yzf600r to a 660

anyone heard of this on here they did it to the fzr600 more than the yzf but im going to have it apart and am going to do it but havent found out if it can be done to be reliable

 

I'm not sure how much response you'll get about that question here. The YZF is two-whole generations past the XJ. Heck, we barely talk about the FJ series here.
There are dedicated YZF forums out there which might have people who have practical experience boring that engine out.

 

ya i didnt think i would but the off chance i figured was worth it and ya i have looked on those but everyone who has done one seems to have disappeared from the groups so idk how they did long term wise

 

What year ? Wiseco do oversize kits but 637cc is the biggest they go

 

no im stroking the motor not boring. and they used to do oversize kits but they dont anymore sadly

 

Wiseco will do anything if you are willing to pay them for it. Not that I'm suggesting you do. Tooling and setup costs would eat you alive unless you find enough people who want the same kit.

 

What crank do they use ? because unless there is a drop in crank with a stroke that suits you'd be looking a serious amount of money to do that compared to a rebore and bigger pistons

Never mind found this http://fzronline.com/forum/viewtopic.php?f=30&t=1199 which shows both ways of doing it but for a YZF looks like a lot of work for little gain

 

i talked to them and they said talk to their sister compny je they told me it would be about 800 to get custom pistons made to and bore over for the bike and any compression. but with a bore over its close to 1000 to get the aluminium cylinders replated. thats why im going with a crank that has a longer throw

 

i spent 40 on a crank and rods for it and i have heard of people gaining 15 to 20 hp out of it