Okay, I know this has been beat to death but I need some expert opinions. 87 Lt80 quit running today, so check compression when we got it home and it was only 60psi. So that means another top end rebuild. Pulled it all down and it really does not look all that bad, no scratches or gouges. I used a Wiseco 50.75mm last time and it was a pain in the a@@ to break in. I measured the bore at the top, in 3 places, with my mic and came up with 1.995 inches and both the ring gaps came in over .057 inches so I take it I need to go up to the 1mm over piston. Is there any chance of getting away with a new set of rings and a light hone? I am sure that it would not last as long as a full rebuild, but it would be a quicker fix for now. I run 93 octane with Belray H1R at 32:1(only use this because of my 83 250R). Head has been shaved 20 thousandths also.

 

I would just do it right this time, bore it out to the spec the new piston requires, put it back together right and it should last him/her for a while. If you just fix it fast and cheap you will have to do it again after a while anyway. Thats just my opinion.

 

I think that is what I am leaning towards, but this time I am going with a Zuki Piston. The only problem I have with that is that the local dealers are so high on their parts it is crazy. Anybody have a reliable source for factory parts? Thanks all.

 

rockymountainatv.com is good I think, I have bought from them in the past

 

http://www.rockymountainatv.com/vehicleFilter.do there is the link to the wiseco piston kits, why would you want to try another brand if that one held up for that long?

 

http://www.rockymountainatv.com/productDetail.do 51mm piston kit
http://www.rockymountainatv.co...d=17&prodFamilyId=3146 topend gasket kit

if you spend alittle more.... you get free shipping!

 

The piston kit should be 45 bucks, 10 for gaskets, 40 for a bore.
You should buy a new piston pin, bearing, and cir clips too (11 bucks).
You'll have better luck with the stock zuki piston.
http://www.nrys.com/fiche_select.asp

That's where I get my parts.

 

I had a Wiseco in it but it was not for that long. I do not even think I had it in for a year. I took it to a very reputable motorcycle shop in the area and he got the piston kit and bored the cylinder for me. Had it home a week and it locked up. we let it cool down and I checked everything and it seemed fine and now it is worn out. Less than a year on a topend rebuild with just average riding time, no racing. So this time I think I am going with a zuki piston. Thanks for all the help all.