KDXRIDER.NET

2005 KDX 200 is new to me.

I just bought a Trail Tech Vapor computer. Among many features (speed, odo, rpm, etc.) it has a thermocouple that goes inside a radiator hose to read engine coolant temperature.

But I can't figure out which hose to cut and install the thermocouple in. There's a hose going between the water pump and the bottom of the right side radiator. There's also a hose between the bottom of the left radiator going to the top of the cylinder head. (My infra-red temp gun doesn't seem to be much help.)

Can anyone tell me which way the coolant flows? Which hose has the hot coolant and which one the cooled coolant?

THANKS!

I spliced the coolant temp sensor for my trail tech computer in the rad hose that goes from the top of the one rad over to the other.

Tyl3r wrote:I spliced the coolant temp sensor for my trail tech computer in the rad hose that goes from the top of the one rad over to the other.

Ok. But that might not be the hottest coolant since it's gone through one radiator already. ? Thanks for the reply.

Tyl3r wrote:I spliced the coolant temp sensor for my trail tech computer in the rad hose that goes from the top of the one rad over to the other.

Same for me..... in searching around I've seen where many others put it in the same spot. Just cut out about an inch of hose from the middle of it and it fits like a glove. Just make sure the wire is pointed down..... it's still a tight squeeze in there once the tank is on

When I did it I used the hose coming from the top of the head to the left (as sitting on the bike) radiator. It worked great and that is where the coolant is coming out of the engine.

SS109 wrote:When I did it I used the hose coming from the top of the head to the left (as sitting on the bike) radiator. It worked great and that is where the coolant is coming out of the engine.

Ok. That's what I needed to know. THANKS.

When I was reading this yesterday I was trying to think of the direction of coolant flow, because I didn't know either. I did a quick google and came across this, and thought it made sense:

http://www.assfaultjunkies.com/showthre ... olant+flow

They are saying it flows the opposite direction (but then again they aren't a KDX specific forum haha). It made more sense to me that the coolant would flow down around the head and piston from the top where the most heat is generated (water enters at the hottest point to maximixe the heat transfer there) and the water pump would provide the pressure to push the coolant back up into the rads. But then again, I could see how on a car, the water goes into the top of the rad, and out the bottom, right? so that would be the opposite of what I just said? haha what is right... I want to say that I feel the water pump side is the hot side... how to know for sure?

The water pump outlet is the 90° rubber hose that goes up and turns to the cylinder. Pumps are fed through the center of the impeller and then the liquid is slug out from the outer diameter.

david wrote:The water pump outlet is the 90° rubber hose that goes up and turns to the cylinder. Pumps are fed through the center of the impeller and then the liquid is slug out from the outer diameter.

Yup!

Here is a diagram showing how a mechanical impeller type water pump works. So, the top of a KDX's head is the outlet for the coolant.

Understood, coolant flows out of the RS radiator, into the pump, into the cylinder, out the head, into the LS radiator.

Thanks for clarifying, good to know.

Tyl3r wrote:Understood, coolant flows out of the RS radiator, into the pump, into the cylinder, out the head, into the LS radiator.

Thanks for clarifying, good to know.

Thanks everyone for your help. I know now to put the thermocouple inside the left side hose.

This is a great forum!

Norm