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Powervalve Tool

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I have an 06 YZ125 that I just rebuilt the top end for the first time. In the manual it talks about a special tool you use on the right side to get a push rod apart but I do not have that tool since I bought my bike used. I took the bolt on the right side of the powervalve off, as well as the 3mm allen bolt out but could not figure out how to get the springs off or any further disassembly of the powervalve so just sprayed carb cleaner in there and put the 2 bolts back in.

By doing this did I miss a step that will cause my powervalve to stay open and give me problems? Is there any way I can check this without riding my bike into the high RPMs?

Are there any alternatives for tools I can use to get my powervalve apart or will I need to go to the dealer to buy the tool? My bike started up fine and I just let it idle for 5 minutes for the first heat cycle for break in.

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If you're talking about what I'm thinking of, it's basically a small piece of metal tubing (looks like a suspension bearing bushing) that is you insert between the housing lip and the link. It prevents the assembly from rotating when loosening the bolt.

A deep-well socket of the same size would work just fine.

👍

I have an 06 YZ125 that I just rebuilt the top end for the first time. In the manual it talks about a special tool you use on the right side to get a push rod apart but I do not have that tool since I bought my bike used. I took the bolt on the right side of the powervalve off, as well as the 3mm allen bolt out but could not figure out how to get the springs off or any further disassembly of the powervalve so just sprayed carb cleaner in there and put the 2 bolts back in.

By doing this did I miss a step that will cause my powervalve to stay open and give me problems? Is there any way I can check this without riding my bike into the high RPMs?

Are there any alternatives for tools I can use to get my powervalve apart or will I need to go to the dealer to buy the tool? My bike started up fine and I just let it idle for 5 minutes for the first heat cycle for break in.

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I used a socket to stop the arm from rotating. The previous owner must not have used one and messed up the govenor!

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So what I did was take the right side powervalve cover off, removed the 8mm bolt but then put it back in. I also did the same thing with the 3mm allen bolt in the front powervalve cover. What are the chances that my powervalve is now stuck open?

Before I put the right cover back on, I moved the vertical piece and it did keep springing back into its original place.

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I'm pretty sure the tool you're talking about is a small pin, maybe the size of a #10 screw. It fits between a fork in the link arm and into a hole in the cylinder to prevent the lever from turning the shaft when loosening and tightening the linkage bolt.

Disassembling the PV isn't too hard, but if it moves freely and springs back closed, it's probably OK.

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I'm pretty sure the tool you're talking about is a small pin, maybe the size of a #10 screw. It fits between a fork in the link arm and into a hole in the cylinder to prevent the lever from turning the shaft when loosening and tightening the linkage bolt.

Are you sure?

Mine is a piece of thick-walled pipe/tubing, about as big around as my finger. It came with the 06 YZ125 and is shown in an illustration (drawing, not photo) in the Yamaha manual.

I thought the pin was for the older PV... but I could be wrong. 👍

🤣

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Are you sure?

🤣

I guess I'm not sure🤣. I have an older bike and I failed to read that he was talking about an '06.

The principal is the same, though; prevent the linkage from moving. 👍

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You did not mess anything up. To get the spring off you need to take the cover off on the right side of the bike. The rod the spring is around slides out the right side of the power valve area. The tool they are talking about is the same size as 13 or 14 mm socket so you can use a socket in place of the tool.

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To verify you linkage still is connected you can remove the power valve cover, then start the bike and rev it to see if the arm moves. If it will not move it has jumped from between the two thrust washers on the govenor.

The previous owner of my bike did this and the arm was also broken.

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Thanks for your help guys. I'll try using a socket to hold it next time to get that shaft out.

I tried taking that phillips head screw out of the right side but it was too tight and I was scared of stripping the screw. Will that one need to come out as well?

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I tried taking that phillips head screw out of the right side but it was too tight and I was scared of stripping the screw. Will that one need to come out as well?
Don't think that needs to come out, but if past performance is any indication, don't listen to me 👍

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