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.
What I wanted to do was put the new Thermo Bob 2 on, but I wasn't sure it was going to fit underneath the IMS tank. I contacted Watt-man and asked.
Sure enough, it won't. Underneath the IMS 10 tank there is about 3/4" of clearance between the thermostat housing and the tank. Bill told me the Thermo Bob 2 housing is one inch thick.
He suggested that I might try a Thermo Bob 3, which he originally designed for the Ninja 250 and which is used on snow machines and such like that.
He very kindly set me up with this kit:
The only thing special about this kit is that he didn't install the bypass hose fitting and added a 90° and 45° fitting so that I could fine tune the bypass hose placement.
I'm going to try placing the TB3 where the current bypass fitting is...
...and put the bypass fitting where the original Thermo Bob was.
Since this will be regulating the cooler coolant coming out of the bottom of the radiator Bill has installed a 185° thermostat.
The TB3 has a port in it for a coolant temperature sensor. I've ordered the proper sensor from Trail Tech and will install it. It will be interesting to see the comparison of the temperature at the TB3 vs the temperature at the head and the timing of those temperatures. The sensor should be here tomorrow.
Working at the Speed of Tom™, I should be playing with this next week.
Wow, excellent timing; I was just about to order two Thermobob 2's for my KLR's and one of them has the IMS tank. Is your bike a Gen1 or 2; mine is a Gen1 with the IMS 6.6.
Installing the TB3 into the lower hose, with the 185 'stat is basically what Watt-man does for the Versys 650.
My friend Mike is very pleased with his Versys 650 Thermo-Bob.
Mike may give us a Versys/Kawa. oil sample to compare to KLR's, yet this year.
It appears that I have 1 1/2" between the stock t-stat elbow and my tank so fitment of a thermobob 2 on a KLR using the 6.6 gal IMS tank shouldn't pose a problem.
In the second photo it appears that the bypass line is tapped into the t-bob housing up stream of the thermostat. Am I just not squinting at the photo right?
Are you going to install the housing "backwards" so the bypass side can flow continuously without passing through the thermostat and the radiator water enters what would normally be the discharge side of the thermostat?
Yes. Coolant will flow out of the head through the upper radiator hose. The bypass fitting is in that hose. The bypass hose will run down to the TB3 and around the T-stat, which is a 185°F unit.
When that bypassed coolant reaches the 185°F range the t-stat will open, allowing full flow of coolant from the bottom of the radiator to the pump.
I was asking for the benefit of those following your path. It would be easy to in inadvertently pipe it using the "standard" inlet/outlet arrangement.
Your arrangement is a clever one for those of us using the IMS 10.7 gallon tank. In my case I had already install a bypass line from a fitting tapped into the head. So, when Watt-man came out with the 195 deg. t-stat that fit the stock housing, I just popped one in and my big tank fits fine. With the advent of the t-bob3, I recommend your approach over mine.
If I had more confidence in my ability to drill and tap where there is no room for error I might have gone your route. My work area is called the Shop of Horrors for a good reason.
I cannot claim cleverness for this; it was Watt-man's suggestion. The sketch above is his.
New hoses (to replace the spares that are lost somewhere in the Shed of Horrors) are supposed to be here tomorrow.
So, Watt-man did/does offer a 185 thermostat for the Original T-Bob. It is used in the Versys kit, which uses the backward flow pattern. T-Bob in the lower hose.
So with a 185 stat in an original housing, couldn't one just trade locations of parts?
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.
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.
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.
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°.
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.
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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