Motorcycle Repair: Gurgling sound in the Cylinder Head, head gasket, ls650

Question
Help! I have a 97 LS650 Suzuki Savage. I took it in to the local dealership to have the head gasket and seals replaced. The head does not leak anymore but after I ride it for awhile (30 - 45 minutes + ) and I kill the motor, I get "gurgling" and sucking sounds coming from the head. It sounds like a bathtub draining. This will continue for 2 to 3 minutes. Any suggestions?  

Answer
Max, after doing some research and having knowledge on that motor i cannot come up with anything that would cause this issue other than the breather for the crankcase is plugged off. i would check to make sure that the breather is open. should be located to rear of crank cases. i will keep thinking on this but it most likely is the breather causing pressure buildup in crankcase. let me know

Eric