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2012 PRO RMK running horrible

1
Jan 3, 2019
3
0
1
So I bought a 2012 pro rmk 800. Has slp stage 4 kit on it. Every since I had it the sled would bog when WOT from a dead stop or would bog when WOT in general. Changed fuel filter and it did not work. I Was riding in the UP this past weekend and got the sled stuck. When I tried to start it again the pull cord would not move. Tried turning the clutch by hand and clutch was getting stuck after a couple turns each way. Finally got clutch to spin freely and when I started the sled it was running horribly. Almost like it was on one cylinder. Took out spark plugs because I thought it was flooded and the plug on the mag side looked like it was hit by piston. The gapping was way off. Rode it to nearest road to pick up sled and sled kept bogging at all speeds and rpm. The check engine light did not come on at all. Not sure if its not getting fuel or what it is. Need help ASAP to get this figured out. Everything I read so far there is countless things that could be wrong. Thanks.
 

BILTIT

Well-known member
Premium Member
Apr 9, 2011
1,682
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Lloydminster, SK
Sounds like a rebuild is needed. Check compression if you can or just pull head. Look in exhaust port will tell you a few things also.


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1
Jan 3, 2019
3
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Tested compression. 30psi in mag side cylinder. Took apart motor to find out I'm missing multiple chunks from my piston and cylinder. One of the chunks from cylinder being over a inch long. Me and all my buddies cannot even fathom how this could have happened. Sled was running at perfect temp. Oil light was never on. No check engine light. Piston just decided to let go. The long rod motor from Indy Specialties was supposed to fix the famous "piston slap" issue on the polaris 800 motor. Anyone have any ideas how this happened?
 

BILTIT

Well-known member
Premium Member
Apr 9, 2011
1,682
482
83
45
Lloydminster, SK
Any pics? Might not have anything to do with motor, could very well be fuel system related.

Might be motor related too, either way i would get ahold of indy specialties and see what dan has to say.

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AKDoug

Well-known member
Lifetime Membership
Jan 27, 2009
82
65
18
How many miles on it ? 1500 miles is about tops on a 2012 RMK 800. Many went down sooner.
 

srt20

Well-known member
Lifetime Membership
Oct 25, 2010
130
46
28
Mine ran perfect as well. Then the crank ventilated the bottom case. Then it didnt run so well anymore.





Hey it happens.
 
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