Coolant Problem on 2001 Kawasaki 1500 Nomad?

[Donk~A~Donk]

My Nomad spits out coolant into to the resevoir while its running or reved up and then tends to shoot it out the overflow on the reservoir but when it cools down it sucks it back into the engine. Sometimes it fills the resevoir almost full, while running.... does anyone know what can cause this and what I need to do to fix it. Thanks

 

[bikinkawboy]

It's normal for the reservoir level to go up when the engine is good and hot compared to dead cold. That's why the overflow tanks usually have a full/cold and a full/hot level. If the coolant is foamy and bubbly, that's usually the sign of a leaking head gasket.

 

[guardrailjim]

Worn radiator cap - pressure relief spring or gasket
Damaged radiator filler neck - preventing the radiator cap from making a good seal.