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why does this powervalve arm thing keep bending?

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a friend took his bike apart to do a top end, and his powervalve arm looked bent he said.  put it together, and a ring caught a port within 5 engine hours.  ruined the cylinder.

 

so we got a used cylinder online... and the powervalve arm thing is bent again?? why does this happen to these crs?  

 

IMG_1891.jpg

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I have a whole motor in pierces I got off a guy that was doing a cr500 conversion. When I was checking everything out I noticed the same thing, bent PV foot. I assumed it was because everything was loose in the box and it hit something.
They both seem to have a circular punch mark on the same part which kinda makes me think it wasn't lined up properly before the cylinder was installed so when the nuts were tightened it pushed on the centre of the opposing shaft from the motor.

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Yes Braplife88 is correct, not the best picture but shows something. when you have the cylinder on the base you must rotate the power valve linkage on the cylinder to line it up with the governor linkage on the base. If not, it will bend the "crows foot". Seen this happen many times. 

IMG_0514.PNG

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Weird. I figured that's what happened by looking at the punch marks and to be honest. It did that to me the first time I attempted to put the cylinder on. I caught it early enough and corrected it, but it seems like this one bites a lot of people in the ass. It was super obvious when it happened and an easy fix. Interesting. I bent the foot back straight. Hope she holds!

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Not sure, have only done one top end on my bike and have yet to have any type of failure. the manual calls for that part to be lubricated so I always go by the book, hopefully someone can chime in here who knows. IMO I would grease it though as the top end removal only take around 35 minutes and could be way faster than having to fix any possible damage it may cause.              

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