Best way to go ?

[Freakrider]

Yamaha 760 currently 85mm (max bore) rear cylinder slightly scored from air leak/lean condition, I have the entire motor apart down to bare cases..machine shop guy looked at it and says just hone it "anything left on cylinders won't amount to a hill of beans". Three options : #1) I was thinking of going with 85mm wiseco pistons or pro-x... hone both and put it together.#2) I would try to buy some used cylinders at 84mm and bore them.#3) buy some new sleeves and I have a friend who can put them in.(but hear that oem sleeves are the hardest/long lasting) I plan to use all new oem gaskets/crank seals. Thanks for your opinions.

 

[WaveDemon]

why not bore it to 85.5? I run 86mm pro-x pistons on a stock sleeved 760 cylinder. it works great!

 

[Freakrider]

why not bore it to 85.5? I run 86mm pro-x pistons on a stock sleeved 760 cylinder. it works great!

quote from Group K: "you must understand that the 760 cylinder has only two bore oversizes...that is .010" and .020". The base sleeve of the stock 753 cylinder is not thick enough to safely sustain any larger size pistons. In the event that the cylinder wall was significantly damaged, the sleeves (or cylinder itself) would have to be replaced." Also Riva racing catalog for 85.5/86mm wiseco/pro-x pistons says "requires re-sleeving" How long has this worked for you and any other guys reading this know about max bore on 760 ?

 

[marz831]

I know Tim has been running this setup for quite a while with no issues.