Fouling Issues - 2012 600 Pro

[Troutfrea]

Good morning everyone,

I recently bought a 2012 Pro 600 w/ 155 track for my teenage daughters to ride. Outfitting the entire family with sleds without breaking the bank has proven to be difficult! ? Anyway, the sled had 2400 miles on it when bought but seemed to be in really good shape and I didn't notice any issues. I'd estimate we have put 50-75 miles on it this winter. At first she seemed to be running fine, but is suddenly fouling the exhaust side plug like nobody's business. Here are some thoughts and additional intel:

- This seems to be happening every 10 miles or so. It will get progressively worse and after stopping, I will need to baby the throttle to get it to start (while pulling on the starter cord). I shut the sled down for the weekend once it was obvious I had a problem but I still needed to get it back to the trailer.

- After initial research, I thought maybe it was because I didn't let it warm up enough (running rough, electronics flickering, etc.), but it seems to continue fouling plugs even when warm and on the trail.

- The plugs look dark grey/black - like they have excessive carbon buildup on them. I can post pics if it will help.

- I am currently running the non-ethanol resistor but AM running ethanol free 91 octane. I haven't switched because I wanted to ensure I had ran all of the "old" gas out of the tank prior to going to the ethanol free resistor. Could this be causing the problem? If I try the ethanol free resistor, what are the chances the fouled plugs go away?

- Does starting and stopping too much lead to a fouled plug problem? I've never had an issue like this with my other sleds, so my gut says no, but its worth asking.

- Other threads point to a TPS issue and I will check that out. Is there an easy way to do? I did find this video, and it's seems manageable but am wondering if there are any other tricks?

- I plan on inspecting everything tonight when I get time and am hopeful I find something obvious but am not counting on it. I've seen plug wires mentioned. Is there anything else I should be on the lookout for? Maybe a bad coil, something going on with the throttle body? Any tests I can run? Any and all help is truly appreciated.

- PS - this machine doesn't seem to be using much oil in my opinion. Like I've mentioned above, I estimate we've put 50-75 miles on the sled and my oil reservoir still seems almost full to me. Could lack of oil be contributing to this problem?

 

[Troutfrea]

Greetings, I have an update and need opinions and advice. I pulled the power exhaust valves and the Mag side was excessively dirty. The sludge was so bad that I could not pull the valve off of the motor. I literally had to pry it off and it took way more force than it should have. I couldn’t believe it. Some pictures are attached. The PTO side was dirty but came out like it should have.

So I’m wondering if I have an underlying problem and too much oil is being delivered to that cylinder. Or was the valve just so dirty that it couldn’t open all of the way and problem compounded on itself and this is the result? What would you all do? Cleaning and give it a test run or look for an underlying issue?

Also how in the heck do I clean the inside of the block? Do I worry about that? Run it hard once it’s back together and hope it burns off? Thank you in advance.

 

[davesilb]

Clean everything up the best you can by wipeing and using carbon cleaner or something that will help with the cleaning. DO NOT USE WIRE BRUSH OR ABARISVE material to clean the valves. Are you using the right type of 2 stoke oil or maybe mixed oil that is not compatible? Look at your oil in oil tank and make sure it looks okay and not jelling. Then change your resistor as you are now running too rich with any non ethanol fuel in the tank. Then give it a try again. Have you taken a compression test? Is one hole low on compression?

 

[davesilb]

Be sure the hole from the cylinder up to the power valve bellows is clear and not plugged. I spray wd-40 down the hole to make sure it is clear and clean

 

[MARV1]

Use carb and brake cleaner for the valves, possibly one was stuck open causing plugs to foul.
Run Champion RN57YCC plugs and it’ll run way better NGK’s were crap on that engine.

 

[Troutfrea]

Thank you both for the replies. I have cleaned up the valves and will put it back together as soon as i can get new gaskets. I found some 50 miles away but that’s better than waiting for them to be shipped to me a week from now.

I definitely think the mag side valve was stuck. When I tried removing it, the thing was so gummed up that it would not come out. I had to pry it out! Fingers crossed a good cleaning resolves the issue.

I’m running Polaris VES full synthetic. I suppose the guy that owned it prior to me could have ran something different but I know he took good care of the machine and the oil looks perfect in the tank. The PTO side seems to be operating fine so I don’t think oil is an issue.

My biggest concern is cleaning the cylinder head up. It’s a mess. I will do my best but I probably shouldn’t spray chemicals/cleaners into the cylinder area right? Maybe carb cleaner is okay? Dave are you saying to spray WD-40 down the hole that is in the cylinder wall (where it meets up with the power valve)?

The tip on the plugs is interesting. I hadn’t thought of running a champion plug. When I bought it, I put fresh fresh NKG BPR9ES plugs in it. Again, the PTO side seems fine.

Once I have everything together I will try to run the sled and hope that it burns off whatever excess crap this issue has caused. Hopefully the problem doesn’t persist.

Thanks again for the replies, Chad

 

[Troutfrea]

Well I think I’m screwed. Cleaned everything up nicely, put it back together, grabbed champion plugs as suggested, and decided to grab a compression tester while I was at the store. Sure enough no compression. The mag side which was giving me issues only has 45 pounds, the PTO side has 90. Looks like a rebuild is now upon me. ?

What’s interesting is I decided to fire it up anyway for a minute. She started beautifully on the second pull, ran at 1350 RPMs for a minute or two and then started sputtering out and eventually died. Anyway, onto figuring out how to rebuild this thing.