clean the powervalve. good luck
 
Joined
Mar 14, 2007
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#3
how clean are the components? if they are gritty parts can get stuck, even break like what just happened to me. hope this helps.
 
Joined
Apr 18, 2007
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#4
WOW, i moved the powervalve to the top from its original placement of the bottum, n tightend the screw , n DAMN THAt HELP, my bike is running sick now,

thanks alot for helpin me out!!!
 
Joined
Apr 18, 2006
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#5
Something doesn't sound right to me.

If I understand what you said correctly you are able to adjust the position of the powervalve and that it is the tension of the nut that holds the linkage in that position.

That sure isn't how my bike works. On my bike there is only one way that the linkage will go together, there is no adjustment. The nut simply holds the linkage together so it doesn't come off.

I am wondering if some previous owner modified the linkage to provide adjustment. The problem with this is that it is a really poor design to have the tension of a nut to keep something under it from rotating. I would expect it to slip at some point and to cause no end of problems.

Unless the power valve shaft was splined so that there were multiple points where it could go on then I predict future problems.

Rod