coolant loss out the overflow Help!

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Aug 14, 2007
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#1
hi i have a 2005 Honda cr85 and i am loosing over half of the coolant out the overflow tube. When i start it up and rev it i have lost nearly half the coolant in about 10 seconds! Any ideas?? Help!
 
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#4
I know exactly what is it. The same thing happened to my old 2000 rm125. We bought it off a guy on fleabay. We tried the radiator cap and it didn't work. Then we went to the head for answers and it turned out the guy left out an o-ring (not ring) underneath the head. This is probaly whats wrong with your bike.
 
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#5
Race_Bennett said:
wow thats wierd... maybe water pump?
yup, I would replace the radiator cap, and then check the water pump. and always the obvious, clogged radiator, hoses, that stuff.
 

ghunter

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#6
If you are blowing that much coolant out of the radiator, you probably have a blown head gasket. If you haven't recently serviced the top-end (meaning you may have installed the gasket incorrectly) it is probably time since you will be in there anyway.

Check your silencer packing and see if it is wet. You can remove just the silencer and feel if it seems like it weighs 10 pounds. If so, its probably full of coolant that is pushed out of the exhaust from the damaged head gasket.
 

oldguy

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#7
ghunter said:
If you are blowing that much coolant out of the radiator, you probably have a blown head gasket.
Ghunter hit it right on the head :)
Good way to prove it is take the radiator cap off with the coolant full and then start the bike. Very quickly you will see bubbles in the coolant from the exhaust blowing past the gasket.
You may have it as simple as a new gasket or as bad as a warped head.
 
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#8
i also had to replace that right when i bought it. i thought i had ruined it on my first crash... i was so sad :( but then we found the problem and fixed it right away!
 
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#9
MOTO ON RM250 said:
I know exactly what is it. The same thing happened to my old 2000 rm125. We bought it off a guy on fleabay. We tried the radiator cap and it didn't work. Then we went to the head for answers and it turned out the guy left out an o-ring (not ring) underneath the head. This is probaly whats wrong with your bike.
Except CR85s do NOT use o-rings for head gaskets. The gasket probably is blown, though, but also check the shape of the radiator neck. I know you tried a new cap, but if a radiator has been tweaked the hole can be tweaked also. Without a good flat sealing surface for the cap you can have coolant pushed through into the tube. I'ts at least worth a look.