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Discussion Starter #21 (Edited)
I had the original T-Bob totally bassackwards.

Fixed it.

The original T-Bob won't fit at the lower location because it has to go in backwards. That puts the fat, flat end on the down side where it won't fit between the hose at the front of the engine and the headtube.

Tom
 

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Discussion Starter #22 (Edited)
While I'm doing this because it's fun, interesting, and keeps me out of the bars, the real intent of this is for someone who has an IMS 10 and no T-Bob.

This is an option for such a person, as the T-Bob 2 won't fit. Installing the T-Bob 3 in the lower hose fits better, overall, than the original does in the upper hose.

Using the original T-Bob backwards in the lower hose is not a part of the equation.

Tom
 

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Discussion Starter #23 (Edited)
The new hoses arrived, there was a round tuit on the counter, and the planets were aligned.

First thing, clear the front of the engine:



There were a lot of fits and starts, trying to find the perfect position and the perfect hose cuts, but I finally wound up with a good mock-up and pulled it out and built this, working on getting all the hose clamps correctly positioned for easy access and non-interference:


Installed:


Functionally it works identically to the original Thermo Bob.

It fits really nicely and doesn't touch anything. Should be good to go.

Tom
 

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Discussion Starter #24
It took a while, but I finally got a 1000 miles on the 195° thermostat.

I have ridden in 25°-30° with snow, mid 30°s clear and dry, 40°-60° with rain, and 55°-70° clear and dry.

The temperature at the T-Bob is always ~188° and the head temperature is rock steady at what looks like between 215° and 220°. Never varies.

Tom
 

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Good to hear that Tom.
And your engine oil temperature at mile 20 is usually what??

Inquiring minds wish to know.
 

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Discussion Starter #26
It depends.

The oil takes forever to heat up.

In 70° ambient with the Poor Man's "Block Off The Engine" the temp will be up towards 195°-205° after 20 miles and it will finish off at 215° after about 30.

In 50° ambient in might only be up to 180° after 20 miles.

Without the BOTE mod it takes a lot longer, of course.

I tried to judge how long it took to get up to a stable temperature on the last trip. It seems that a half hour of 65-70 mph will do it, and the final temperature depends on the ambient conditions.

Running up the Grapevine at 30-40mph (max for conditions) I watched the oil temperature drop from about 185° (about 50° ambient in the rain at the bottom of the hill, 65mph) to 150° (25°-30° and snowing as I went up the grade). That drop occurred in about 5 miles.

These are rough numbers from recollection, as I didn't specifically look into this. I remember being surprised that it took as long as it did.

I need to find a way to elevate and stabilize oil temp, keeping it over 200°.

Tom
 

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This is Half of the reason that I do not ride my KLR the 1.1 miles to and from work every day! My pick-up has a proper Positive Crankcase Ventilation system on it. No Milky OIL. Normk is working on this issue!

The $400 exhaust system is the other Half of the reason! vs $70-$100.00 for the pick-up.
 

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I am enjoying reading how you guys really get stuck into your bikes!

This is Half of the reason that I do not ride my KLR the 1.1 miles to and from work every day! My pick-up has a proper Positive Crankcase Ventilation system on it. No Milky OIL. Normk is working on this issue!



The $400 exhaust system is the other Half of the reason! vs $70-$100.00 for the pick-up.

(British humour warning - following comments made 'tongue in cheek')

You not tempted to walk the 1.1 miles? Lots of benefits:
- engine at full working temp within 2 blocks
- exhaust system good for life of 'vehicle'
- exhaust gases able to flow freely (and colleagues appreciate these being burned off prior to arrival)
-daily operation positively extends 'vehicle' lifespan
- $30 annual budget for 'tyres' needed
- opportunity for walk through coffee on route
 

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Dang, that's a lot of hose clamps!
I agree.

I've spent years, ~19, designing and working on Multiplex hydraulic control systems for use on subsea BOP stacks and for the sake of reliability, you always strive to minimize the quantity of potential leak paths on a hydraulic control system. I'm in the minority when I say this, but the advantages of the Thermobob do not offset the cost of the system and the inherent increase in failure points.

But if you enjoy adding stuff to your KLR, you could do far worse than installing a Thermobob. So, if it's caught your eye, go for it. But the Thermobob should be way down on the list of things you need to do to get that bike up to scratch.

Jason
 

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I agree.

I've spent years, ~19, designing and working on Multiplex hydraulic control systems for use on subsea BOP stacks and for the sake of reliability, you always strive to minimize the quantity of potential leak paths on a hydraulic control system. I'm in the minority when I say this, but the advantages of the Thermobob do not offset the cost of the system and the inherent increase in failure points.

But if you enjoy adding stuff to your KLR, you could do far worse than installing a Thermobob. So, if it's caught your eye, go for it. But the Thermobob should be way down on the list of things you need to do to get that bike up to scratch.

Jason
Well, I'll defend the use of 6 additional hose clamps to allow the use of a proper radiator by-pass system to bring the ENTIRE engine temperature up to a more 'modern' 195F+, as quickly as possible.

I installed my Thermo-Bob shortly before I began my engine oil flow alterations. Because I realized the potential 'benefits' of higher / more stable engine temperatures, than the stock 160F, with extreme fluctuations.

But if one wasn't ever going to install an IMS 10 gallon fuel tank I would suggest that one should use the Thermo-Bob 2.
 

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Well, I'll defend the use of 6 additional hose clamps to allow the use of a proper radiator by-pass system to bring the ENTIRE engine temperature up to a more 'modern' 195F+, as quickly as possible.
Paul, with all due respect, you missed a couple of potential leak paths: the NPT fitting; the SAE o-ring fitting on what appears to be a temperature transducer; and the four-bolt o-ring connection on the thermostat housing.

I agree that there are compelling reasons why there may be benefits to adding the Thermobob to the KLR cooling system. But those benefits are difficult if not impossible to measure. And if you can't quantify the benefits, then in my mind it's not worth the added complexity.

Please note that I don't look disparagingly at folks that want or have a Thermobob. Notably all the respected long-standing members of this forum and other KLR forums have them. And like I said in a previous post, there are much worse modifications you could make to a KLR. :smile2:

Jason
 

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Jason,

Though I don't have your background, I had similar concerns about the added risk of additional leakage/failure points. I've gone to some effort to reduce/eliminate all known weak spots and problem areas from my KLR's so it was a concern for me. After careful consideration and review of all available data, I decided (right or wrong) that the added risk of leaks was more than offset by the benefits afforded by the Thermobob set up and the more stable cylinder temperatures. I'd note that both the advantages of the T bob AND the increased likelihood of leaks due to the additional joints is impossible to quantify.

In some ways this reminds me of the argument from the DR and XR guys that thier bikes are superior due to the lack of liquid cooling and associated parts/increased risk of failure....while the complexity of liquid cooling does add failure points, I believe that neither of those bikes approach the KLR's potential longevity due to it's far more stable engine/oil temperatures....especially with a thermobob.

As always, thanks for your intelligent and thoughtful posts and opinions.

Cheers,
Dave
 

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Yea I have to agree. The benefits far outweigh the risks of having multiple “failure points.” It’s just a simple motorcycle engine from the 80’s.... it’s not like we’re screwing around with some new modern day automobile cooling system.
 

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Here's a picture of my Thermo Bob Original in the usual place...It works great and always has. It's perfectly positioned and doesn't shake, rattle, or roll. The problem is that it tends to get in the way when I need to get the valve cover off. Since I'm constantly fiddling with stuff, that's a nuisance.
Tom
Taking off the valve cover and drilling out that broken-off bolt allowed me to make two discoveries on my new-to-me 2008 KLR.
1. It has a thermobob and, by the size of it, probably a gen 1.
2. Trying to get the valve cover off, or even just lifting it up and moving it out of the way by a few inches is kind of a pain with the TB being where it is.

I'm contemplating deleting it vs replacing it with one of the smaller gens. A couple questions if you don't mind...

Is there a way to tell for sure what gen it is?

Currently, the bike's temp runs mid level on the temp gauge, goes way up at stop lights, then back down to mid level when the bike gets going again. Without the TB, what would the gauge likely be doing?
 

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I'll recommend that you leave the Thermo-Bob installed, ignore the temp gauge unless the needle is Actually touching the RED-ZONE and remove at least the TOP radiator mounting bolt and allow the radiator & T-Bob to rotate Forward and away from the valve cover & head during valve tappet inspection & adjustments.
 

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Currently, the bike's temp runs mid level on the temp gauge, goes way up at stop lights, then back down to mid level when the bike gets going again. Without the TB, what would the gauge likely be doing?
The Thermobob will not stop the temperature from rising at stop lights; that's normal behavior with or without Thermobob. The fan should start running and keep the temperature needle from entering the red zone at stop lights.

During continuous riding, the temp needle should be at about half scale if a Thermobob is installed. Without a Thermobob the temp needle drops down to just above the lower normal mark on the scale during continuous riding.

Jason
 

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To add to what's been said;

- it should be obvious which thermobob you have; the Original is an inline pce, the Thermobob 2 is a replacement T stat housing; Information, Articles

- functionally they are the same but the 2 is a cleaner install. Whether or not it's worth replacing an Original with a TB2 depends on your budget and how often you plan on having the valve cover off...


The gauge only shows you a small part of the picture with regards to what the thermobob does. Read the "testing results/history" tab on the link above to learn more.
 
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