Overheating Help

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holeshot202

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Joined
Sep 27, 2007
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30
Age
38
Location
MICH
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 ....?
 
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i have the same sled. on mine you have to take the bleeders out to get coolant to come out. just cracking them loose wont get anything to come out. take a hose off and stick it in a bucket. fire it up and you should get coolant in the bucket. if not the pump is bad. if you get a lot of coolant in the bucket fill the systems up and bleed it. make sure you raise the rear and fill it really slow. this will help to keep the air out. fire it back up. if it still gets that hot you probably have a blown head gasket.
 
have you ever bleed the sytem right??

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 on top of the thermostate 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..
 
you got a rad hose pinched someplace?? this is strange....when it's over heating is it circulating coolant??
 
well the first few times we bled the system the coolant was circulating....all the heat exchangers were very warm....the last time only that one heat exchanger got hot, so it didnt seem like coolant was circulating.....but we tried everything imaginable to get this thing to bleed coolant but after hours of trying we gave up hoping that a pressur etest would reveal a leak, but it did not...so we have no where to go now....?

evryine ive talked to say that bleeding the coolant shouldn't take that long...and if it didnt spit coolant after that long there has to be a larger problem somewhere
 
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it's not a bleeding issue you have problems elsewere

do the checks i said above,we need to eliminate area's..
 
we jack the back end up and when we crack the coolant cap all the coolant comes flowin out the front. where is the thermostat? it will build pressure . we have the traenough to squirt out the bleed hole.the track is about 2 to 2.5 ft off the ground and when we pull the cap off all the coolant comes flowing out. do you put it in the back hole? that doesnt make sense but I need some help here. I have heard numerous stories on the bleeding procedure and not sure how exactly to do this...
 
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The termostat is located at the end of the hose that comes out of the coolant bottle,
were the rad cap is.Just like a car they are made to let a little coolant thru when cold [to not block the pump]and will still let you bleed the air out.But when you start to ride the sled it will over heat in a short time.
 
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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?
 
I am wondering if you either have a thermostat that is operating intermitently or a water pump that is intermitent. I believe the water pump on some SRX's had problems with the impeller not having a tight fit on the shaft so it would not always push coolant.

I have also had the experience of troubleshooting a sled that would overheat very quickly only to find it was repaired and when it was reassembled, the coolant hoses were connected wrong.

Has any part of the cooling system been diassembled?

When the sled has run for a few minutes and the thermostat opens, you should see coolant flowing through the coolant bottle, that is, there should be some movement of the coolant in the plastic tank. Without running it on snow, that is running it in the garage, the heat exchangers should start getting warm at the coolant input to them and progressively get warmer along the whole collant path as they heat up.

This is difficult to troubleshoot from a distance! Let me think about it some more and I will suggest things to try.
 
Your sled should not have a thermostat. If it does its under the gooseneck on the head. Hows your compression on all 3. Do compression test and post the numbers. If you have a blown headgasket you should have a lower compression on that cylinder. Where r u i MI?
 
located just north of grandrapids in the comstock park sparta area.....but gonna try a compression test tomorrow and ill get the numbers out to ya......my long time yamaha buddies still have never seen anything this confusing....
 
I am in Ada. I was gonna say when I get a free minute or 2 I could probably come take a look.
 
Holeshot, have you checked your head for warpage? If the head is warped, compressed air from the combustion chamber will enter the cooling system. This air will cavitate the water pump and cause a no circulation problem. It will also cause the cooling system to "boil" over into the coolant recovery bottle. If the head is warped, you can either replace or have it milled at a machine shop. If you choose to have the head milled, definatly use the complete head gasket, do not remove any layers. good luck Al
 
It had a bad head gasket. Thanks everyone for your help. The head gaskets had a layer removed by the previous owner and one of them had no gasket material left around the cooling jacket. a new set of head gaskets and he was down the trail last weekend. after bleeding it 3 or 4 times we figured that air was getting forced into the system somehow and pulled the head off. bingo thanks again guys
 
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