S1: Spare Thermostat and O-ring(s) for Thermo-Bob Original, Thermo-Bob 1

This fits the “Thermo-Bob Original” (sold from 2007-2014) and “Thermo-Bob-1″ (still available today) products.  These larger Thermo-Bobs have a 6 bolt pattern and install IN the coolant line.  The rubber ring on the thermostat is approximately 1.5” in diameter.  If you are looking for a spare thermostat for a Thermo-Bob 2, 3, or 4 that use a smaller, 1.25 inch diameter rubber, you want an S2 or an S3.

195°F is standard in all KLR650 Thermo-Bob kits because they are controlling the coolant temperature headed exiting the engine.

180°F was standard in all Versys, KLR250, KLX250s and KLR600 applications as those were controlling the coolant temperature entering the engine.  This particular ‘stat was also standard on Rotax applications.  This same temperature was also standard when we used this larger thermostat on snowbikes in the 2013-2014 timeframe.

O-rings that come with your purchase:

• Large Diameter, skinny o-ring comes with all kits.
• All KLR and KLX applications will also receive the Small Diameter, fat o-ring as well.