96 Summit 670 Rings frozen

I am a newbie to snomachines but of mechanical mind (I built my harley from scratch)...this is also my first post on your forum...

I just purchased a 96 summit 670 and the motor was frozen up. Machine has 802 miles on it and had not been started for 8 years. The motor was not fogged and it looks like no prep work for storage was performed.

I got her unstuck by putting some oil and wd in the jugs...I hand cranked it for a day without plugs to loosen things up. Primed the jug and put a gallon of 50:1 fuel/oil in the tank. Compression was still at 60psi on the hand starter side - 130psi on the clutch side...not good... Put a new plug on and verified spark...after a few cranks she hit and started but was lugging hard...after about 20 seconds she clanked and stopped hard. Rather than risk a broken crank (which may still have happened) I pulled the head and that piston is smoked and needs replaced.

It appears without measurement that the cylinder wall is scored about .005" deep - obviously need new piston rings and maybe a bore....

I have never worked on 2 cycle motors before...so - I am guessing that I should pull the motor and verify no pieces fell into the bottom end but my real question is can I just hone it out and put a new piston and rings in her and run it? Can I buy .005 over rings? What kind of piston slap is too much with a cast piston?

If I overbore that jug must I do both? Makes sense to do both but how bullet proof are the cranks?

What should I do to the bottom end while I am in there inspecting for pieces? Seals and check the oiler pump? Regrease the end caps?

I need dependable..I don't care so much about power right now. We go in 50 miles into the middle of Alaska and I need to have a machine that is dependable.

The other machine I bought with it is a 96 grand touring with 742 miles - I got it running really good - starts first pull at least in the garage...

I picked up the 2 sleds with a covered aluminum trailer for 2800. I don't want to put much money into the 670 at least not more than needed to make it dependable.

thanks for your time...

Randy

thanks

Thanks for the input.

Can I split the case without pullin the clutch? I don't have the pullers for it.

The rods are in like new shape....

I only plan to replace one piston unless I bore it then I will do both.

The rotary valve got bent up and scored a circle about .008-.012 deep into the crank case - I bought a used 87 model on ebay pretty reasonable - hoping that it will fit my 86 components.

I will resurface the rotary housing and replace the rotary valve.

Can I repack the seals or should I just put new ones in? I don't have the case apart yet, but the insides of the motor that I can see look like new - hashmarks from honing are still in the cylinders etc.

Anything special to separating the cases? I will pull off the rotor and stator....hoping to not pull the clutch.

rebuild

I ended up having a shop in WY re-build me a different motor. My case ended up being shot and the replacement turned out to be a 700 triple (anyone need one???).

Going to start putting the rebuilt motor in tonight....hope it goes well.

Termination dust settled on the mountains yesterday - moose season is over and my bear is in the freezer...time to ride the sno-go's soon!

not going to happen

Builder sent me the wrong year motor. I have a 1998 Summit X 670 HO motor....

More schooling for me.....trying to make it work with my original 1996 flywheel, stator, carbs, HAC etc.....

Cross your fingers for me!

Snow is getting further down the mountains......