KDXRIDER.NET

Guys, I've looked through many of your posts and have done much of what you recommended, but my '97 KDX220 continues to overheat terribly. We went out last Sunday (Stonyford in NorCal, high 60's, low 70's, 1,500 to 5,000 ft, beautiful day albeit a little dusty) after I just completed rebuilding my top end. Weisco Piston & Rings, V-Force Reed Block & Reeds, FMF Gnarly Pipe & Q'Series Silencer. New Gaskets all the way around, fresh 50/50 coolant (water & anti-freeze), with Redline's Water Wetter thrown in for good measure. I am running the original stock radiators (which are in decent shape, slightly tweaked, don't leak and appear clean inside) w/original fins (I took my Devol protectors off some time ago to try and improve airflow). I have a 1.6 BAR(?) radiator cap and had to put a safety string on my overflow bottle's cap, since it blows off regularly on long uphills and I am tired of buying replacements. I've checked the overflow tubes for blockage and even bored out the overflow bottle's input and output tubes to relieve back pressure. Per usual the bike started blowing coolant early on in the day, to the point I had to add water not more than 10 miles into the ride. Later in the day, it seemed to calm down and we were able to get a total of 40 miles under our belts before calling it quits. Honestly, I have not yet taken the radiator cap off since we returned to see how much, if any water is left. We are going out again this Saturday and before we go I plan on checking the torque on my cylinder & head bolts and replacing the coolant w/straight water + water wetter. Long term, I am thinking about buying some aftermarket radiators, but considering the age of the bike, I may be better off buying a new one. But I understand Kawasaki no longer offers the KDX and with the exception of my overheating problem, I LOVE MY BIKE! Any thoughts and/or suggestions? Thx, Mark

Check your timing. I don't think you mentioned if the bike was new when you purchased it but that's what I would be looking at among other things. Jetting is another.

Also, I would buy another Radiator cap. Just because you have a new one on it... doesn't ,mean it is a good one.

I think Colorado Mike had the same issues and it was resolved with a new KX500 radiator cap.

Thanks for the ideas. I just finished working on it and realize the radiator cap is 16 lbs, not 1.6 BAR. I will get a new one tomorrow. Plus I read the Water Wetter bottle and they don't recommend running straight water + water wetter. Finally, I will read the manual on how to check the timing. I bought the bike new, but you never know ... Thanks again, Mark

yup.

mine is tight now.

If that doesn't do it check your impeller seals. I think the biggest problem with these things is the system not pressurising. If you're at 10,000' the water will boil out at a very low temp, 193° actually. at 12,000' you're at 189°. You just gotta keep pressure in there to keep the water from high-tailing it out as soon as it can.

CM -- any particular year for the KX500 cap?

The last ones they built will work. (2003?) Keep in mind though that the stock cap even for a KX500 was a 1.1 , the 1.6 is an option. get the 1.6 one.

and also, my cap is meant for a Honda CRF 450. they're pretty standard.