Cylinder bore size to first oversize of .5mm piston/ring combo

[BMANN06]

Hey All,

I've got myself balls deep in a 4tec rebuild (155 4-tec), Yesterday I pulled the pistons out and the rings are proper **Screwed. I need a hone and new pistons and rings. I'm okay with following the assembly instructions of getting the engine put back together but I'm getting a bit confused when it comes to boring cylinder and ring sizing. I'm going to hire out the boring/honing of the cylinders and would like to know how much bore i need them to take off/out to fit the .5mm Oversized Rings Piston combo. Can someone help me out with this?

Many thanks!!!

:cheers:

 

[griz400]

hey guy, first u need to find out what piston sizes are avail for your eng, then u take cylinders to machine shop, they will bore and tell u what size to buy then, then, you will take the pistons to machine shop for them to make the final hone -- if your gonna keep the watercraft, i would suggest the premium parts, if u intend to sell it, then u can go with say middle grade stuff

 

[BMANN06]

Ahh cool thanks griz, Whew i was just going to order the .5mm rings/piston x3, plus all internals for the 4tec from sbt tomorrow. Glad I posted, I'll wait to hear back from machine shop!

 

[Seadoobuddy]

I remember reading in the forum that a regular machine shop may not be the correct place to take them.
You need someone that knows the Seadoo motors. If I remember correctly the cylinder needs to be tapered or something like that.

OK guys, Is this correct?

 

[BMANN06]

Got some good news back from machine shop

Update!

My cylinders are in good shape just need a hone so no need to oversize. Just one new std. piston and new rings for all pistons (I messed up one of the pistons trying to get the rings out). He is going to install pistons and rings for me and I should be able to pick it up early next week.

 

[griz400]

nice, u got off easy after all, now u may hafta flip a coin wether to sell or keep, lol, i would keep till weather is nice, and you will get good money for it........

 

[Seadoobuddy]

BMANN, I take it the motor was from one of your boats...not the ski you bought from Ohio last year..(what's the guys name again???)

 

[BMANN06]

nice, u got off easy after all, now u may hafta flip a coin wether to sell or keep, lol, i would keep till weather is nice, and you will get good money for it........

Hey Griz ... yah i'm pretty stoked to get it back and start assembling it! Thanks again for your help! I'll be definately using it for a bit before I part with it. I've already got a guy that wants to even trade me for a polaris razor side by side. I'm thinking about it! But would prefer the cash!

BMANN, I take it the motor was from one of your boats...not the ski you bought from Ohio last year..(what's the guys name again???)

Hey Seadoobuddy, no I bought a 04' sportster with a motor dissassembled. The previous owner didn't winterize it after some water got in the bottom end. I picked it up cheap to rebuild. My GTI has original motor and is good to go.