CR4A Thermo-Bob Kit

We’ve seen our share of CRF450s used as a snow bike, and in those applications, the lack of factory cooling system control leads to cold coolant temps.  There is no factory thermostatic control, so coolant temps can vary widely, then these carbureted bikes have inconsistent jetting.  The Thermo-Bob 3 is a machined aluminum housing with a 180°F (82°C) thermostat inside, and 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.

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.

A full technical write-up when used on a Kawasaki KLR650 can be found here.