[Biggs3118]

Long explanation, please forgive me.

It finally got cold here and I've been riding the highway in 40degF temps the temp gauge would 'barely' see 1/4(I don't like that, plus it's not good for the engine to run that cool).

I'm from AZ and ride when it's 110degF so ya, 40degF is 'cold' for me. I also have a lot of scare tissue from tons of surgeries that's blocking blood flow.

By the time I make a quick stop at a store and return to the bike it would be nearly completely cooled down and I'd have to wait for it to register on the gauge again before hitting the road(I always let my bikes warm up). Note: I do NOT have a Tbob on this bike.

I decided to experiment with a typical mod that is often seen in the 'big rig' community during cold weather. After making some basic BTU calcs I came up with this, it blocks exactly (1/3) of the radiator surface area.

I realize it looks basic but keep in mind it's experimental. There is a reason it's on the bottom.

This simple mod allows the bike to now come up to 1/2 on the temp gauge when riding in the cold (where I like it to be for efficiency sake among other reasons) Same goes for hot summers, I like it to run right about 'half' on the gauge.

The engine obviously maintains it's heat longer after shutting it off to run into a store. I haven't had to wait to let it warm back.

Coming up the mountain on the way home it still sits at HALF on the gauge.

It's not good for the engine to be loaded hard while running 'too' cool.

I'd also like to point out that I don't even have to 'top off' the oil between changes on this bike(doesn't burn a drop) even after 6hrs of 4500-5000rpm on the highway.

Not trying to create drama, just thought I'd share my 'simplistic' solution. If it works for 'semi trucks' it could too work for the KLR.

Let me be clear, I still believe having a Tbob is the ideal setup. I just don't have one at this point. I also believe that 'always' letting the bike 'warm-up' before getting on it has protected this engine.

Thanks for reading my long post, best wishes and ride hard/often.

 

[Fepony]

Sometimes I have to do the same thing with my diesel trucks

 

[R41]

Duct tape works too. And I've got a T-Bob.

 

[Timlang60]

This is a great hack - even a couple of strips of duct tape would do in a pinch! I'll just say I have a 'Bob installed and ~3 weeks ago I made the 210 mile trip from Mayo Clinic to home at ambient temps that started at 34° and ended at 28°, and the temp guage never budged off of 190° indicated. Except for extended stops in jammed up traffic, I see the same during temps into the mid/upper 90s during the summer - the temp comes up to low operating range while I'm strapping on my helmet and putting on my gloves, it's at normal temp within a mile and a half of easy riding, then it doesn't budge from there except as mentioned above. If I ever buy another KLR, it'll have a t-bob installed within days.

 

[SirMarksAllot]

….at ambient temps that started at 34° and ended at 28°, and the temp guage never budged off of 190° indicated. Except for extended stops in jammed up traffic, I see the same during temps into the mid/upper 90s during the summer….

+1^^^. Just did about 600 miles in 28-48F and temp was 195 except in traffic. Didn’t burn a drop of oil on my 2016, and rode it like a rented Mule 🤣🤣

 

[Hawkerjet]

I have the coolant bypass installed aka Thermo-Bob.

My usual M.O. is to ride once a week and pick the best weather day. This is a big benefit of being retired.

At temps much below 50 I usually find something else to do instead of riding. I'm just not much of a cold weather rider.

It's called cherry picking. 🍒

 

[a4twenty]

It finally got cold here and I've been riding the highway in 40degF temps the temp gauge would 'barely' see 1/4(I don't like that, plus it's not good for the engine to run that cool).

you may not like it or think that its not good for the engine but that is exactly how the engineers at Kawasaki designed the engine. they could have chosen a different thermostat in the beginning or at anytime over the last few decades but stuck with the 165F thermostat. they could have also installed a different gauge to put the factory chosen tempurature were it visually makes people feel better, they didn't.

luckily they fixed this with the gen 3 by removing the tempurature gauge.

 

[Klrian]

If people think the t-Bob is from backyard hack hoping to make a dollar I suggest they Google Bill Watson twin turbo mustang on the cover of hot rod magazine. Also featured in about 2001 in Motortrend magazine. Ive met Bill a couple of times and he is as nice a guy as you will ever meet, much like Eagle Mike. No ego just genuinely nice.

 

[DPelletier]

you may not like it or think that its not good for the engine but that is exactly how the engineers at Kawasaki designed the engine. they could have chosen a different thermostat in the beginning or at anytime over the last few decades but stuck with the 165F thermostat. they could have also installed a different gauge to put the factory chosen tempurature were it visually makes people feel better, they didn't.

luckily they fixed this with the gen 3 by removing the tempurature gauge.

Engineers aren't infallible; 165 deg. is too cold. though raising the minimum operating temps isn't the primary benefit of a Thermobob. I do agree with removing the temp gauge.

Dave

 

[Biggs3118]

Engineers aren't infallible; 165 deg. is too cold.

Ain't that the truth. IME 195 is the 'sweet spot'.

 

[KLR-Mule]

I have the coolant bypass installed aka Thermo-Bob.

My usual M.O. is to ride once a week and pick the best weather day. This is a big benefit of being retired.

At temps much below 50 I usually find something else to do instead of riding. I'm just not much of a cold weather rider.

It's called cherry picking. 🍒

I take my bike OUT of hibernation in the winter….if you call it winter here in northern Cali. October-May is when I do the majority of my riding.

When it hits 90F+ in summer months, I park it most of the time. I’ve ridden in 110F once, and it was absolutely miserable.
40-60F is puuuurfect 👍

 

[Biggs3118]

visually makes people feel better

That's hilarious, as if it has anything to do with visual pleasure....

 

[Timlang60]

Engineers aren't infallible; 165 deg. is too cold. though raising the minimum operating temps isn't the primary benefit of a Thermobob. I do agree with removing the temp gauge.

Dave

I think you're wrong. Engineers ARE infallible, that's why no KLR ever burns oil, and you don't ever have to check it! 🤣

 

[StarfuryTH]

I approve!

Indeed, 165F is too cold for a gas engine. For optimal combustion, you actually want the engine to be as hot as possible without causing damage. Practically speaking, this is generally ~195-210F, depending on the cooling capacity of the cooling system, engine component compositions, etc. ~230F is where a lot of engines start risking damage due to warping components. Obviously you want some overhead between normal running temp and "danger zone", hence 195F thermostats being very common.

165F thermostats were an old hot rodder solution to inadequate cooling systems that couldn't keep up with heat output at full load; the extra overhead between running temp and harmful temps allowed you to run flat out without overheating the engine, and to shut down without heat soak doing the same. The downside to running this cold is very poor combustion resulting in reduced power and lots of carbon buildup in the cylinders.

I need to rig up a block plate for my radiator now that it's nice and cool outside. Thermobob is on the to-do list, but I'll probably wait until spring rains and valve adjustment time.

 

[pdwestman]

engine component compositions, etc. ~230F is where a lot of engines start risking damage due to warping components.

I'll disagree with that statement.
The engine metals are perfectly safe up to 300-350F+ as long as the engine oil stays below about 250-275F in the sump.
Most air-cooled motorcycle engines operate in the 275-350F cylinder head temp range very frequently.
Liquid-cooled engines need pressurized Coolant/Antifreeze to stay below the boiling point of the coolant, to prevent hot spots from developing. Once any hot spot develops the whole system can spike quite quickly.

165F thermostats were an old hot rodder solution to inadequate cooling systems that couldn't keep up with heat output at full load; the extra overhead between running temp and harmful temps allowed you to run flat out without overheating the engine

I'll disagree with that statement also.
A 165F thermostat can not compensate for too small of radiator or too slow (or too fast) of coolant flow or too slow of air flow, be it in a KLR or any hot-rodded engine!

 

[Texduramax]

New here with a newly purchased 2022. In attempts to decipher all the info. being feed through the fire hose, I've come up with a question about the operating temperature that I'm sure has been asked a 100 times, so please be patient if it has.

In regards to the T-Bob, wouldn't a simple change of the thermostat to one that operates in a higher temperature range (180 degree F), not solve the cold operating temperature problem?

 

[DPelletier]

New here with a newly purchased 2022. In attempts to decipher all the info. being feed through the fire hose, I've come up with a question about the operating temperature that I'm sure has been asked a 100 times, so please be patient if it has.

In regards to the T-Bob, wouldn't a simple change of the thermostat to one that operates in a higher temperature range (180 degree F), not solve the cold operating temperature problem?

yes, but that's not the biggest issue; the biggest issue is the cold shocking of the cylinder which happens regardless of the thermostat temp rating and regardless of ambient temps. Read Bill's (Watt-Man's) testing data here: http://watt-man.com/wp-content/uploads/2021/01/Art_TB_Testing.pdf the one on the bottom of page 4 is the most enlightening IMO.

Dave

 

[Biggs3118]

New here with a newly purchased 2022. In attempts to decipher all the info. being feed through the fire hose, I've come up with a question about the operating temperature that I'm sure has been asked a 100 times, so please be patient if it has.

In regards to the T-Bob, wouldn't a simple change of the thermostat to one that operates in a higher temperature range (180 degree F), not solve the cold operating temperature problem?

In short, no. This is because the OEM cooling is not a bypass system. It deadheads behind the thermostat until it opens whilst allowing the water in the radiator to 'over cool' which then 'shocks' the cylinder once it opens and allows coolant to flow. That's the basics but I think you get the idea. Best wishes

 

[Biggs3118]

Haha, Dave beat me to it.

 

[Texduramax]

yes, but that's not the biggest issue; the biggest issue is the cold shocking of the cylinder which happens regardless of the thermostat temp rating and regardless of ambient temps. Read Bill's (Watt-Man's) testing data here: http://watt-man.com/wp-content/uploads/2021/01/Art_TB_Testing.pdf the one on the bottom of page 4 is the most enlightening IMO.

Dave

That's the basics but I think you get the idea. Best wishes

Roger. Makes sense.

Thanks for clarifying