hi i own a cbr600f4 my problem is that the radiator fan does not kick when it supposed to....at first i cheak the fuse and the fan itself... which both are fine...then i notice that when i lean the bike on the left side for a while (the side where fan thermoswitch is atttached to radiator fan) the fan kicks in for a while and then stops....same when on side stand....but as soon as it gets upright it stops after couple of seconds......what could it be???if its a bad thermoswitch then the fan shouldt kick in any way......could it bee cloged radiator?????i would like to hear your opinios... thanks in advance

 

Look for a bare spot in the harness that touches ground when leaning left, or a loose ground connection between the fan-radiator-frame.

 

Although I like the suggestion above, for my peace of mind, check the coolant level please.

 

sorry for the delay.... no bare spot in the harness or loose ground connection....also coolant level is ok.....when i said that the fan kicks in when i lean the bike and stops when upright it is not like on and off....its like it kicks on and stay for 3-5 seconds on when its upright....so i think its not something with the harness......

 

Just make left turns.....j/k

Set the bike upright, run the engine and then remove the radiator cap. If the coolant is swirling then the pump is circulating. I'm hard pressed to say but it must be something that is changing when you lean left or are upright. Move the bike around and see if the circulation pattern changes between the two. If so, then look at the pump and thermostat as culprits. Failing that, I'm wondering if there's a solder joint in the ECU.

 

yesterday was a shiny day so i decide to spend some time fixing my bike....finaly were the cables from the ignition switch underneath the lock that were cousing the broblem....the guy who install the allarm 15 years ago had places two tie wraps very tie so the insulator of the cables worn.....thanks you all for your help