Viper Mountain ( 2004 ) Running Hot... ?

Lasse

Lasse

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Joined
Mar 6, 2005
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551
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SWEDEN
Hi !

My friend have some over heating problems with his Viper Mountain ( 2004 ).
He is stricktly using it as a trail sled to 100%,
always driving it at moderate speeds.
The problem is that it running hot and the temp light comes on all the time.

Anyone have any ideas how to get it to run cooler ??


:2strokes:
 
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One thing I would start with is make sure you have bled the rear heat exchanger. On vipers the manual calls for bleeding the rear and the front. But from my experience the rear heat exchanger is the only one that matters. Lift the rear of the sled up about 5" off the ground, take the coolant reservoir cap off, remove the round black rubber plug from the tunnel extension and you will see a screw under where the rubber plug use to be. You want to open the screw but be ready to tighten it right down again. When you unscrew the screw you should have coolant come out. Once it comes out tighten the screw back down. It is a little messy so have some rage around. After you do this put the machine back on the ground. Fill the reservoir with coolant to the cold line. Then see if it's still overheating.


Another possibility may be a bad thermostat. You can pull this off and test it by heating up some water in a pot with the thermostat in it. See what temperature it opens up at. Should open between 48 to 52 C.

Lastly it could be a bad coolant pump. To check that you pretty much have to pull the exhaust off, drain the coolant, then remover the waterpump cover. Then try to spin the water pump impeller. If it doesn't spin that is good. If it spins freely, then that is bad. If it spins freely the gear driving it may be bad or if you're lucky it could be the threads holding the impeller bolt on are stripped.

Hope that helps. I would start by bleeding it then check the thermostat. Work easy to Hard.
 
if your coolant system checks out and your friend is still running the 2" track, you may consider the addition of ice scratchers if your mainly riding hard packed trails.
 
snowdad4 said:
If he still running the 2" track,
you may consider the addition of ice scratchers if your mainly riding hard packed trails.
Click to expand...
Yes , the sled have ice scratchers.
 
Check coolant as stated above, ice scratchers must be down, and what are moderate speeds? I have seen lots of sleds overheat when moving too slow.
 
Newbee said:
1. The thing I would start with is make sure you have bled the rear heat exchanger.
2. Bad thermostat.
Should open between 48 to 52 C.
3. Bad coolant pump.
Click to expand...
Tonight me and my friend did some work on the sled,
everything went well!
1. Checked and ok.
2. Checked and ok.
3. Checked and ok.

grapeape said:
What are moderate trail speeds ?
I have seen lots of sleds overheat when moving too slow.
Click to expand...
Most usually between 50-100 km/h

:2strokes:
 
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A few other thoughts to look into:

If you haven't mixed the coolant with water you will loose cooling ability. So if your coolant is 100% coolant with no water then that is bad and you'll need to probably change out the coolant. I believe if replacing the coolant you want a non-silicate based coolant.

Another thing I would think about is do you have any leaks? You may have a leak but not know it. So you may want to pressure check the system. Someone else will have to chime in on the best way to do this since I have an idea but I've never actually done it.

Along the same lines as the pressure check I would make sure your reservoir cap is sealing.

And another idea is testing for a bad temp switch. Unless you know it's actually overheating. Hopefully someone can chime in on this one also since I've never tested this either. I'm sure there a resistance value for it. If you have another viper or srx or mountain max maybe you could swap to see if you still get the light.
 
From what i have seen with vipers, 50kmh is getting into the danger zone in regards to the sled being able to throw enough snow to cool it. Also, scratcher placement should be at the bend of the rail, if its half way to the rear, its only throwing snow in the air.
 
I've seen something as simple as no snow flap cause heating issues...lets too much of the snow "escape" out the back instead of catching it. It does have one, right?
 
Newbee said:
If you haven't mixed the coolant with water you will loose cooling ability.
So if your coolant is 100% coolant with no water then that is bad and you'll need to probably change out the coolant.
I believe if replacing the coolant you want a non-silicate based coolant.
Click to expand...
The antifreeze is mixed 50/50 % with water and is of the non-silicate type.

grapeape said:
Scratcher placement should be at the bend of the rail
Click to expand...
OK , checked !

mod-it said:
Does the sled have a snow flap ?
Click to expand...
Yes , the Yammi OEM snow flap.
 
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u could get an infrared temp. gun and take readings at different spots in cooling system and compare to a similar sled if possible. there is a margin of error with them depending on the level of quality. or if no other similar sleds see if the temp of head area is obviously high. cant really tell ya what would be considered a reading in the danger zone though. like newbee suggested could be a faulty temp sensor.
 
Did you raise the needles half a notch?
Also, are you holding constant throttle? That builds up heat.
 
Any luck sorting this out? I have the same sled, trail riding, same problems. I spoke with previous owner and he said he never had overheating probs on trails.
 
Being a mountain viper I believe it should have a rear heat exchanger is that correct?

Also did you check to see if the coolant is circulating?
 
Newbee said:
1. Being a Viper Mountain,
I believe it should have a rear heat exchanger is that correct ?
2. Did you check to see if the coolant is circulating ?
Click to expand...
1. Yes.
2. Yes, the coolant is circulating.
 
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