RX3 Cooling System

[katflap]

Some of my parts arrived to today
1/ revotec (SST8K) self sealing 8mm barb -
My gut feeling is that the internal diameter of 5mm might be too small to gain the full benefit.
Now seeing it close to the bottom hose, I don't think it will squeeze the hose flat as much as i Initially thought, when fitted.

2/ Koso 18mm water temp sensor adapter-
This comes with a water temp sensor, the adapter sensor hole is 1/8 NPT.

My inital plan was to fit the gauge temp sensor in to this adapter. spud measured our gauge temp sensor as M10 with the fine 1.0 thread.
If this is bigger than 1/8 NPT then a larger tapped hole will be need. The boss on the adapter is only 13mm wide so quite tight.
Our temp sensor will require a ground wire attached to the adapter.
I plan on using an after market temp gauge that comes with a 1/8 NPT sensor.

To use the koso adapter as the bottom hose connector would be very tight if not impossible (see picture)

[katflap]

Got my temp gauge fitted today so I can now easily monitor the coolant temp and get some temp readings before and after fitting the by-pass.

Did a quick test, ran the bike stationary until the fans kicked in (81c) then set off.
Average temp whilst riding 60c with an air temp of 22c.

[detours]

Very cool, Kat! Looking forward to the after test and pics of the fittings.

How long did it take to warm up to 81 C, when the fans kicked on?

[dpl096]

Sweet! I'm old school too and prefer actual readout gauges over idiot lights. My preference is still old style needle gauges but I reckon these here new-fangled digital gauges might be acceptable . I'm also looking forward to your findings.

[Juanro]

I must be missing something. If the average temp of the cooling liquid was 60C, that means that the thermostat isn't opening? (Thermostat was 70C?)

[katflap]

Originally Posted by detours

Very cool, Kat! Looking forward to the after test and pics of the fittings.

How long did it take to warm up to 81 C, when the fans kicked on?

Thanks detours, I didn't think to time it but I think it was around 15mins but I was doing other things whilst it was warming. Also I did rev the engine a bit at one point to speed the warming

[katflap]

Originally Posted by dpl096

Sweet! I'm old school too and prefer actual readout gauges over idiot lights. My preference is still old style needle gauges but I reckon these here new-fangled digital gauges might be acceptable . I'm also looking forward to your findings.

I love a good old needle gauge too, but they seem to be quite pricey or at least the ones that gave you a decent temp scale.


Hope to fit the by-pass soon

[katflap]

Originally Posted by Juanro

I must be missing something. If the average temp of the cooling liquid was 60C, that means that the thermostat isn't opening? (Thermostat was 70C?)

No your not missing anything

This Is a bit of an oddity that I hope to discover what is going on.Unfortunately I didn't have time to test my thermostat In a pan of water to see If it is Faulty.

If it turns out not to be faulty, the idea of the by-pass and then eventually a higher rated thermostat should raise the coolant running temperature

[pyoungbl]

I suspect that the thermostat is opening until it gets a slug of cold water, then closes. The hot water that passes through the thermostat gets cooled by a radiator so when it gets to the temp sensor the water has lost some 20 degrees of heat. This is the same hot/cold cycle KLRs had to deal with, thus the thremobob bypass system.

[Juanro]

I see the temp sensor just after the motor output.. this should be the hottest point, and it's -before- the thermostat.

[pyoungbl]

Juanro, in the stock arrangement you are correct. I was talking about Katflap's meter, which is taking information from a sensor he mounted in one of the radiator hoses. Thus, he's getting the temp after it has passed through the radiator. Katflap found that that temp was only 60C even though the thermostat was supposed to open at 80C.

[Juanro]

Yes, I'm looking at the picture he posted... the temp is mounted using the Koso adapter in the hose at the -output- of the motor, even before the stock mounting of the thermostat. I expected to see higher temperatures there.

[pyoungbl]

Oh, looking at the photo I thought the sensor was after the right radiator. I guess I need to take a closer look at my own bike.

[katflap]

Juanro is right about where I position the temp sensor but my photo doesn't show it clearly this one below is better.

I noticed on my ride to work this morning the temp rising from cold quite rapidly then It reached 52c followed by a marked jump to a few degrees less, typically indicating a thermostat starting to open, way too early !

I really need to test my thermostat out of the bike before I go any further with fitting the by-pass. Fortunately I have a new one coming from China soonish , I will check the new one as well.

[Watt-man]

Originally Posted by katflap

I really need to test my thermostat out of the bike before I go any further with fitting the by-pass. Fortunately I have a new one coming from China soonish , I will check the new one as well.

Kat, here is a testing tip: put the 'stats in your test pot of water with the rubber down and the wax housing (the part that says "70C" on it) aimed up so you can see it. Before heating, carefully notice where the wax housing is relative to the surrounding spring support. The operating temperature is that which moves that wax housing only 1 mm. Lots of people would think that it has to move 3mm or so to be "at operating temperature" but that is not the case.