Overheating Help

H

holeshot202

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Sep 27, 2007
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Age
38
Location
MICH
Overheating Help
12/21/08

Got a 99 vmax 700 thats overheating consistently.....i'm not sure if theres just that much air in the system that needs to be bled, the water pump is burnin out, or somethiing else....i can only drive a few miles at a time at low rpm's before the engine temp light comes on. the system is pumping coolant because the heat exchangers are burning hot, but we tried to bleed the sysytem through the bolt on the top of the head, but nothing came out and tried adding coolant. It seems like the coolant line near the radiator cap seems to not be holding its vacuum...it doesnt seem to be pulling coolant from the tank but like i said, the coolant has to be flowing bc the heat exchangers are hot, but the engine is hot as well so i'm totally stumped....please help


1/2/09
tried everything you guys said...have bled the system repeatedly with no luck....put a pressure test on the coolant system to check for leaks with no luck either. is there something else that could be causing this problem? the last time we bled the system the right side (opposite clutch) heat exchanger was the only one hot...the rear and left side were relatively cold....with no leak in the system we thought it might be burning coolant having like a cracked gasket or head....seems to not be burning coolant... have no idea what the next step would be ....?
 
Make sure all your heat exchangers are heating up. If not continue to bleed your system. Also have you checked to see if your temp sensor isn't bad?

Opps! Sorry about the double post. It was an afterthought.
 
Last edited:
i'm leaning towards that in your other thread with the "is it circulating when
it over heats" comment
 
it was circulating to both side exchangers in the UP. got it home and the left sie wasnt getting warm. trying to bleed the system right now. whats the corect bleeding proceure for this sled?
 
Step 1,

1.remove seat,and bumper cover
2.lift up tail of sled slightly higher than motor
3.remove bleed bolt on rear heat exchanger
4.while slowly adding coolant in the hose,allow the coolant
to drain untill all air bubbles disappear, re-tighten bleed bolt
set sled back down.

Step 2,

1. loosen/remove the bleed bolt on the thermo housing
2. add coolant and alow coolant to flow out untill all air bubbles
disappear.
3.tighten bleed bolt, make sure system is full and cap is on.

Step 3,

Start the engine and run @ 2500 to 3000 rpm's till warmed up and
coolant circulates good, check heat exchangers should be warm
to the touch.

if air is still expected repeat above steps..
 
Update

well been bleeding the system for a2 weeks now....finally hit the sweet spot and the sled drank almost a gallon of coolant before streaming out the rear bleed screw......thought we had her fixed beat on her in the orchards for 25 minutes with no problems. hit baldwin the next morning and only made it 6 miles out from the truck before it overheated again.....i didnt think there was a thermostat in these sleds? is that the correct assumption? otherwise i belive we have the air bubble problem solved or checked off of potential reasons.....WHATS NEXT? bad head gasket? Water pump?
 
Check the head for warpage, This single piece head will warp very easily. Check to make sure the entire head if flat with a machine straight edge. If the head is warped an engine can easily get compression air into the coolant system, which will cause the water pump to cavitate and not pump. This will make the engine to continue to overheat and will continue to overheat. You can buy a new head or just have your existing head milled. I have had many triples milled .020 This is common on many Polaris models also.
 
there was an issue with the brass waterpump drive gear on the crankshaft, when the motor is cool the water pump will work until the motor warms up, then the brass gear slips on the crank,my sxr had this same problem.
 
blueracer said:
there was an issue with the brass waterpump drive gear on the crankshaft, when the motor is cool the water pump will work until the motor warms up, then the brass gear slips on the crank,my sxr had this same problem.
Click to expand...
Right,there was a member here last year or the year before that had that
problem,that's why when it's over heating check to see if it's circulating.
 
Found the Problem

did a compression test...all 3 at 135....tore the head off and found mag side blown on the bottom of the gasket. Now i have Bender tripple pipes installed by previous owner, found individual head gaskets instead of the one piece gasket normally covering all threee jugs. where do i go from here? I wanna maitain 135 psi , can i take the center gasket out of a new one and achieve tha same results?
 
I know mine has individual gaskets for each cylinder as well. I think its factory that way. Do the gaskets that are on there have the center layers removed on all 3? If so then yes remove the center layer from the new ones. I would personally change all 3 well your in there, and be done with it.
 
the 700 SX has 3 individual head gaskets, each head gasket has 3 layers, Some people remove the rivit which attaches the gaskets together and only use the top and bottom layers. I personally prefer to use the complete set and mill the head, I feel you get a better seal for compression and coolant seal. just my .02
 
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