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Anybody have and recommendations to keep my Kdx220sr running cooler. It has aftermarket radiators which I believe are 2 core. It has a small computer fan which comes on the same time as the temperature warning light. Temperature here is 36 degrees Celsius and a lot of my riding is barely first gear. I think an upgraded fan would be an option. No idea if 3 core radiators exist or fit, I also had an idea to buy CPU cooling fins and strap them to the cylinder, kind of like semi air cooling

I would look at what hard enduro guys are doing, then copy it. Maybe more fans / bigger fans?

No temp lights in the USA.

Check into water wetter, I think in the states you can find brands like red line or engine ice. larger radiators or always on fans. May also want to try and find a slightly higher pressure cap and make sure your overflow tank is plumbed correctly.

36! That’s plenty toasty.

Does the coolant boil out with existing setup, or do you just wish that the temp light would stay off?
If the light comes on and then goes away fairly soon after the fans come on, I would think that might be ok as long as your not losing coolant.
My buddy on his KTM has the fans come on during long hill climbs... then it turns off after we level out a bit, and that can happen to him at 36F.

Sorry I don’t have KDX specific knowledge.
This is how I got Jeep Cherokee trail rig to stay cool: bigger fans / extra fans, hard wire so they run em all the time w/ manual switch in series to turn them off when not needed. Or add bypass in parallel to your auto control to turn them on as much as you like. Not sure if your controller is self contained or has external wiring you can tap into.

(+ I had to add timer to run the fans 4 min after I shut off to help get hot air out of engine bay, so the fuel rail wouldn’t vapor lock.... )

I can only make it stopping at 2 traffic lights before the fan and light comes on, out on the open road it still stays on, stop for a break and the fan is off again but back on as soon I am at the next set of traffic lights. On the tracks the light and fan is constantly on, you can feel it getting hot but I stop where I can at a stream and splash water on it. Its boiled over a few times but I've learnt I need to stop more frequently. As it gets hotter it runs worse because it runs richer and it's already too rich

Watter Wetter and a KX500 rad cap will do the trick.

Have you checked to make sure your water pump impeller is in good shape and tight?

SS109 wrote: 11:13 am Mar 11 2020 Have you checked to make sure your water pump impeller is in good shape and tight?

This is a big one. Some companies make aftermarket ones with bigger fins that’ll move that coolant more efficiently

You guys have great ideas (these might also help my jeep).
Hope it can cool your SR.

If its getting that warm on the open road you need to take a good hard look at your cooling system health. Might be good idea to pressure flush the cooling jacket and lines and check your flow rates.

I am not seeing anything in this thread saying what the actual engine temperature is. Your switch to activate the light and fan may be set lower than necessary. I would instal a gauge in the cooling system so you know actual temperature.

IIRC, SR models are equipped with a thermostat. If so, it may be restricting coolant flow, so you might consider removing it. Our KDXs here in USA don't have them.

Doesn’t seem right to run that hot just in traffic. I’d take a detailed look at my cooling system. Heck it could be something as simple as a partially blocked line or passage somewhere. Make sure the system as designed is working properly before looking for mods.
Just my $.02.

Yeah, check over the stock setup before looking for aftermarket solutions. If it does in fact have a thermostat that would be where I would start.

doakley wrote: 04:51 pm Mar 11 2020 Doesn’t seem right to run that hot just in traffic. I’d take a detailed look at my cooling system. Heck it could be something as simple as a partially blocked line or passage somewhere. Make sure the system as designed is working properly before looking for mods.
Just my $.02.

In traffic is one of the most demanding settings for a motorcycle from a cooling system standpoint.

Water pump has been fully rebuilt, when I bought it from the previous owner I saw the radiator cores were blocked so had the welded tanks taken off and cleaned out the cores myself. Buying a gauge would be a good thing so I can know the exact temperature but kind of sure the engine is cooking as when I splash water in the streams you can see the sizzle. I haven't tried water wetter but can't imagine that would help, I think I need a 50 percent cooling upgrade, not just a slight improvement. I'm using an 1173l needle and 135 main jet. Slightly rich down low but feels lean in the midrange so might be a slight cause of the overheating

I don’t think it’s your jetting. I’m still betting on something in the cooling circuit. Now that I read the rad was blocked and the water pump was “rebuilt when I bought it”, I’m leaning towards the cooling system even more. Good luck tracking it down.

If it will run with the choke on or part way on. That can simulate richer jet. Or block the snorkel / cover the air box if it’s uncorked. That might help tell you some info easily if lean condition is contributing.

Water pump was rebuilt by me with a new impeller (not when I bought it). Won't run at all with the choke on but needs it to start. I'm running a snorkel from a kawasaki boss 175 which is about 10 percent bigger than standard. ( I WAS GOING TO DO A WRITE UP ON IT AS HUGE IMPROVEMENT OVER THE OPEN AIRBOX) Was running a 142 main jet but changed to a 135 a few days ago. No change in power but smokes less with the 135. It doesn't have a thermostat. I've been through the whole cooling system quite meticulously, I'm wondering if the Chinese radiators are not as efficient as the OEM ones. With mine having the High out put stator I might try running 3 or 4 fans.

This is my Chinese radiator and the second photo is OEM radiator from a Klx250. Even though they are of very similar dimensions the Chinese radiator has 9 cores and the OEM has 17 cores. This would make a huge difference towards cooling efficiency. Can anybody confirm how many cores the OEM Kdx220 has

Any possibility that combustion gas is passing into water jackets via failed deterioated head gasket? This was a common failure mode on the Subarus I worked on for years. Always presented as a cooling system due to lack of white smoke but 9 of 10 were head gaskets. There was a chemical check to put on top of radiator cap opening and fluid would change color if combustion gas was present.