PRO RMK mid range bog/plug fouling Clutch side

FernieHawk

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So a buddy and myself head out Tuesday afternoon to catch the fresh pow in the Fernie area, it was approximately -5 degrees at 3400 ft. A few kilometers into the ride I catch a rock on my M1000 and trash the A-arms. We head back to the trailer to grab my other buddies 2012 800 Pro Rmk which has had six trouble free rides. The buddy I am riding with also has a brand new 2012 800 Pro Rmk with only two rides on it, also trouble free. All of our machines were filled at the same gas station.

So I start the Pro and let it warm up to around 85 degrees before moving it out of the trailer, after moving it from the trailer and it warms up to around 95 degrees it starts to lose RPM’s and eventually stalls. It wouldn’t start without a little throttle, and it wouldn’t idle without a little throttle. We take off down the trail thinking it will clear up soon…nope…mid range BOG. Bwwwwaaaahhhhhh…. Bwwwwaaaahhhhhh….. Bwwwwaaaahhhhhh, then at half throttle it starts to rip, right up to 8200-8400, then back to Bwwwwaaaahhhhhh…. Bwwwwwaaaahhhhhh….. Bwwwwaaaahhhhhh at low throttle inputs. Pull over and it dies. Check plugs and both appear fouled with a glossy black color.

Swapped the plugs (GR9A-EG) from the other PRO and she starts right up and runs normally for about 3 or 4 Km and then back to the same old crap. Swap the resistor from premium to ethanol…same thing happens. Back to the trailer and swap plugs again.

Next day I pick up some BPR9 EIX Iridium plugs and then fire up the sled from cold with the fouled plugs in it, it starts and idles normally and the it does the same thing, after it warms up to around 90 degrees it starts to lose RPM’s and eventually stalls. Put the new plugs in and it runs good for a kilometer and then starts the mid range bog thing, wont idle and wont start without a little throttle input. Now with the brand new plugs it looks like the fouling is limited to the clutch side, Mag side looks good. Back home to read four hours of forum info.

Today I picked up some BPR9ES plugs (no GR9A-EG in town) and went and tried one more time. Did not over rev it, kept an eye on the throttle safety switch…blah, blah, blah. It did the exact same thing as the day before. Starts on the first pull with the ORIGINAL fouled plugs and after warming a bit, it stalls. Put in new plugs and it runs for a bit and then starts the mid range bog and idle problems. Checked the plugs again and the Clutch side is fouled, black and glossy, the Mag side looks fine. Running temp was 122-125 degrees.

I have attached some pics of the BPR9ES plugs. Sorry for the long story, but the owner of the sled is out East right now, there is no local dealer nearby and I was hoping to clear this up before he gets back so we can go riding. Anyone have any ideas?
 

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  • Plugs - Mag on Left - Clutch on right.jpg
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Luvinit

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You could try swapping plug wires around or with another Pro to see if you have a bad one, possibly check the exhaust valve operation to see if bellows/ports are ok, I,d check compression.
 

FernieHawk

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I'll check into the wire swap and compression test. Don't think I will start messing with his power valves, I'll leave that for the shop...not my sled.

Thanks for the input
 

FernieHawk

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Looks like it was water/ice in the TPS connector. Thawed the machine out, took off the connector and a lot of water was present. Blew out the water with compressed air and now the machine runs fine. It would start and idle normally when the water in the connector was frozen, but as soon as the ice melted when the engine was around 90 degrees the engine would stall.
 
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