i just bought 85 gpz 900 the fan only kicks on when bike is hot and turnedh off i cant ride in city to long or it will over heat high way good i heard of problems with fan should i just run a toggle switch to fan anybody know anything about this problem please write back also guy i bought bike from has 20/50 weight oil runnin in it i think thats to heavy what weight should i be running in gpz 900 any one help thank you?