2004 600 RMK has no power

[kurto]

About half way through a ride today my 04 600 rmk edge basically lost all power. Had to run full throttle to get it to go about 20 mph. By the time I got it back to the trailer (about 8 miles) it wouldn't even move and sounded like crap. Also was doing a half backfire (or sounded like half a one anyway)

Things done/tried so far.
1. Changed the plugs on the trail = no change
2. 2nd time out this year - cleaned fuel pump/carbs before taken out
3. Has a new slp can and stock pipe - due to tree damage last year. I'm positive it's the right one for the sled. Originally had a slp can & pipe. Maybe jetting wrong now?
4. It was put away with additive in the gas. Added more star tron additive to fuel and topped off with new gas before taking out

First time out it ran fine, went about 20 miles. I know I need to check compression but haven't yet.

My first thought is a fuel problem but just don't know. Guess I should clean the carbs/pump again for starters?

Any suggestions are appreciated

 

[sled_guy]

Check the carbs
Check the exhaust valves and make sure the bellows aren't torn
Check temp sensor, may well be bad. SLP makes a resistor to bypass them. You can't just unplug them.

sled_guy

 

[kurto]

Thanks for the reply.

So far I have cleaned carbs and fuel pump again, looked fine. Checked bellows as suggested and also cleaned VES valves which were very dirty. Also put in a new temp sensor.

Started it up and seemed no change - sounded horrible. Decided to check compression and have about 110 in one cylinder and basically zero in the other (clutch side).

I did have to remove one bolt in the head to get the temp sensor out which was on the same side as bad compression. I did not add any kind of sealant/locktite to it when replaced. Not sure if this made a bad seal which affected compression.

Next I checked the reeds on the effected side and they looked fine. Pulled the head off and everything looks good to me. Or at least good to someone who doesn't have a clue. All seals seemed in tact, etc.

So at this point not sure if my problem was indeed the head bolt not having any sealant, though I wouldn't think this would put my compression as zero.

Not sure where to go from here. Suggestions?! Have some pictures but seems this forum won't allow regular uploads without them being hosted somewhere?

Thanks a ton guys!

 

[kurto]

Another thing, the bad cylinder piston does wiggle maybe 1/16 whereas the other one does not at all. Is this normal?

 

[retiredpop]

Pull the y pipe and have a look at the piston through the exhaust port as you rotate the engine.

 

[cowboy181d]

X2 on pulling the y pipe and checking the pistons. Sounds to me like a broken piston skirt, by any chance did the VES guillotine on that cylinder look like it had made contact with the piston at anytime I know that some of the VES had problems with that happening.... That much movement will cause the piston to rock way way to much.Did the motor seem to have a light piston knock when it ran?

 

[kurto]

Looked through exhaust as suggested. Piston in question was kinda streaky oily looking whereas the other one was fairly shinny and clean. Didn't notice any chips or anything. Not to say there aren't any as you can only see so much of the piston that way.

Is it possible that it is just a matter of crappy rings even though they look fine? Should I take off the other top piece so the pistons can be removed for further inspection?

Thanks!

 

[kurto]

Based on info that I have read I'm inclined to think it is just bad gaskets/seals, especially since the sled only has 1700 miles.

Question is should I replace pistons while I'm at it or is that a waste of money? If so can I just get some aftermarket that fit my particular sled? Are they basically drop and play or do I have to worry about stuff like clearance, etc?

 

[kurto]

X2 on pulling the y pipe and checking the pistons. Sounds to me like a broken piston skirt, by any chance did the VES guillotine on that cylinder look like it had made contact with the piston at anytime I know that some of the VES had problems with that happening.... That much movement will cause the piston to rock way way to much.Did the motor seem to have a light piston knock when it ran?

No, I don't think anything clashed together. Also didn't notice any knocking but it did sound like crap, hard to explain exactly what it was like but not knocking.

 

[cowboy181d]

If you could snap a few pictures of the pistons and cylinders and post them up it would help out. A little cold scoring is normal on a sled motor(usually caused by not giving the sled enough time to warm before taking off) And mic the bores and pistons that will help you determine if it needs pistons and rings. Check to make sure the Bore is good(no galled Nickisil lining) I would guess that you may have just had a bad O-ring on that cylinder Post up a picture of the bottom of the cylinder head so we can see what the dome looks like on the bad cylinder.

 

[kurto]

If you could snap a few pictures of the pistons and cylinders and post them up it would help out. A little cold scoring is normal on a sled motor(usually caused by not giving the sled enough time to warm before taking off) And mic the bores and pistons that will help you determine if it needs pistons and rings. Check to make sure the Bore is good(no galled Nickisil lining) I would guess that you may have just had a bad O-ring on that cylinder Post up a picture of the bottom of the cylinder head so we can see what the dome looks like on the bad cylinder.

Hope these are what you are after. These are mostly of the bad side, thanks.

 

[cowboy181d]

Ok man Judging by your pictures, It looks like it started sucking coolant on the PTO(clutch) cylinder...That kind of cylinder "washing" is caused by one of two things excessive fuel in cylinder or Most likely in this case coolant in the cylinder! I would try putting new cylinder head O-rings in it. Make sure that you add a cap full of 2-stroke oil to the cylinders(to lube the piston/rings) before reassembling the engine. Then compression test it and I bet that it will be back where it should be on compression.

Hope this helps get you back in the POW again Keep us posted!

 

[kurto]

Ok man Judging by your pictures, It looks like it started sucking coolant on the PTO(clutch) cylinder...That kind of cylinder "washing" is caused by one of two things excessive fuel in cylinder or Most likely in this case coolant in the cylinder! I would try putting new cylinder head O-rings in it. Make sure that you add a cap full of 2-stroke oil to the cylinders(to lube the piston/rings) before reassembling the engine. Then compression test it and I bet that it will be back where it should be on compression.

Hope this helps get you back in the POW again Keep us posted!

Thanks for the ideas. I'll give that a try and post back my results.

 

[retiredpop]

I would check out the wiggle you mentioned a bit further as well. Is this throughout the piston travel?

 

[kurto]

Anyone know the torque specs and bolt tightening pattern for the 2004 rmk 600? Can't seem to find it. Thanks.

 

[Jay]

I'd pull that cylinder, you can see the aluminum flecks on the exhaust side of the piston, also looks like some detonation going on to me. If you have no compression on that side and the piston and rings aren't to bad, altho I think they are, then you are losing it somewhere else. Crankseal, base gasket or the ever popular hole in the bottom of the crankcase.