I was doing some night riding this weekend when the air temp was -20 to -30F and was really surprised that my temperature warning light came on a few time. I installed a rear tunnel cooler over the summer with the hopes of never seeing that light again! The engine is stock and I was using 92 octane gas and the coolant level is spot on. I am wondering if something weird happens when it is that cold out that the snow doesn't cool as well or get kicked up onto the coolers as easily? I would have thought that the air temp alone would have been enough to keep it from overheating... I was just doing some moderate speed (20 to 40 mph) trail riding when the light would come on. The trails were groomed and pretty hard, but there seemed to be an acceptable amount of loose stuff on the surface. Any ideas would be appreciated.
Jasonw
New member
Sounds like you need some snow scrappers to throw some snow on your heat exchangers. Mine overheated last year at -20c on hard packed trails. You can also try some water wetter than can really help dissapate heat in your cooling system. It's all on here if you do a search.
Jetting is not enough for the cold temperatures...
rx1jim
New member
It is possible that the trails you were riding were so hard at those temps that there was very little snow being churned up and thrown onto the heat exchangers. If that is true, then a set of ice scratchers would help. Does it overheat when riding at warmer temps with looser snow?
Thats what i was thinking. running lean cuz of temp?Whammy said:Jetting is not enough for the cold temperatures...
09nytro
New member
sounds like thermostat my wife rides one she overheated this weekend checked thermostat wasnt opening all the way so it doest close bypass so it doest go to heatexchangers so coolant just runs though motor 

02ViperMtn
Member
probably a dumb question, but is the coolant mixed 50/50 with water?
My bet goes for the thermostat
i was riding the srx with the digital temp guage and i never seen over 135 degrees and it was -6 degrees ...
Thanks for the suggestions. When I added the rear cooler over the summer, I drained all of the coolant and replaced with fresh Yamacool (dealer said it is premixed). This was the first time I had it out since then, so I don't know how it works in different conditions. Is there an easy way to check the thermostat for proper function? I was also thinking about adding a water temp gauge... where is the best location to put the temp probe?
bigreis said:Thanks for the suggestions. When I added the rear cooler over the summer, I drained all of the coolant and replaced with fresh Yamacool (dealer said it is premixed). This was the first time I had it out since then, so I don't know how it works in different conditions. Is there an easy way to check the thermostat for proper function? I was also thinking about adding a water temp gauge... where is the best location to put the temp probe?
You might have an air lock in the system. Try bleeding the system again.
09nytro
New member
the way you do it is get a cup of water to 122f to 130f (the thermostat is only 50c) then set it in the water it should open 1/4 to 1/2 more than it was closed . the heat exchanger is just giving you more cooling 
