Fan modification to stay on until temp drops

[Valves]

Has anybody figured out how to wire the fan to stay on until the temp. drops with the ignition off? Bloody hot here today +25 degrees C and the fan took ages to switch off

[mr_diver]

Ride it.

Don't worry.

These bikes are popular in Greece and other warm countries without overheating issues. 

[greywolf]

??? It sounds like you want it to do what you are complaining it did. Do you want it to run after the ignition is off or not? From what I've read, it does that.

[Downunder]

I'm sure my fan stays on with the ignition off whenever it needs to.

[Rusty Nuts]

I was pretty sure it did, too.

[Rich:-)]

I suppose the OP could have missed a vital word - I do that all the time.

Maybe it was "Has anybody figured out how to wire the fan not to stay on until the temp. drops with the ignition off?"

[Rusty Nuts]

I thought he meant he was leaving the ignition on so as to keep the fan running, and was looking for a way he could avoid having to do it like that.

[Rich:-)]

How does it work at the moment?

I know other cars & bikes have the fan stay on independently of the ignition switch but the engine cooling effect this achieves must be very low as the coolant flow will be minimal - just convection but through restrictive pipes.
A better system is like what is employed on VW T4, it has a battery powered axillary water pump to circulate the coolant after the engine is off.

[Hugo Magnus]

What is the point of continuing to cool the bike after you have stopped?

[wurzel]

The motor continues to transmit heat to the coolant after switching off, this will pressure the coolant, so the fan continues to run to reduce the coolant temp, also moving air over the motor itself, to be most effective their could be an electric aux pump to circulate the coolant while the fan runs, but it is obviously not necessary.

[Valves]

I'm sure my fan stays on with the ignition off whenever it needs to.

Nope it does not, so the risk is by turning off the ignition the fan stops but the coolant keeps getting heated by the engine, increasing the pressure  would like to be able to leave the bike to cool down on it's own without having to wait to turn off the ignition.

[greywolf]

If fan goes off, it has cooled enough. The radiator cap is a pressure release vent. If the coolant pressure increases past about 15psi IIRC, coolant pushes past the seal into the coolant expansion tank. As the fluid cools and its volume reduces, coolant is sucked back into the radiator from the expansion tank. You really have nothing to be concerned about.