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powervalve hit piston
Posted: 07:04 pm Mar 27 2015
by argclh6670
Hey guys, i pulled the topend on my kids bike 95 200 to replace after about 150 hrs. Noticed that at some point the PV made contact with piston. What causes this? Pv worn? Bike was running well still. Stock bore. Will add pics soon.
Re: powervalve hit piston
Posted: 10:31 pm Mar 27 2015
by diymirage
shouldn't be possible unless the barrel has been bored and an oversized piston installed (which you mentioned wasn't the case)
I cant think of any scenario that would cause this to happed
did you by chance measure the piston or did you go by the markings on it?
Re: powervalve hit piston
Posted: 11:07 pm Mar 27 2015
by argclh6670
diymirage wrote:shouldn't be possible unless the barrel has been bored and an oversized piston installed (which you mentioned wasn't the case)
I cant think of any scenario that would cause this to happed
did you by chance measure the piston or did you go by the markings on it?
I measured it. Piston measures 66.
It doesnt make any sense to me either. Does or can the pv wear enough to seat further into its bore?
Re: powervalve hit piston
Posted: 02:12 pm Mar 28 2015
by Jaguar
on m y '89 200 it was impossible for the piston to hit the powervalve.
Did it damage the rings?
Re: powervalve hit piston
Posted: 03:10 pm Mar 28 2015
by bufftester
66 is stock bore, so can't see how the PV contacted the piston. Would have made a mess of things if it did. Pics?
Re: powervalve hit piston
Posted: 06:47 pm Mar 28 2015
by argclh6670
bufftester wrote:66 is stock bore, so can't see how the PV contacted the piston. Would have made a mess of things if it did. Pics?
As you guys can see, it barely grazed it. bike was still running good and was holding 165 psi compression.
im just wondering why this happened. it also looks as if it had happened awhile ago due to the carbon buildup on contact point. im planning on putting a new topend and taking abit off the pv with a dremel.
