Yamaha Dirt Bikes Forum

The bottom is a lot more complicated you want the manual and a very clean and organized place to work.  

Bill H. 2000 CR250R

listen to bill.

you will need some special tools as well, flywheel puller (dont even think of prying off that flywheel!!)case splitting and reinstalling tools. a press makes it easier to put the cases together, but the installer tools are probably safer for a first timer. go to rockymountain.com type in your bike info and go to tools. most of the tools will work on many machines so its a good investment.  

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06yz125,kx60(2)

When I tore the motor everything measured out to be in spec so all I did was replace the cylinder and piston, now that its back together it would like to bog when I was breaking it in only when going uphill and it still likes to bog uphills and when I give it full throttle.

Also the previous owner never ran a filter and when I took apart the air box the entire thing was covered in sand and mud !  

just as I suspected the power valve linkage is not moving thus not opening, I did a quick search online for a new governor and I had no luck in finding anything..

does anyone here know where to get these parts or is it a dealer only thing  

i think the marks on the from using something sharp to take it off.  
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'05 yz125
go blue and you'll need a wheel chair

the governor will be dealer only, search e-bay for used parts, make sure your linkage is installed properly and the powervalve itself moves freely with the linkage disconnected.

keep in mind the powervalve needs engine rpm to force the governor to move the linkqage.  

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06yz125,kx60(2)

the power valve moves fine w/o the linkage connected however I am unsure if the linkage is connected properly, all that is connected is the linkage and then the bolt to hold everything together... With it setup like this the linkage can slide back and forth on the power valve and sometimes will bind up on the edges of the bolt..

Should there be any washers or anything in there aside from the linkage?  

I found this on another forum:

"And to the threadstarter, I have the same year YZ mine just isn't a WR. These powervalves are incredibly easy to install and uninstall there's nothing to em. On the left side of the powervalve there will be a punch mark that goes up. And check the stop for any wear, and any wear on the face of the powervalve. These stops can wear out causing the valve to rotate too far and rub the piston. Everything else goes back on pretty easy, it can really only go on one way. Make sure when you torque the bolt that goes through the powervalve you stick a punch in the hole and the the little notch on the piece thats attatched to the actuator rod. This keeps the rod from moving and you wont break it again."

and I also found this picture:


My linkage has no stop or anything like in the picture however when I got to bikebandit and look at their exploded diagrams, I cant even tell where the linkage is and it doesn't look like there is supposed to be a stop.

If anyone can help me out with a picture or diagram showing what pieces I may or may not be missing that would be fantastic.  

Also my "PUSH ROD ASSY" (#2) just slides out of the case as if the "GOVERNOR FORK" (#4) isn't bolted down at all.

http://www.bikebandit.com/assets/schematics/Yamaha/YA-3JD1010-9020.gif  

I got two little bolts to connect the push rod to the governor fork and the power valve still doesn't move when I rev it and watch, when I had the cover off it looked like the gear, springs and bearings were in good shape..

also when I'm revving it up I can see puffs of exhaust come through where the power valve linkage connects to the power valve  

have you tried taken the system apart. they may just be jammed from carbon build up which is an happens often to neglected powervalves. the rpm's do no push the powervalve open, i always thought it was the air being pushed out the engine that opended the them.  
______________________________
Ride 2 strokes, buy 2 strokes, save the 2 stroke.

1998 cr125
2002 cr80

its directly rpm related though. the higher the rpm the more air is being pushed by. so your right. yeah. i'd take everything out and clean it, and double check that it goes in exactly as the book says. ~pat  
PEACE GUYS ITS BEEN A BLAST!!!!! ~patrick

The cylinder and power valve assembly is all brand new, my only guess is that the governor springs were messed up by there not being a governor fork to push against..  

power valve governor operation is based ONLY on engine rpm nothing else, period.
attach your linkage using the guide pin (a thin rod that matches the notch in the linkage to a hole in the head) then tighten the lock bolt.
leave the cover off and reinstall the exhaust.
warm up the engine and rev it up by snapping the throttle quickly. you should be able to watch the linkage move as the rpm goes up and down. you have alread determined that your power valve is clean and moves freely with the linkage off.
if you have no movement, disconnect the linkage and retest. if the linkage moves, your power valve is binding. if it does not the governor and or linkage is dammaged. and you will need to remove the right engine cover to inspect.

update us after following these instructions  

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06yz125,kx60(2)

pull the side cover and make sure the governor fork is in the proper position on the governor assy.
sorry i didnt pay more attention to the earlier posts.  

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06yz125,kx60(2)