Just wondering if all thermostats for a 125cc trials bike activate the fan at similar temperatures. I have a Sherco 125 2015 and wondered if a thermostat from another bike would be suitable, or are all thermostats specific to the bike they are fitted.

Normally specific.some fit in the rad, some inline with the water hoses,but as you know yours is in top of the rad.

Thanks bilks. Are they generally set to switch on the fan circuit at a simulator temp?

Generally, the thermostats have their temperature range stamped on, eg: 71/66 that is, at 71C the switch contact is made and at 66C the contact "drops out" such that the fan would turn on at 71C, then keep going until the water temp reduced to 66C.

You can check the thermoswitch out by immersing the switch into a cup of water with a thermometer, that you can use for a stirrer, then add hot and cold water to check the operating range.

Best to stay with the standard range thermoswitch.

Bye, Peter B.

Cheers Peter