Before, doing the Thermo Bob mod, I did my homework and decided it was needed. All engines are designed to operate at a specific temperature and running below that temperature causes additional wear. I wanted my KLR to reach operating temp as quickly as possible so I installed the Thermo Bob.
Thermo-Bob is a thermostat installed in the KLR's upper radiator hose. It connects to a second fitting installed in the lower radiator hose. When the engine is cold, Thermo-Bob routes engine coolant around the radiator allowing the engine to quickly reach operating temperature. When the engine warms up, Thermo-Bob routes coolant to the radiator to prevent overheating.
This cycle repeats to maintain a near constant 185 degree operating temperature at the lower end of the cylinder. Proper operating temperature reduces engine wear and allows for smoother shifting. For more details on Thermo-Bob, visit
shop.watt-man.com. They are great people to work with and I highly recommend them.
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| Thermo-Bob installed in the upper radiator hose. |
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| Fitting in lower radiator hose |
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| Lower fitting with bypass hose on upper left |
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| Chaffing wire bundle near horn. |
The installation was very simple and straight forward using the instructions printed from the internet. This was my first time removing the gas tank and fairings so that probably took longer than installing the Thermo-Bob. While I had everything apart, I took several pictures of the bike stripped "naked", she looked a lot different.
Two mistakes that you will want to avoid when you Thermo-Bob your KLR. First, run the gas tank to almost empty. My tank was half full which made that monster even more awkward during removal and installation. Second, don't forget to reinstall the coolant drain plug before refilling the cooling system. That oversight on my part created a small mess on the garage floor. But, I had kitty litter on hand to clean it up so it was not really a big deal.
It was nearly dark by the time I finished, but I had to take her out for a ride. It was a cool evening, 51 degrees, but the temp needle stayed solidly in the mid range during the test ride. Two improvements that other guys had noticed from this mod was smoother shifting and better acceleration. I noticed both of these right away and was very happy with how the bike performed.
Overall, the Thermo-Bob mod is easy and well worth the time and trouble. I would recommend this to every KLR rider who is interested in longer engine life without burning oil. The smoother shifts and zippy take offs are also nice. Better gas mileage is another expected benefit, but I have not ridden enough yet to know.
