07 800r. Crashed the sled so I started to tear it apart and I had the nun off and looked up threw the y pipe. Both pistons had major scratches. So I pulled off the top end(they barely give you enough room to do this). Both pistons just on the the exhaust side are hammered. Is this a common thing on the 07? Its odd they looked like this cause my last ride the sled ripped.. Also is it best to go stock doo pistons, wiseco or rktechs dual ring? I can get wiseco for the cheapest but I wonder if the dual ring is worth it. Also who sells caged bearings for this sled?
800r pistons...exahust side
- Thread starter NEWDUCK
- Start date
M
mxracer328
ACCOUNT CLOSED
i bought a whole set from mcb performance, and they seem to be holding up well, comes with caged bearings, and all gaskets. they are also a dual ring piston.
seems like they make a good priced kit. Also does the bigger wrist pin mean I have the updated enigne? Or is it the other way around
Crank!
Has your motor be updated with a new crank case? Before you put your top end back on check your crank runout and crank bearings, I replaced the nun on my 07 this last fall and happen to look up into the clylinders and my piston on the pto side was scuffed up @ the exhaust port. I thought it was from a cold start or something like that, about 75 miles later it siezed up and it turns out that my one of my crank bearings was going out..I got lucky my buddy caught the bearing noise as we started putting the top end back together. Ski-doo paid 75% of the short block and I paid 25% plus labor to put it back together. It cost about $1100.00 to fix. I hope this isn't your problem and you just scuffed you pistons and that's it but it would be worth checking since the motor is apart.
Has your motor be updated with a new crank case? Before you put your top end back on check your crank runout and crank bearings, I replaced the nun on my 07 this last fall and happen to look up into the clylinders and my piston on the pto side was scuffed up @ the exhaust port. I thought it was from a cold start or something like that, about 75 miles later it siezed up and it turns out that my one of my crank bearings was going out..I got lucky my buddy caught the bearing noise as we started putting the top end back together. Ski-doo paid 75% of the short block and I paid 25% plus labor to put it back together. It cost about $1100.00 to fix. I hope this isn't your problem and you just scuffed you pistons and that's it but it would be worth checking since the motor is apart.
I would definitely use a 2 ring Piston. I just did a compression test a couple hours ago after the install of Big Johns Dual ring Piston and what a huge gain in compression. I added RKtek's Head last season.
Stock - 125#
Stock w/RKT 14.1 Head - 135#
Sledhead Racing Piston and RKT Head - 150#
Can't wait to try it out.
Stock - 125#
Stock w/RKT 14.1 Head - 135#
Sledhead Racing Piston and RKT Head - 150#
Can't wait to try it out.
i would bank on the crank bearings being part of the problem, i thought mine was just a scored piston also untill i tore the engine the rest of the way down. inside bearing on the mag side was gone. welcome new short block engine. hope this one lasts longer than the first one
I checked my run out at the start of the season, it was .0025. So your saying crank shat was what scored your pistons? I would think if a bearing was falling apart id see material ontop of the piston also
i never thought my crank was bad, could not feel anything turning it over by hand. was not going to spend the money on the top end without checking everything good. and i was very surprized to find the bad bearing. worked at cat/yamaha dealer for 7 years and never seen anything like this.
roughly how many miles were your sleds at? mines at 1450 and talking to frank may ski doo today he said he thought if I had a bad crank it would of gone by now. Not saying it wont go but who knows.
miles
Mine went out at @ 1000 miles, I've heard of many 800r motors going out in between 300 to 2000 miles, no one's safe just lucky to get past 2000 miles. IMO. When my sled was apart their was no indication of a bad bearing (metal wise) but you could hear it or feel it but with the right tools you could.
Mine went out at @ 1000 miles, I've heard of many 800r motors going out in between 300 to 2000 miles, no one's safe just lucky to get past 2000 miles. IMO. When my sled was apart their was no indication of a bad bearing (metal wise) but you could hear it or feel it but with the right tools you could.
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F
FNG
Active member
RK Tech pistons have a shorter deck height and are specific to his high compression head design. I would check with him first if you are considering using RKT pistons without going to his head. It may be ok but Kelsey told me to not use any other pistons but his with his head (which I have) as Wisecos and others "would not work" with his head and I am guessing it is due to the shorter deck height, maybe works the other way too I don't really know but check with him about your application.
Ditto on the MCB dual ring kit, mine runs great. Compression ? What can I say, I now call it "Thumper".
