1989 Yamaha 250 issues

rjgabrielli

Member
Jan 6, 2008
2
0
I just recently installed a new power valve and assembly on my 1989 YZ 250. Before installing I noticed that when I would try to get up and go in 1st and 3rd gears it would bogg down and act really "Jumpy" when I pull down on the Throttle. I took the power valve cover off and noticed it was broken and missing a few parts (Boss Lever, etc.). After installing the new parts and being careful to do it correctly I got the same result.

I'm not too sure where else to look or how else I can really explain what the bike is doing... It starts completely fine and sounds great. It's only when I put the bike in gear and go (in 1st and 3rd gears) that I experience the problem.

Would anyone know what would be my next step? Or where else I would look to get this problem resolved. I'd appreciate any help as I'd like to get my riding season started.

Thanks again,

Robert
 

rmc_olderthandirt

~SPONSOR~
Apr 18, 2006
1,533
8
What happened that the parts were broken / missing?

Did you verify that the power valve was operating properly when you put it back together? You can leave the cover off the linkage area and then watch the power valve rotate as you rev it up (in neutral).

It is possible that by not operating for however long the parts were missing that the power valve has become stuck. It is also possible that parts down in the governor are also damaged.

If the power valve operates okay then I would recommend going through the jetting exercise. Do a search to find out more about that.

Rod
 
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