Replacing Piston Ring

[yzinger]

Hi all,

Just wondering if it is possible to replace the piston ring without taking the piston out of the engine? Bike is a 1985 YZ80N. I mean, is it as simple as removing the 4 nuts at the top of the head and sliding the barrel and head off in one go, and then swapping the old ring for a new one? Or do you have to take the head off seperately, barrel off, then piston out to replace the ring?

Bike still runs fine, just seems a little bit low on compression when kicking over and is sometimes hard to start, it could benefit from a new ring right?

Thanks in advance.

YZinger.

[500Fool]

If there's room to lift high enough there's no reason you have to take the head off. Usually with rings they should be replaced before you start to lose compression, by then it's normally too late. If the bore's worn and the pistons slapping about then new rings aren't going to help much. Maybe a rebore might make it a bit tighter?

[Doc]

don't forget to drop the coolant before you start or it could end up somewhere it shouldn't be..like in the crank and/or all over the floor

[Freakshow]

screw that just ride it for another 3 years then sell it to some other peanut , like nathan    he was looking for that model i reackon, and in 3 years hell forget this post by then 

[Doc]

sell it to some other peanut like nathan

Nathan may forget the yz re-ring topic but I figure he'll probably remember the little comment above

[Freakshow]

im just counting the moments till he turns up, i still cant believe i havent reelled im in yet,  he must be in deep water somewhere il have to cast a little farther, maybe in another topic?  he has to surface soon :O)

[yzinger]

Thanks guys, the reason I was asking is that I just bought a new standard size ring for $10, and was thinking of replacing it. But maybee the compression isn't that bad, i'm used to kicking big 4 strokes over, and the bike still runs fine. If I do have a crack at it i'll take your advice and drop the coolant, and as for being enough room, I might take the motor out and put it on the bench. But as freakshow said I'll probably keep riding it for the meantime, the power band has some sting in it for an 80.

[Freakshow]

go the freak you know you love him :O)