# How do u know?



## countryboy61283 (Mar 20, 2010)

How can you tell if you blew a head gasket or if the thermostat is sticking on a brute force?


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## 2010Bruterider (Jun 20, 2010)

If you blew a head gasket, either water will come out the side of the engine, or out the muffler, or your radiator fluid will smell like exhaust and you'll see bubbles in the rad. And as far as the stuck thermostat, it you don't see any flow in the Rad, it's stuck shut. You could remove it and put it on the stove in a pot of water and test it.

To the Batcave!


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## brute for mud (Jul 15, 2010)

it could also milk the oil


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## J2! (May 8, 2010)

A sure sign of a blown head gasket is it pushes water out into the overflow bottle. And either water in the oil or oil in the water. Also look for a sweet smell coming out of the exhaust, if so, it's blowing coolant out of the exhaust which means a head gasket is gone as well..


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## countryboy61283 (Mar 20, 2010)

The reason why I ask is because I can only ride for about 25 min then it will over heat. I have a Manuel fan switch and leave it on. The rad is full also and I cleaned it real good. I notice when it's idling I can take rad cap off and it's bubbling out of the opening. I can see it flowing I think. It looks like its pouring out of the fins inside. The oil hasn't been milky and I haven't seen white smoke or sweet smell out of the exhaust.


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## jakedogg (Aug 14, 2009)

You have air in the system or your radiator is not clean.


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## countryboy61283 (Mar 20, 2010)

I know the rad is clean, I took it off and cleaned it until I could see all the way threw it. Would air in the system cause it to over heat like that? I filled it up and let it run until I thought all the air was out


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## gav09 (Feb 1, 2012)

idle it with the cap off untill both hoses are hot. rev it up every once in a while. if you had a airlock it could overheat. if both hoses are hot the stat opened


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## countryboy61283 (Mar 20, 2010)

Hoses get so hot you can't touch Them


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## gav09 (Feb 1, 2012)

doesn't sound good then. especially if its bubbling in the radiator


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## countryboy61283 (Mar 20, 2010)

What you think? Head gasket?


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## gav09 (Feb 1, 2012)

yea. another way to be sure is you can put each cylinder on tdc and supply air to the cylinder. if the level in the radiator rises or if coolant bubbles then head gasket for sure


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## countryboy61283 (Mar 20, 2010)

Just stick a air hose in spark plug hole?


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## gav09 (Feb 1, 2012)

i use a leak down tester but you can take out the schrader valve in a compression tester and hook it up to air. rubber tipped air gun would work but not as effective. basically your pressuring the cyl and seeing if compression is going into the cooling system


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## DaveMK1 (Nov 8, 2009)

What does your coolant smell like in the radiator? and is your overflow bottle full?


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## countryboy61283 (Mar 20, 2010)

I think it smells ok, haven't checked overflow bottle


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## Waddaman (Oct 3, 2010)

Coolant to me always smells like a really really condensed celery? lol had to put that in there. Anyway.

Run the engine with the cap off and let the thermostat open up, then dump coolant in as it needs it. Id say it's more likly you have a bad air pocket than a head gasket especially if you just removed the rad.

If there's air in the system it can prematurely make the thermostat open as well. Before Id do any of that id check for air first.


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## DaveMK1 (Nov 8, 2009)

Waddaman said:


> Coolant to me always smells like a really really condensed celery? lol had to put that in there. Anyway.
> 
> Run the engine with the cap off and let the thermostat open up, then dump coolant in as it needs it. Id say it's more likly you have a bad air pocket than a head gasket especially if you just removed the rad.
> 
> If there's air in the system it can prematurely make the thermostat open as well. Before Id do any of that id check for air first.


Definitely check for an air pocket first like as stated above. If your antifreeze smells like combustion gases then it could be a sign of your head gaskets starting to fail. Bike might run fine cause they haven't completely blown out yet but they are on their way. 

Look at your overflow bottle for a higher than normal level while the engine is running and up to temperature. Your coolant level will show high cause the combustion gas is pushing through the system and relieving the pressure on the radiator cap allowing it to escape to the coolant overflow bottle.

I'm really not too familiar with the relation of the water jackets to the cylinder on these bikes, but on previous engines I've worked on, those were some of the tell tale signs of head gaskets going out.

Good luck man and keep us updated.


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## countryboy61283 (Mar 20, 2010)

I have clear tubes running to my bottle and I notice coolant was in it


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## DaveMK1 (Nov 8, 2009)

countryboy61283 said:


> I have clear tubes running to my bottle and I notice coolant was in it


Is it present while the engine is running and warmed up?


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## mmelton005 (Oct 12, 2011)

If you have an O'reilly auto parts local go there and tell them to get your or order Lisle part number 75500. It's great. I'm not sure if we are allowed to post outside links or not just google lisle 75500. It's a GREAT tool


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## countryboy61283 (Mar 20, 2010)

I pulled the thermostat and check it on the stove, it's closing and opening like it should


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## countryboy61283 (Mar 20, 2010)

I put my stat back in filled everything back up, let it run for about 15 min, then increased Rpm slightly for about 3 min let off and coolant came shooting out


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## CRAZYCRACKAZ71 (Oct 8, 2011)

Shooting out from where? If the tail pipes ur head gaskets are gone. I have a kfx700 race bike at the house now with the 700 vtwin in it and when started water comes out motor and flys out tail pipe. These head gaskets are gone and i will b fixing them.


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## countryboy61283 (Mar 20, 2010)

Out of the rad cap, I took it off to get the air out of the system


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## countryboy61283 (Mar 20, 2010)

Well I took my front headline off tabs notice some white residue inside the head pipe. What would be that from


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## 2010Bruterider (Jun 20, 2010)

It's probably from the aluminum reacting to the antifreeze. I think that's normal. 
And you don't have to Rev the engine to get the air out. It might help heat it up faster, but otherwise unnecessary. Just let it idle until you see water flowing through the Rad. How for ipu have your hoses ran? My belt side hose goes to the top of the Rad, and the left side goes to the bottom of the Rad. If you swap them up, it could be sucking air instead of coolant. 

To the Batcave!


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## walker (Apr 5, 2009)

i would keep running it without the cap on .. you def have air in your coolant system. if it was a head gasket you would have milky oil and water running out the tail pipe.


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