KT4F Thermo-Bob Kit

Even though some of these bikes have a factory thermostatic control, coolant temps can still vary widely.

The non-thermostat bikes obviously run cold in the snow – but even the factory thermostat bikes still run cold because the factory thermostat is rated at 158°F, and doesn’t totally close off radiator flow when below rated temperature.  This is because there is a large bleed hole in the thermostat that is fine when used as a dirt bike, but on a snow bike it becomes an issue as you just can’t afford to send that much coolant flow through the cold radiators.

The Thermo-Bob is a machined aluminum housing with a 180°F (82°C) thermostat inside.  This modifies your cooling system to operate like automotive systems have for decades… keeping coolant flowing all the time through the engine, but not through the radiators until it is up to a selected temperature.

You can see by the two asterisks in the image that the factory thermostat bikes will require you to purchase a KTM hose that will allow you to remove the factory plastic thermostat housing, 158°F thermostat and lines, and replace it with the machined aluminum Thermo-Bob.

There is also a threaded port in the Thermo-Bob 3 that will accept aftermarket temperature gauges such as the KOSO or TRAIL TECH 1/8-28 BSPP temperature sending units.