Heating problem!

Fermen · Post by **Fermen** » Sat Feb 06, 2010 3:42 pm

Hello everybody i have some trouble with my 86 Vmax.When im out riding the cooling can be allright but suddenly it overheats!.Been checking in the radiator frekvently and the cirkulation seems to work.Every thing else is allright jetting,clutch and i been riding in conditions thats not icey.Has anybody hade trobble like this?air in the system?

jefflanthier · Post by **jefflanthier** » Sat Feb 06, 2010 3:58 pm

probably a faulty thermostat! just remove it and make sure you warm up the engine before you drive it hard 3 to 5 mnutes, and check the antifreeze with a tester to make sure the mixture is right. Its the water that cools the engine not the antifreeze. Too much antifreeze and not enough water will make it run hot its a proven fact.

Fermen · Post by **Fermen** » Sat Feb 06, 2010 5:11 pm

jefflanthier wrote:probably a faulty thermostat! just remove it and make sure you warm up the engine before you drive it hard 3 to 5 mnutes, and check the antifreeze with a tester to make sure the mixture is right. Its the water that cools the engine not the antifreeze. Too much antifreeze and not enough water will make it run hot its a proven fact.

Sorry jefflanthier i have allready removed thermostat accouple years ago and the antifreeze is right 50/50

chrisrider63 · Post by **chrisrider63** » Sat Feb 06, 2010 7:32 pm

Water isnt getting through maybe, do you have a vacum line from your crank to the fuel pump off and/or broken, cracked?? Take the pipes off and get a miror and look to see if the pistons are scored or marked. Mine stuck a piston because i didnt have a vacum line hooked up and Tyler pointed me in the direction of the vacum line but it was too late by then, but i just sanded the pistons down and was on my way.

Post by **Vmax540** » Sat Feb 06, 2010 11:04 pm

Feel your rear heat exchanger if, it is not hot then it is not circulating and yes, there are air bleed bolts under the seat on the exchanger. Pick the rear up and crack the bolts while it is running.

Fermen · Post by **Fermen** » Sun Feb 07, 2010 5:08 am

Hello Vmax 540 the rear heat exchanger gets hot but it will try your idea with the air bleed bolts rear.The mystiry is that i can go out riding for 30-40 minites and everything works fine but suddenly its overheating..it feals like the circulation suddenly stops but if it then cools off the cirkulation works again!!thank you everybody for your help. Please give more idies...

Post by **Vmax540** » Sun Feb 07, 2010 8:14 pm

Did you remove the thermostat or remove the valve plunger and spring ? I have been told it is possible for water to circulate to fast and overheat which, is why a some use a washer with the same size hole as a gutted thermostat. On the opposite end as some have mentioned you may have a partially blocked radiator ? Maybe time for a coolant flush with new coolant and to drain the system take the hose off and run it into a bucket this will show if you have a good water pump ?

Fermen · Post by **Fermen** » Mon Feb 08, 2010 4:41 am

Hello it`Â´s the complete termostat thatÂ´s removed.Removed the seet yesterday and tried to bleed rear but now it seemÂ´s like the circulation stopt completle.Will try too wash the cooling system like you sad Vmax 540 or else it must be the waterpump..

remove engine

.to be continied..

opsled · Post by **opsled** » Mon Feb 08, 2010 8:30 am

You may have a water pump impeller that is spinning on it's shaft. The impeller is aluminum and the shaft is steel. They expand at different rates when heated and it's possible that the impeller becomes loose at operating temperature. The impeller is held tight to the shaft by a locknut and I don't think it's keyed so this may be the problem if the retaining nut has come loose.. Checking is not easy. It requires removal of the engine and gearcase housing in order to remove the impeller cover to inspect the impeller and shaft.

Hope you find something else but if not you may need to look at this to be sure.

Good Luck, Phil (opsled)

Post by **Vmax540** » Mon Feb 08, 2010 10:41 am

Check Part#'s !

Shaft
http://cgi.ebay.com/ebaymotors/YAMAHA-S ... 45f0e0c1b3

Impeller
http://cgi.ebay.com/ebaymotors/NOS-YAMA ... 2eaa6605e0

Gasket
http://cgi.ebay.com/ebaymotors/NOS-YAMA ... 2c5270e97f

Fermen · Post by **Fermen** » Thu Feb 11, 2010 2:42 pm

Hello yesterday was removal of engine night.Tryid cleaning the cooling system! It did not work,.removed the engine and it was the waterpump impeller.It was loose from the axel.Will be fixing that and change some bearings+seals.Thanks for your help everybody!

Post by **tyler440** » Thu Feb 11, 2010 4:25 pm

thats good you found the problem... i dont think i have ever heard of that happening... but ill have to keep it in mund if we come across it again... thanks for the update