Polaris ATV Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter · #1 ·
My 1992 Polaris trail boss liquid cooled 350l is running hot after 15 min. Every time I ride it. * Water is churning from water pump nicely..... No air in system, *really, everything with the cooling system would apear to be in good working order.... *BUT.... * My cooling fan only comes on when it's at it's boiling point, so I wired it to be on with the key on..... *Even with the fan running all the time it still gets hot..... * If I fill the radiator with water and go ride till it gets hot, shut it down, cool it off and head home, when I take the radiator cap off the water level always drops to or under the top passage holes.... * *So that would tell me it's leaking coolant right? *But where? *The system doesn't appear to have ANY leaks what so ever... I should mention that I tried to pull the wire off the thermister to test it and the male connector broke off ruining the thermister...... But like I said I wired fan to run constant so that should be fine right? * I'm stuck and could really use some help....... *ANYTHING will help...... I am mechanically inclined and almost always figure out my own problems..... But I'm past that point now.....* Thanks
-Josh
 

·
Premium Member
Joined
·
20,001 Posts
Welcome to the board!:star:
 

·
Registered
Joined
·
2 Posts
running hot

well I am going thou the same thing when I got my 95 sport 400...it would run great for 15-30 with no problem then start to lose power,so I have done top end on it now three x..but still keeps blowing head gasgets,so I have pulled apart the outside cases and found the problem,my gears for the water pump and main gears are tost,now I am tring to get the counter balance out so I can replace..the atv is not with doing it to,but I am on a mission now...mine looked like it was working right too,because the water would move enough when I opened the rad. cap off..I hope this will help..but I hope you do have the same problem as mine..It looks like it will be alot of time and $$$..good luck
 

·
Registered
Joined
·
4,081 Posts
OK a couple things about a cooling system.
They operate above the boiling point. They accomplish this by NOT running just water, but at least a 50/50 water Glycol mix. Also it is pressurized. Both of these things allow it to cool and maintain a appropriate temp at temps to almost 240 degrees. Now if your running too much water that 240 number will be lowered depending on how much water. I suggest a flush and refill with 40/60 or 50/50 water to Glycol mix. THEN replace your radiator cap! This little cap maintains the pressure in the system. even one that will loose a pound of pressure will have adverse effects on the temps the system can maintain.

Also you say your coolant level is full, good and there is no air in the system, also good. but hows the condition of the radiator? Have you removed the guards and really looked at it? Have you had it in the mud? its possible the sides and edges that cannot be seen or easily cleaned can be clogged cutting cooling ability. Even if you have minor problems they can add up and combined cause your kind of problems.

More drastically, a head gasket leak. one that increases the pressure of the system can also cause boil overs.

Start with the actual coolant, then the cap and see what happens. Also check and clean the rad.

Good luck,
CW
 
1 - 4 of 4 Posts
Top