I am working on a 87 lz 1000 for a buddy, it would not heet up, i put in a new thermostat and flushed the coolant. when it is up to temp after a ride, if you turn off the key the fan stays running for 2 min. this is normal. but you can hear the coolant boiling. is this something to be worried about? I made sure that there was no air in the system by opening the bleeder on the thermostat housing. soo with that said should this be something to be looked into?
thanks Ron

 

hmm, first thought is to check the water pump impeller. ie, lack of circulation Good luck and let us know. Thanks

 

that was the first thing that i checked, it is in good shape and circulates great. the coolant that I drained out was clean. no grit, or rust. the old thermostat was stuck wide open. i replaced with a kaw original. the fan cycles like it should. it seams to only be boiling in the res tank.