My speed four runs ok. Fan comes in/out no problem. Then when I stop, the heat goes up fan cuts in and steam / water come out from under my seat. The only way I stop this happening is to allow the expansion tank level to empty and then I don't have this problem.. Anyone good with coolant system problems with any idea how to solve this one .
It's either a faulty thermostat or a blown head gasket. You can get a sniffer test to check for combustion gasses in the coolant. Maybe check the thermostat in a sauspan on the stove first.
There's definitely a fault in there. Is coolant old ? Water pump maybe buggered , or as @Linx says head gasket or hopefully only the thermostat.
Update. Flushed and topped with new but temp went up even when can came on still kept climbing till temp alarm.. took rad cap off and turned it around then the temp came down when the fan came in .I have ridden after and seems ok
