Super Jet Getting some new sleeves for a new member :]

[Sablabra]

Hi.

im new to this forum and this is my first post :]

I bought last summer my first jet, a yamaha superjet 95 mod hull with a 61X cylinder and a 62T case.

The engine is heavily tuned, with a billed machined head, duble 44mm blackjacks, custom made drypipe exhaust, cusom cooling system and lots more. At the end of the summer, the engine was running poorly and i desided to rebuild it.

I opend it to see that it got wiseco pistons messuring 82,5mm, and sleeves messuring 88mmOD.

So ill be buying some new wiseco pistons for it in the same size, but im unshure about the sleeves, if i need some special kind, to cope with my heavily modded engine, or where to find sleeves in the same size.

Anyone got some recomendations to what sleeves i shud get, and where to buy them?

Thanks!

 

[Sablabra]

So the block and sleeve is stock size?

Is it worth boring up the block and drop in a bigger sleeve?

Sorry for inactivety, been working on some other project.

 

[JetManiac]

Why dont you just bore it one size up and keep the same sleeves?

 

[Sablabra]

i think the sleeves allready have been bore up, whats the min wall thickness in the sleeves? But if thats possible then ill rather do that.

 

[Matt_E]

Sounds like you're at 82.5mm now. You can bore up to 83mm, 84mm, 84.25mm, and POSSIBLY 84.5mm.

 

[Sablabra]

I have the sleeves removed from the engine now, so ill get them machined in a lathe. Whats the piston clearance? i have read 0.08mm (0.003") is that correct?

 

[#ZERO]

That will never work... you have to bore the sleeves out while they're still in the cylinder.

You'll need to find a machine shop near by that has the proper equipment such as boring bar and hone machine.

If you're running raise compression with a b-pipe the recommended clearance with cast pistons is around .0045" and .0055" with forged pistons.

 

[Cross]

You dont remove the sleeves to bore them. Piston clearance depends on what type of pistons you have (forged vs Cast).

 

[Sablabra]

Ok, thanks for pointing that out for me. The old pistons were wiseco, and i dont see any reason why to not use wiseco again, so i guess ill be using forged.