3lakesJIM
New member
Hello out there This is my first post with Totally Yamaha! Thanks for taking the time to respond. I have a 600 v-max that was just rebuilt and runs great the only problem is that it is overheating after 10 miles of riding. At first the heat exchangers are warm and the fluid seam to be circulating then after 20 minutes or so I get a substantial burst of steam that blows out of the fill reservor and the sled begins to overheat. At this point the heat exchangers are cool. You guys have any ideas, bleeding the system has not helped at all. Any ideas Thanks 3lakesjim
Is the thermostat opening as closing properly?
Check for an air lock and also check for a leaking head gasket. Red Head's don't have thermostats. If the head is warped, simply mill and use OEM head gaskets. Al
3lakesJIM
New member
O2viper700 said:
Wea re currently running this without a thermastat. Could that be the problem?
3lakesJIM
New member
I will check, that would expain the build up of pressure in teh system. Thanksalswagg said:
01sxr700
VIP Member
Sounds to me like a head gasket leak. Try re-torquing the cyl head. If there was a air lock then the running boards would not warm up.
01sxr700
VIP Member
Why did you overhaul the motor? I had a cyl redone once and it came back .009" shorter than original. One layer of an old head gasket made up the difference on that cyl.
3lakesJIM
New member
It overheated last year and a freind of mine disregarded the idiot light and blew the engine. Lost all three pistons and two jugs but I did not mill the head. It sounds like it may be the issue. Last year the carborator heater valve fitting release and trained the anti-freeze from the system. The problem of overheating last year could be the reason it is overheating now. Can't figure this one out. I had the sled looked at by a very good snowmobile mechanic in Eagle River WS and he can't put his fingetr on it either.
Nice laker in your photo!
Nice laker in your photo!
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take the seat off, raise the rear end higher than the filler neck on the coolant resivoure and then start the sled and use the bleeders at the back of the tunnel to get all the air out of your system. If you didn't use these bleeders the first time around you didn't get all the air out of the system. They are under the seat so you wouldn't have seen them without being told they are there.
01sxr700
VIP Member
If the above doesn't work you might want to consider taking the cyl head off and putting a straight edge across all the cyl's and check the head.
If everything else checks out, you may want to ensure the water pump impellar is not damaged or stripped or loose.
To do this you will have to remove the exhaust and then remove the water pump cover on the lower part of engine...it has a resueable O ring gasket.
If the impellar is in place and not damaged there could be another problem...and you won't like this!
There is a brass gear on the crankshaft that meshes with the shaft that turns the water pump and oil pump...these brass gears sometimes get damaged and only sparatically turn the shaft or not at all...crank has to come out and appart to fix this issue...hope thats not your problem.
To do this you will have to remove the exhaust and then remove the water pump cover on the lower part of engine...it has a resueable O ring gasket.
If the impellar is in place and not damaged there could be another problem...and you won't like this!
There is a brass gear on the crankshaft that meshes with the shaft that turns the water pump and oil pump...these brass gears sometimes get damaged and only sparatically turn the shaft or not at all...crank has to come out and appart to fix this issue...hope thats not your problem.
Could be your brass gear on the crankshaft that runs the water pump and oil pump. The gear is pressed on the crank and if the tolerances weren't quite right between the two parts during assembly (crank OD on small side and/or gear ID on large size), the press fit wasn't as strong but would work fine when the engine is cold/cooler. When engine heats up the brass gear expands enough to spin on the crank under the load of turning the pumps.
This is semi-common with the Yamaha trippples, and doesn't always show up when the sled is newer. It would explain the heat exchangers getting nice and hot initially, then cooling off (as the pump stops working). Of course if you have gasket or bleeding issues as well, you need to get those resolved, but a good way to test the gear theory is to make sure you get the cooling system filled and bled, and no gasket issues, then run the sled keeping an eye on the temp of the running board exhangers. See if the exhangers cool down before the coolant blows out the overflow and starts to empty the system (in your desc above, the coolant bottle emptied before finding cool exchangers, and you may have had air in the system as well).
To fix would require a crank rebuild, letting the rebuilder know to make sure to fix the issue.
This is semi-common with the Yamaha trippples, and doesn't always show up when the sled is newer. It would explain the heat exchangers getting nice and hot initially, then cooling off (as the pump stops working). Of course if you have gasket or bleeding issues as well, you need to get those resolved, but a good way to test the gear theory is to make sure you get the cooling system filled and bled, and no gasket issues, then run the sled keeping an eye on the temp of the running board exhangers. See if the exhangers cool down before the coolant blows out the overflow and starts to empty the system (in your desc above, the coolant bottle emptied before finding cool exchangers, and you may have had air in the system as well).
To fix would require a crank rebuild, letting the rebuilder know to make sure to fix the issue.
sideshow beat me to it while I was typing. 
3lakesJIM
New member
3lakesJIM said:
Perplexing overheating issue. I have replaced the head and gasket to try elminate another reason why this sled continues to overheat after 8-10 miles of riding. Has anyone heard of the the gear that drives both the water pump and the oil pump slipping on the crankshaft after the sleds warms up? Running out of ideas!! Thanks.
warx22
New member
dont think its ur head gasket cause ur cyls would take on coolant and run like shit or not at all check for air in system and if that dont help check water pump which is a big job if its the pump cause it runs off the cranks and most people dont have the tools or the knowledge to rebuild the crank hope this helps
Devilin AblueDress!
New member
I dont think your sled should have a thermostat. Sometimes bleeding them can be a real PITA! Exhaust that theory before you tear into engine.
bluemonster1
LIFE MEMBER ONLY ONCE!!!
yes they can be hard to bleed on the redheads.I think I once removed the coolant cap,topped it off and put my mouth over it and blew into it(with rear bleeder open) blew a little and added more coolant..kept repeating this procedure until I started to hear and see coolant coming out steady with out air bubbles.Then kept up a little longer at it making sure I had a steady stream of coolant coming out.Topped up the bottle and ran it until hot and all is circulating..this was 3 years back.