RMK 800 overheat

[Jlager]

Was out riding two up yesterday and spent the whole day on a cat track, never getting into any deep snow. About 30 mins into the ride I noticed the sled was kind of bogging down a bit. Saw that the temp light was on and immediately stopped and shut it off. Found coolant shooting out of the top of the tank.

I let it cool down so no more coolant was coming out and threw snow on radiator to cool that down. As I had lost a lot of coolant, I filled it up with water, just so I could ride it home. Not sure if this was a good idea or not but I didn't have any temperature issues going back.

I plan to take it to a mechanic to have the coolant flushed but why did it overheat in the first place? I was riding two-up and on a cat track (which I have done many times before with no overheating issues) but it still had quite a bit of loose snow chunks on it which I thought would've been sufficient for cooling. I wasn't using my ice scratchers as it didn't seem necessary but maybe I should have.

I also noticed the rear snow flap keeps getting pulled into the track which probably isn't helping with this issue. I'm not sure how much the flap is part of the cooling process.

Is it possible I did any damage to the sled when it overheated?

 

[WyoRMK]

Check your thermostat. I had the Thermostat on my old 03 800RMK lock shut causing the sled to do the same thing.

Easy test is to throw it in some hot/ near boiling water and watch it open!

 

[maddog21]

check for the belt on water pump, it might broken.

 

[Leardriver]

Broken water pump belt?

When it is running and warmed up, can you see coolant swirling around in the coolant fill bottle?

 

[Jlager]

Broken water pump belt?

When it is running and warmed up, can you see coolant swirling around in the coolant fill bottle?

I can't remember looking at the coolant fill bottle with it running after putting in water to fill it up. It did ride just fine without any temp issues for about 30 mins after that which is what it took me to get back to the car.

I'm guessing if the belt was broken, I would have issues going back too? I did put down the ice scratchers going home though and it was downhill the whole way so maybe that made the difference.

 

[bigdan743]

more than likely the overheating was because of the snowflap mispositioned, wouldn't let snow to the coolers. but now the antifreeze is diluted and needs to be flushed out and refilled for proper strength and make sure flap stays where it is suppose. no snow on the coolers means overheating

 

[Andreas83]

Its the snowflap, the same thing happened to me last time i was out riding.
My koso egt/water temp started flashing, the flap was caught by the track.
Bendt it back in place and temp was down half a minute later.

 

[Vincenthdfan]

My girlfriends Edge did this last time we were out riding in very icy trail conditions.

I was convinced her water pump belt had broken and since that same belt also drives the oil pump I didnt want to chance an engine seizure.

We towed it all the way back to the trailer and tore it apart once home...pulled recoil cover and found belt was fine.

We suspect low snow conditions, icy trail, uphill climb, and no ice scratchers.

Lessons learned?

Install ice scratchers first and foremost.

If you suspect a broken belt, I discovered if you pull the two 8mm bolts from the oil pump, swing the pump outta the way, give the rope a quick tug (with the kill switch off of course).

You should see the slotted end that engages the oil pump drive on the end of the waterpump shaft turning.

If that slots not turning, your belt is broken...DO NOT RUN YOUR MOTOR...its not getting any oil if that belts broke and will seize.

 

[theultrarider]

Yep, suck the flap in on an edge chassis, and it will over heat almost every time. You are blocking off the heat exchanger from getting any cold snow to it.

 

[Andreas83]

Mine got hot even with a the big van amburg cooler i have installed.
So with a stock cooler it must get hot really quick.
There is no way you would have been able to ride back home if the water pump belt is broken.
There is a plastic piece behind the snowflap, over time it gets bent towards the track.
Try drilling out the rivets and turn it the other way around.

 

[Jlager]

Thanks for all the replies. I'm going to guess it was likely the flap that did it then. Read about using a blowdryer to heat it up and bend it back. How far can I bend it back before it stops doing its job off throwing snow back onto the track?

 

[oredigger]

My buddies 800 is doing the same thing. He has a long piece of truck mud flap bolted on as a snow flap. There is no rigidity to it at all. Would this have anything to do with the overheat? Not letting snow catch on the cooler?

 

[beeler]

Pawder Wump Belt

Check your Pawder Wump Belt.

 

[oredigger]

What a brainiac. Just what we need on here, more dip****s.

 

[hipockets]

What year 800? If it is a 02-05, change the thermostat to #7052267. It will block off the bypass when open, forcing all coolant to circulate through the coolers. Also, depending on the year, there are some changes that could be made to the coolant hose routing to give better cooling.

 

[Jlager]

What year 800? If it is a 02-05, change the thermostat to #7052267. It will block off the bypass when open, forcing all coolant to circulate through the coolers. Also, depending on the year, there are some changes that could be made to the coolant hose routing to give better cooling.

It's an 02. So I had it overheat again a couple weeks ago and this time I lost pretty much all my coolant. Luckily, my mechanic happened to be riding in the same area as me and stopped to help. What's weird is that neither the running boards or heat exchanger in the back got hot when it overheated which suggested the thermostat was sticking closed.

Mechanic just took the thermostat out and said to just run without it since it's so mild where we ride and just let it warm up a bit before I let it rip when I take off for the day. The thermostat visually looked fine though he said. He suspected it's either because we were simply going too slow on the cat track up (riding two-up) and not getting enough snow on the heat exchanger, or that the thermostat was sticking or both.

Either way, I've been running without the thermostat for two weekends in a row now without issue but it has also snowed a lot so I haven't been riding hardpack cattracks very much. So who knows but so far so good.

 

[hipockets]

The stat which blocks the bypass will let it run even cooler as no coolant will circulate only in the engine when it is open. Also, remove the tee connector between the head outlet and running board rail cooler. Put a straight connector in. Remove the hose which goes from this tee to the front tunnel cooler, and plug the outlet on the cooler. This will force all coolant to run through the entire system. It does not make sense why the factory has it set-up to allow some coolant to run the short circuit from the engine to the front tunnel cooler, and back to the bottle. Also when putting the stat in, have the "bridge" of the stat aligned with the housing bolts.