2018 Mountain Cat M800 Overheating

[JGrover]

I have a 2018 Artic Cat Mountain Cat M800 duel rail that is having overheating issues and wanted to see what others have done to fix this issue. The sled will overheat on trails and in powder. I've had it overheat in deep powder multiple times. When this happens in the powder, it will take a couple of cool-offs before it stays at normal temp for the remainder of the day. I could run multiple days with no issues and then it pops back up. It's pretty sporadic. It is frustrating when I run with a lot of friends who have Alphas with no flap and their sleds have no issues other than normal overheating.

I have always run with a flap even though I want to remove it.
I run scratches on trails no matter what.
I changed out the thermostat last fall and did see a little improvement. I can't remember if I put in the 2020 model thermostat or the original 2018 OEM thermostat. I think it is the newer one. ( I know the new opens at a lower temp)
Put new coolant.
I have checked for air bubbles.


I was thinking of just removing the thermostat completely. I know this would take the sled longer to heat up. ( It already takes longer than many sleds to warm up)

Any thoughts on this would be great.

 

[DonKiddic]

I chased a very similar issue with a 2020 alpha the entire first year. What I found was the skid plate wasn’t fastened good the entire way around the belly where the cooler was and certain conditions it would catch enough snow and ice over the cooler completely and for that would cause it to overheat a ton. Rode it for 3 seasons after with zero issues.


Sent from my iPhone using Tapatalk

 

[akdanno]

I had a similar problem on my 23 mountain cat. It was water inside the wiring harness, specifically at the plug for the temp sensor. I pulled all the plugs on the machine and packed them with dielectric grease, problem instantly solved

 

[JGrover]

I chased a very similar issue with a 2020 alpha the entire first year. What I found was the skid plate wasn’t fastened good the entire way around the belly where the cooler was and certain conditions it would catch enough snow and ice over the cooler completely and for that would cause it to overheat a ton. Rode it for 3 seasons after with zero issues.


Sent from my iPhone using Tapatalk

Ill look into this. thanks for the reply.

 

[JGrover]

I had a similar problem on my 23 mountain cat. It was water inside the wiring harness, specifically at the plug for the temp sensor. I pulled all the plugs on the machine and packed them with dielectric grease, problem instantly solved

Ill look into this and see if it is the fix I need. Thanks for your reply.

 

[boondocker97]

Had the same thing happen on my 2014 big bore after doing a top end. Changed thermostat and burped coolant several times. Plumbed in a fuel pressure regulator to the line with a gauge up by the handlebar and found the fuel pressure would drop intermittently. Tested voltage to the pump and it was low. Ohmed the stator and it tested bad. Was basically running the sled a little lean. Especially in deep snow at WOT. So if you don't find anything else check your fuel supply.

 

[akdanno]

I pulled the flap off mine on day one. If you have coolant and no mechanical issues, you should never overheat in deep snow

 

[jarred kale]

I have a 2018 Artic Cat Mountain Cat M800 duel rail that is having overheating issues and wanted to see what others have done to fix this issue. The sled will overheat on trails and in powder. I've had it overheat in deep powder multiple times. When 192.168.100.1 192.168.1.1 this happens in the powder, it will take a couple of cool-offs before it stays at normal temp for the remainder of the day. I could run multiple days with no issues and then it pops back up. It's pretty sporadic. It is frustrating when I run with a lot of friends who have Alphas with no flap and their sleds have no issues other than normal overheating.

I have always run with a flap even though I want to remove it.
I run scratches on trails no matter what.
I changed out the thermostat last fall and did see a little improvement. I can't remember if I put in the 2020 model thermostat or the original 2018 OEM thermostat. I think it is the newer one. ( I know the new opens at a lower temp)
Put new coolant.
I have checked for air bubbles.


I was thinking of just removing the thermostat completely. I know this would take the sled longer to heat up. ( It already takes longer than many sleds to warm up)

Any thoughts on this would be great.

what coolant do you actually use ?

 

[Old & slow]

I have a 2018 Artic Cat Mountain Cat M800 duel rail that is having overheating issues and wanted to see what others have done to fix this issue. The sled will overheat on trails and in powder. I've had it overheat in deep powder multiple times. When this happens in the powder, it will take a couple of cool-offs before it stays at normal temp for the remainder of the day. I could run multiple days with no issues and then it pops back up. It's pretty sporadic. It is frustrating when I run with a lot of friends who have Alphas with no flap and their sleds have no issues other than normal overheating.

I have always run with a flap even though I want to remove it.
I run scratches on trails no matter what.
I changed out the thermostat last fall and did see a little improvement. I can't remember if I put in the 2020 model thermostat or the original 2018 OEM thermostat. I think it is the newer one. ( I know the new opens at a lower temp)
Put new coolant.
I have checked for air bubbles.


I was thinking of just removing the thermostat completely. I know this would take the sled longer to heat up. ( It already takes longer than many sleds to warm up)

Any thoughts on this would be great.

First off AC has a excellent cooling system and you should not be having these problems. I would not recommend removing the T stat and running it. There is a possibility of a cold seizure when doing this and pistons and cylinders are expensive. Did you elevate the front of your sled a foot or so when adding coolant this will help with air removal. Scratchers on the trail are a must with the 3 inch tracks. Checking electrical connections are a good thing to do just for routine maintenance. Also inspect the wiring harness for rub through or damage. The coolant temp sender can also be checked for resistance with a multi meter. Go to Country Cat and they have service manuals available on line you will find a chart with the specs. If you are still having issues I would first confirm that the engine is actually hot a temp gun works good for troubleshooting. If it is still overheating I would go back to the t stat remove it and test it. I don't think its the water pump as most mechanical issues are either it works or it doesn't. Good luck and keep us updated!

 

[JGrover]

what coolant do you actually use ?

Arctic Cat 2436-871 Extended Life Anti-Freeze 60 40 Mix​

 

[JGrover]

First off AC has a excellent cooling system and you should not be having these problems. I would not recommend removing the T stat and running it. There is a possibility of a cold seizure when doing this and pistons and cylinders are expensive. Did you elevate the front of your sled a foot or so when adding coolant this will help with air removal. Scratchers on the trail are a must with the 3 inch tracks. Checking electrical connections are a good thing to do just for routine maintenance. Also inspect the wiring harness for rub through or damage. The coolant temp sender can also be checked for resistance with a multi meter. Go to Country Cat and they have service manuals available on line you will find a chart with the specs. If you are still having issues I would first confirm that the engine is actually hot a temp gun works good for troubleshooting. If it is still overheating I would go back to the t stat remove it and test it. I don't think its the water pump as most mechanical issues are either it works or it doesn't. Good luck and keep us updated!

Ill start going through all of this. Thanks for the suggestions.

 

[Ol* Geezer]

My sled and 2 others in our group have had this problem. I replaced the heat exchanger with the longer one from a Cross Country sled and completely solved all my heating problems.

 

[bnorth]

My 19 started running hot under normal conditions on the trail but stayed cool in powder so I changed the t-stat and it runs normal temps now.
IIRC there was an issue with some of the 18/19s and the impeller slipping on the water pump shaft at higher RPM. That could be your issue.

 

[line8]

Coolant level?
Fill it all the way up


Sent from my iPad using Tapatalk

 

[Aw9]

I was having intermittent overheating issues on my 2019 m8000. Sometimes sled was fine, other times it would overheat constantly. I changed thermostat to the new part number and installed a new SP1 radiator cap( like 1/2 price of cat). Coolant filled to just below filler neck. No issues since.

 

[JGrover]

I was having intermittent overheating issues on my 2019 m8000. Sometimes sled was fine, other times it would overheat constantly. I changed thermostat to the new part number and installed a new SP1 radiator cap( like 1/2 price of cat). Coolant filled to just below filler neck. No issues since.

Thanks for the suggestion! I will look into the radiator cap.

 

[JGrover]

Coolant level?
Fill it all the way up


Sent from my iPad using Tapatalk

Yeah, it is all the way full.

 

[JGrover]

My 19 started running hot under normal conditions on the trail but stayed cool in powder so I changed the t-stat and it runs normal temps now.
IIRC there was an issue with some of the 18/19s and the impeller slipping on the water pump shaft at higher RPM. That could be your issue.

Thanks for the suggestion. I will check on the impeller.

 

[JGrover]

My sled and 2 others in our group have had this problem. I replaced the heat exchanger with the longer one from a Cross Country sled and completely solved all my heating problems.

This may be what I try next. Thanks for the suggestion.

 

[ratandalez]

I changed out the thermostat last fall and did see a little improvement. I can't remember if I put in the 2020 model thermostat or the original 2018 OEM thermostat. I think it is the newer one. ( I know the new opens at a lower temp)