[jmx663]

I just finished rebuilding the top end on my 03 mountain cat 900. I jacked up the front end and filled it with coolant from both the overflow bottle and the hose off of the cylinder head. Pretty sure I got all the bubbles out. But as soon as I start it, 2 seconds later it starts shooting antifreeze out the overflow. What am I missing?bang your headbang your headbang your head

 

[auburn6887]

the rear of the sled needs to be higher not the front
just kidding
rmove the hose from the bottom of the coolant bottle
remove the hose from the thermostat housing
slowly fill the hose from the bottom of the coolant bottle
then fill hose at thermo stat
put hoses back on
fill coolant bottle less than 1/2 way
run sled with cap off
add coolant as needed as sled warms up
if it is pushing coolant out again
you have to get a pressur tester
auto zone rents it
pull spark plugs
fill coolant and pressurize system looking for leak
it could be bad base gasket or orings
good luck

 

[jmx663]

Thanks, ill let you know where I come out

 

[109jb]

If it is blowing the coolant out of the bottle you may have a bad or pinched o-ring on the head.

 

[jmx663]

Thats what im thinking. I havent had time to tear it all apart but I pulled the plugs and can see little drops of antifreeze on top of the piston.

 

[jmx663]

I finally got the time to tear it apart and it was a pinched o-ring between the cylinder and the head

 

[auburn6887]

easy fix

glad you found it was an easy fix