kx85 radiator coolant?

[kx105_rider]

i have a 2003 kx83 and want to know why is spiting all the Antifreeze out the overflow tube the more i rev it the more it spit it out. i called a shop and they told it could be a bad radiator cap?

 

[Patman]

Sounds like a reasonable place to start based on the limited amount of information.

 

[Solid State]

If the cap is OK, then the coolant system could be being pressurized by engine combustion. Could be a seal or gasket if the cap checks out.

Good luck.

 

[Jasle]

if spitting out with the revs then its most likely a blown head o-ring. the caps usually only leak after getting hot and pressurizing the system.

 

[Zach10122791]

for sure it's the head gasket all bikes do it overtime

 

[yz80nbeast]

im gonna lean towrd your cap because i changed every seal and gasket in my engine and my bike started doing that today and i just put my new top end gaskets on today(brand new from kawasaki the ones that came with the gasket kit was crap) and my bike was doing this so im going with the cap im gonna change mines mayb tommorow and ill let you know

 

[oldguy]

Very unlikely it has anything to do with your cap. If it is bubbling and pours out while revving you are bleeding compression into the coolant from the cylinder. You have either
1) a blown gasket or O-ring at the head
2) a warped head that does not meet the cylinder evenly
3) Improperly torqued head bolts (or nuts)
4) head studs that are either stretched or stripped.

Easiest way to confirm that it is not the cap- start the bike with the cap off. Watch the coolant as you rev the bike. If there are bubbles in the coolant they are from exhaust gases being forced into the coolant by one of the above problems.

 

[husabutt]

Also check that the radiator overflow hose nipple is not pushed in which will cause the cap to release pressure prematurely. This can be caused by installing a new overflow hose. Counter hold the nipple when installing a new hose as shown in the pic below.

 

[00KX250Byrd]

Was it your radiator cap? My sons YZ80(105 kit) just started doing the same thing. Fluid would drip out of drain hose after it was warm. I warmed it up with the cap off, and noticed movement of the fluid in the radiator. If it is a head gasket, should I be looking for bubbles?

Britton