Overheating 900 RMK 2005

[Hjalti_GTO]

I am getting alot of overheating on my 900 rmk 2005 after the summerstorage.
It gets up to 195+ Fahrenheit / 90-100+ Celsius real quick.
Im not loosing any coolant and no bubbles in the tank eather.
Can this be the thermostat or what?

What is the normal Operating temperature on a 900 rmk?
And what is the temperature the thermostat starts to open up in these engines ?

 

[sloan188]

Could be the thermostat; They are common to go.

Any chance the cooling system is airlocked? What are the snow conditions like? If hardpacked you may want to use scratchers. Did you delete the front radiator (Don't think this is the greatest mod for a flatlander).

Thermostat opens at 122 - 145 F (50 - 60 C).

Normal operating temps for mine is usually between 122 F (50C) and 160 F (71 C). I've seen it get up around 200 F and that's when I start getting concerned.

 

[Danbot]

In anything resembling decent snow my 900 ran between 125 and 135 f. Tstats are cheap, throw a new one in and see if it improves.
Also, at 170 f I pull over, shovel snow on the cooler and slides before continuing.... if temps don't start to drop, I stop shut off the engine and let it cool down.

 

[sno_mo_racer]

It would either be a faulty thermostat or air locked in the coolant system. Here is how you can check for air bubbles in system.

1. Allow the cooling system to cool completely.
2. Check the coolant reservoir and make sure it is at the
FULL COLD mark.
3. Place the snowmobile in its normal riding position and
apply the parking brake and run the engine at the specified
idle RPM until the thermostat opens up.
4. Open the bleed screw at the top of the water outlet
5. Cycle the RPM from idle to 3000-4000 so that the coolant
can move around the system and push out the air from the
system.
6. Tighten the bleed screw when coolant starts to come out of
the screw area.
7. Turn off the machine and release the parking brake.
8. Allow the system to cool completely and recheck the
coolant level.

NOTE: It is important that the thermostat stays
open! When the thermostat opens it will draw in cold
coolant from the heat exchangers and the cold
coolant may close the thermostat again. Make sure
the thermostat opens and stays open! Cycle the
RPM from idle to enough RPM (4000) to get coolant
to flow but not enough RPM to engage the clutch.
This allows air to bleed from the rear crossover tube.
It is important to get enough coolant flow to purge
the air from the front close-off cooler and observe
this air reaching the bottle.


If you here bubbles in the coolant bottle then that is the system flushing out the air also. If I remember right can be be also without loosening the bleed screw.

If no bubbles come out after a little while of cycling rpm then it is most likely your thermostat stuck.

 

[Hjalti_GTO]

Thanks for your help guys , I pulled my Thermostat today and i got barely any coolant fluid in the hose. When i boiled the Thermostat it only opend to a 0.2 inches and did it very slow..

 

[94fordguy]

Thermostats are cheap, easy to replace, and very important to the system, be sure to replace with a new one, DO NOT REMOVE and discard the thermostat to run the sled without one, engine damage could occur.

 

[Hjalti_GTO]

Thermostats are cheap, easy to replace, and very important to the system, be sure to replace with a new one, DO NOT REMOVE and discard the thermostat to run the sled without one, engine damage could occur.

I know , it takes 10 days to get new sent here to Iceland, i was just wondering what was the problem while i waited

 

[Blitzkrieg 1]

I had the T-stat go on my 900 Fusion once,it was actually in two pieces when I pulled it out.

 

[05900]

10 days?.......order two you'll probably need them.