Dear Mr. Know-It-All,
I recently picked up a 2019 KTM 300XC-W and had a question regarding the thermostat: run it or replace it with a straight-through hose kit?
Vern Hatch

To be quite honest, Vern, we have had no issues with our long-term KTM TPI machines, which are running the thermostat. The thermostat assists the engine in getting it up to operating temperatures in extreme cold, and removing it will not allow the engine to get up to the correct operating temperature. The KTM XC two-stroke does not run a thermostat since it’s designed for high flow, so the main benefit of the bypass hose kits (basically, eliminating the thermostat kit) is to increase the flow and reduce the engine temps.

My sage advice is this: run the thermostat based on your riding environment. If it gets frigid, it lets the engine warm up properly and this is important. If your riding areas offer a more temperate climate, you should have no drama by removing the thermostat.

One final note: I do recommend changing out the stock hoses. They are flimsy, and the silicone-based replacements are more durable. Companies like Samco offer silicone hose kits that retain the thermostat or eliminate it.

300KTMMr KIAMr know-it-all