TOPIC:

Got ya. I'm just second guessing everything I did now. Hate to have to buy a third set of rings.

Well I picked up a honing tool and put a fresh crosshatch in my cylinders. Definitely took the uglyiness out of the two that were having piston slap, though after I was done I took my bore gauge to it and it does have a slight oval at the top of the cylinders. largest difference is .05mm at the top measurement. Now thats right at what the FSM calls out for a service limit on a stock bore, but in their requirements for a fresh bore they call out a maximum variance of .01mm. What do you think? Have I trashed those two sleeves?

If it was mine I'd bite the bullet and get the next size up piston kit and have the cylinders bored and honed to the next size. You can run what you got but it's not going to last.

How about two .5 over pistons and bore to match?
Steve

I was thinking the least expensive option would be two new sleeves, bore to 74mm and the half piston kit from MTC. with boring the new sleeves it'd be right around 600 smackers. Cylinders 3 and 4 are perfectly round still. Basically redo that half of the jugs.
Problem with boring these sleeves more is they're the stock sleeves and I don't have a whole lot more to work with as far as boring them out. As far as I'm aware to up the size on all four Id need to bore the block for new sleeves then have them bored out to the piston size. 76mm is the next size up from MTC. Now don't get me wrong there's no replacement for displacement. But that'll cost me a little over a grand.
SWest I'm not sure I'm following you. Are you saying find two 74.5mm pistons, and run those in conjunction with the 74mm in 3 and 4? That would probably be the least expensive option if its possible, but at only roughly 150 cost difference I'd probably go the route that keeps all the same size pistons.

Does MTC have .5 over pistons available. It's a common repair on stock motors.
Steve

It's not listed in their catalog anywhere. I'd have to call and find out. they probably have them available under their 'custom pistons' but I'd bet I have to pay an arm and a leg for that.
Even If they do, I'd need a whole set then bore all cyl to 74.5, correct? Or are you saying 74.5 on just cyl 1 and 2 and keep it at 74mm on 3 and 4?

I'd call them and ask. In 78 a wiseco kit was cheaper than OEM so more power and the other parts I needed.
Steve

Hardgun wrote:
It's not listed in their catalog anywhere. I'd have to call and find out. they probably have them available under their 'custom pistons' but I'd bet I have to pay an arm and a leg for that.

Here you can get a 1166 cc Piston kit for 500 Dollar if you don´t want to give your arms and legs away.



www.scheuerlein-motorentechnik.de/motorr...zylinderkopfdichtung

I'll have to do that. Would be nice to have everything perfect again, and gain a little more displacement. Though at .5 over that is the MAX I can bore out these stock sleeves and I've heard rumor of them being a bit brittle and prone to warp at that point. Anyone have much experience with that?
I appreciate the example Scirocco but I'd really prefer to go with a well known and trusted piston maker (not saying those wouldn't work just fine), plus I'd be losing my higher compression with that set. It is an option if it comes down to it. Also can't very the size of the valve reliefs (they look about stock size) so I'd probably have to fly cut those later for the OS valves and higher lift cam that'll be going in which would mean taking the jugs off AGAIN when I get that.
I'll check them out though.

I’ve learned a lot reading over this one. I feel your pain , I hate when things like this happen.

The only oil I used during cylinder installation at the factory was a light coat on the leade, or chamfer at the bottom of the cylinder. After reassembly the bike would go into the dyno room, be run up and down through the gears several times, and then allowed to cool and then re-torqued. I've never heard of greasing a base gasket, but I may give that a try, I'm preparing to reassemble a motor that's been apart on my bench for about 10 years. I'm also debating the one piece/ two piece head gasket choice. Your thread has been very interesting, thanks for sharing your experience and photography skills!