When should the fan cut in? At what temp reading should it kick in?

Fan switch should starts to close when temp reaches 98-102 deg C and then starts to open once temp drops to 93-97 deg C.

Mine went just before the red and hadnt cut in so I turned it off, looks like I my need a new sender

vfrderek wrote:Mine went just before the red and hadnt cut in so I turned it off, looks like I my need a new sender

best way to test whats at fault is pull the lead off the switch on the LHS/NS of the bike and short it to the frame if the fan comes on its the switch if they fan dont then the fan is up the duff,

dont make my mistake of powder coating all the bits putting them together then finding out that i had a VERY poor earth path.

Nice one, will give that a go Cheers Rick!

Ok earthed the temp sender wire and fan cut straight in.
Let bike run until it reaches the red and didnt cut in, does it need to run on a bit more? I didnt wanna over egg it

Sounds like your temp switch is fugged, but before you go to the expense of replacing it, check that the wiring in that part of the loom isn't faulty.