Removing the Thermostat. Yes or No

I have a 2001 XR650r. I have been reading some places that if i remove my thermostat, the bike will not over heat as fast as it does. Is this true?? The only mods i have on my bike or Jet Kit, uncorked, 200 Watt stator, and radiator cap is bigger but not sure what size.


I wouldn't remove the thermostat. A thermostat is there to block/allow flow at certain times. When it's blocking coolant the radiators have a chance to do there job with regards to airflow. Vice-versa in the winter months. No thermostat=consistent flow of hotter coolant in and out of the engine quickly therefore not allowing the coolant to sit in the radiator and cool down. I've substituted my stock thermostat for an SRC high-flow one, with the SRC cap and engine ice. The bike is uncorked which is the first step to stopping the "boil-over". I use the coolant overflow bottle as my gauge. When it gets above the high mark it's time to boogie. I haven't had an issue since, and I ride tight New England trails 1st and 2nd gear.

I've followed the t'stat debate for sometime now. The argument that without the stat in place causes the coolant to pass thru the raditor to quickly and thereby not cooling off enough makes me think that if the coolant passes through the engine at this accelerated rate it would also not be picking up as much heat to start with. Therefore it is likley a non issue. If you catch the way I'm drifting. IMHO


Mine is removed except in the cold months. Takes too long to warm up without one in the winter.

I was going to take mine out but decided not to because it fails open. So I don't think it will be an issue for me.

Based on my experience with cars, ditching the t-stat shouldnt make an engine overheat as long as the cooling system is adequate. I have never heard of coolant not being in contact with the rad long enough to reject sufficient heat, at least not with the volumes a typical water pump can move. The issue is more of the engine never coming up to operating temp. This leads to accelerated wear, poor economy, and buildup of sludge and condenstaion.

Just get a cooler 'stat and, what, a 1.6 Kg cap?

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