09 600 cylinder pictures from idling after rebuilt top end

[SaskRMK]

I just replaced my top end after i noticed the compression just dipped below 100. I had a leaky oil pump earlier in the season but I replaced it before anything happened so this was probably the culprit of the loss in compression. I had rode another 1000 miles after I replaced the pump on the same cylinders and pistons.

I swapped out my cylinders for fresh ones from CV tech and also installed SPI Pistons. After bringing the sled up to temp in my garage twice after the rebuild I decided to tear into it again to ensure nothing bad was happening.
(It only takes me 30-40 minutes to tear a top end off these sleds) My PTO cylinder was perfect and the non PTO side looked like this.

Does this look normal? the rings appeared to have little brown spots on the outside. I re-assembled the sled, took it out with a tank of mixed fuel for break it and rode it for 5 hours under 7000 rpm with no issues.

Just looking for some opinions on that cylinder, It has zero miles just a start up and brought to temp. Everything was covered in VES gold during assembly

Thanks for looking

 

[m8magicandmystery]

so is the compression close to each other..??...if the marks can not be felt..??..i think if you have the mixed gas...good break-in and patient warm-ups you just may be ok..


what do you have to lose now..??...do you think the rings could still snag a port..??

 

[slash]

looks like it was not real clean ,I put mine in the dishwasher and run cascade
it gets them scrubbed up real nice with water hotter than our hands can stand

 

[SaskRMK]

Its running fine right now i just wanted opinions on that cylinder since the PTO side did not have these marks after idling the sled.

I was just a little surprised to see these marks after the sled was running for less than 5 minutes. A friend just dissasembled his 600 EDGE XC with 13k miles after his crank snapped and his cylinders that have 5k miles were still perfect.

You could not feel the marks. They were Clean reman cylinders right out of the sealed box and bag from Cvtech.

 

[m8magicandmystery]

They were Clean reman cylinders right out of the sealed box and bag from Cvtech.

you can not trust them to be clean..for the installer to clean them is the "last line of defense"...lol..

 

[sled_guy]

Did you check piston ring end gap? Not normal on a fresh rebuild. Ring installed wrong on the pistons, ring gap too tight, not enough oil on startup... something.

But if you can't feel them you are fine running it... unless it is ring end gap and then when you get it good and hot you will likely stick a ring.

sled_guy

 

[SaskRMK]

I have rode the sled 60km at half throttle with no issues right up to 125 temp. Cylinders and rings were covered in oil during assembly and i poured a caps worth on top and turned the crank before installing the head. The Ring gap was measured before assembly. Compression is 110 in each hole.

 

[SaskRMK]

UPDATE

well things cant be going that bad I have 124 PSI in each hole after a full tank of mixed fuel for break in