SNOWRULES
New member
was on the trail last weekend and my overheat light started blinking. thought maybe it was an air bubble so i bled the system with some water i got from a nearby house. took it out light came on again. thought maybe it was the thermostat so i pulled the housing off sure enough it was busted. figured i'd just take it out and run it without it, so i cut the end housing off and put it back in for some restriction. was able to limp it home but still kept overheating the whole time. also noticed i wasn't getting good flow through the boards exhaust side board was cold rest of the exchangers were warm. got a new thermostat put it in bled the system really well ran it in the basement good flow through all the coolers all got nice and warm. took it out was fine on the lake for 30 mins no light lake had 3-4 inches of powder. got up on the hard packed trail after 15 minutes light came on CRAP!!!! let her cool down got back on the lake no problems. ran it for almost an hour on the lake no light. got back on the trail light came on again in 5 minutes. trail had enough snow it shouldn't be overheating. went home parked it for the night. next day got thinking maybe the rad cap was no good. took the rad cap off my sxr put it on and took it out on the lake no problems. took it out on the trail 15- 20 mins no problems good flow through the exchangers all nice and warm. put close to 150kms 2-3 hours riding on the trails in the same conditions it overheated in before no breaks no stops with no problems at all. question is could it be that simple that my rad cap was toast? would this cause the overheating even after the new thermostat? i'm thinking if the spring got week and was letting the cap open too soon i wouldn't have enough pressure to get good flow through the system. sorry for the long post but any input would be great guys.
daman
New member
Could be,,,happend on a car i had once,,buy a new cap and put it on.........
SNOWRULES
New member
anyone else have any input
mrviper700
VIP Lifetime Member
On the thermostat you will see a small hole in the outer ring, this hole lines up with the little slot in the thermostat housing, it allows any air in the system to be bled out and into the overflow tank. If you have the thermostat in the wrong way and a bad cap, sure it will overheat. the cap lets the system build pressure and this raisies the boiling point of the antifreeze/water, other wise it will boil and produce steam and block coolant flow at 212 degrees.
SNOWRULES
New member
hole and slot are lined up was very careful about that. i guess it could just be i had a bad cap. got a new one to try this weekend so we'll see if i can get it to overheat again. thanks
SNOWRULES
New member
update: put a new rad cap on took it out ran fine all over the lake got up on the trail same problem 3 minutes up the trail overheat light comes on. let it cool back on the lake no problems. back up on the trail overheats again. i know the sensor isn't bad because when i pull over and lift the hood i can hear the coolant boiling and if i drop a little bit of snow on the heads it almost sizzles off and does sizzle off the powervalve housings. i have a brand new water temperature sensor installed in a brass "T" about 3 inches from the reservoir bottle in the hose that comes off the bottom of the reservoir and goes to the water pump on the bottom of the motor. however when the motor overheats i have no reading on that temp sensor. but sometimes when it overheats i pull over and stop the motor and the sensor all of a sudden shoots up to like 180. when i had her on the trail last weekend and it was running ok i was getting a reading on the temp sensor of around 140 with low snow. it almost seems like i have intermittent coolant flow, because when it gets too hot i have no flow in that hose. i know that hose is under suction and has a spring insert in it to keep it from collapsing. could it be that spring has failed or shifted and as the motor gets warmer from normal lower snow conditions the hose gets soft and collapses? i've had this same hose with a water temp sensor installed for the last 3 years and have had no problems and good temp readings the whole time. i just put a brand new pump cover gasket on when i had it apart. the impeller is good and the gears do not seem to be slipping on the crank because if i try to tighten the impeller bolt the whole motor turns over and if you crank the cord the impeller spins fine. HELP GUYS I'M GOING NUCKING FUTS!!!!
SNOWRULES
New member
could a bad seal behind the pump impeller be my problem? it looked ok. is it hard to change? do i just have to remove the impeller and pop it out and new one in? i've tried everything else this is my last guess at what it might be.
bluewho
Active member
Do a test on the antifreeze see what it is good for.Pull out the thermo again and check it in a cup of hot water.It shure sounds like a air lock or faulty thermo.
daman
New member
CHeck the thermo out, it should open at 142deg.F,the opening should
be more than 8mm, and close at 116+/- deg.F..
be more than 8mm, and close at 116+/- deg.F..
SNOWRULES
New member
thanks guys i'll check the thermo out. the coolant is brand new so i figured it would be good even have a bottle of water wetter in her.
bluewho
Active member
yOU MUST ADD WATER 50\50 OR IT WILL OVERHEAT.Use a tester mix for forty below
bluemonster1
LIFE MEMBER ONLY ONCE!!!
I run mine at 60/40 mix and is fine.
daman
New member
60/40 is what the service manuals call for, that's the ratio i use and never
a over heat problem..
a over heat problem..
mrviper700
VIP Lifetime Member
If the mech. seal was it, will do 2 things, it will drip coolant out the bleed hole and into bellypan, or it will inhale coolant in a cylinder, very easy to idntify by the spark plug, will be all clean and wet looking piston wont have any carbon on it and plug can have a fuzzy/crusty green appearance if coolant intake is only slight.
Since you now have a new thermostat and its in properly, I would check for air in the system, remove seat and bleed rear heat exchanger, bleed water rail on engine, add water to system while running engine and see if it will burp any air, this causes intermittent coolant flow(air lock or pockets).
If it still heats up after doing this then I would pull the waterpump cover and inspect the waterpump impeller splines. While your down there inspect the lower hose as you mentioned for the spring to be in there and if the hose collapses easily(soft)
Since you now have a new thermostat and its in properly, I would check for air in the system, remove seat and bleed rear heat exchanger, bleed water rail on engine, add water to system while running engine and see if it will burp any air, this causes intermittent coolant flow(air lock or pockets).
If it still heats up after doing this then I would pull the waterpump cover and inspect the waterpump impeller splines. While your down there inspect the lower hose as you mentioned for the spring to be in there and if the hose collapses easily(soft)
SNOWRULES
New member
mr viper when you say inspect the impeller splines do you mean on the inside of the impeller for wear or the shaft the comes off the crank or both? when i had the pump cover off i pulled the impeller off and all seemed ok. the impeller seemed nice and tight on the spline shaft and there was no rotational play. the ceramic seal and shaft did however have a bit of black crud on them i just figured this was from and acceptable amount of oil seapage but maybe it was rubber from a worn seal. you said if the seal was bad it would inhale it or drip coolant out the bleed hole into the bellypan what bleed hole would it drip from? so far my plugs have looked fine nice and dry. warmed the sled up today just idling and all the exchangers got warm. popped the cap off the reservoir and saw lots of movement when i reved it up a bit. after idling for almost 15 minutes the water temp sensor hit about 140 farenheit. so the impeller and all that from what i can see is working.
SNOWRULES
New member
bled the coolant system really well again this afternoon while it was running coolant shot 5-6 feet out the rear bleed screw no bubbles. took it out still overheated. decided to check the thermostat stat was busted again failed in the same way as the last one failed. pin in the housing end snapped sideways breaking the brass colar around it so pin was bent at like a 45 against the housing. so now thats 2 thermostats in 2 weekends that have failed. is there something that causes the stats to fail or am i just having brutal luck. the second stat was a used one out of a sled that was running fine. i have another new one on order but won't be here till this coming friday so can't do anymore testing till then. am i missing something here guys? has anyone ever seen this kinda thing happen? this is getting ridiculous.
bluewho
Active member
I had the same thing happen twice the long thermostat are no good i dont know why but if you get the shorter style that yamy sells you will have no more problems.
SNOWRULES
New member
what machine is it off? the shorter style