KDXRIDER.NET

Interesting thought CC, I was surprized at the power of the impeller to drive that much coolant out of the cap hole with just a quick blip of the throttle. Dave04, the coolant is as clean as when it goes in, so I don't think there is a head gasket leak. I changed to a wiseco piston at the beginning of the season. used a new gasket with copper coat sealant. Keep in mind the bike runs great, it's just at low speed, high effort conditions when not much air is passing over the radiators that it blows off. Ski has graciously offered to send me some Evans coolant, so I'm gonna give that a shot. If that doesn't do the trick, I'm gonna look into a lighting coil to drive some little fans. It has been unusually hot here lately. That coupled with the thin air has been making it tough. I don't know how you guys in AZ can stand it. I visit my FIL sometimes in Bullhead city, and I need a spacesuit. It was 127 the day he moved into his new house down there a few years back!

Thanks all,

Hey Mike

The heat here is an acquired taste I still ride in the summer, just go early in the morning or late evening. We can ride almost year around here. I used to work in Colorado part of the year and the cold about killed me Its what you are used to I guess.

You could always run alcohol (methanol) as your fuel...That will cool things down tremendously, and add ~ 8hp accross the band.

I can hear it now.....'I'd like to order a Keihin PWK 360 main jet, a 65 pilot and a GEB needle, please.....'

8 hp?? that would be awesome. I'll try running it on scotch first.

My point regarding jet sizes: Alcohol has about 1/2 the BTU that gasoline has per same volume of fuel. It takes a lot of alcohol (dunno about the scotch part) to run an IC engine..that's why there is such a cooling effect with alky.

That's why racefans love the alky funnys..they can do 3-4 burnouts and still stay cool enough to be competitive on their run.

Well...and funnys are just fun anyway........

Let us know how the Glenlivet works for 'ya!

Maybe a few of these will help! Supposed to be good for 5 to 10 degrees difference!

http://www.rockymountainmc.com/Product_ ... d=00005646

Pro Design Super Cooler, in line water cooler,most models $28.99


Heres another:

http://www.rockymountainmc.com/Product_ ... d=00023267

LC Performance in line Coolant Cooler, Most Models, Gold $24.99


OR maybe some of this!
http://www.rockymountainmc.com/Product_ ... d=00102880

Motul Factory Line Motocool, 1 Liter* $7.99

Motocool's Organic formulation ensures exceptional protection for the latest aluminum and magnesium alloys.
It has an extremely high boiling point of 277°F for greater power and won't freeze until -31°F.

'I'd like to order a Keihin PWK 360 main jet, a 65 pilot and a GEB needle, please.....

LOL! That's probably not that far off!!

That motul coolant looks pretty sweet. Never seen it before. I love every product of their's I've ever used.

Fuzz... Do you use the racing 800 2-stroke oil ?? If so, do you find it spoogy ?? The reason I ask is I have ALWAYS run the 800 in every 2 stroke I've had and found while it seems to offer great protection it also seems to run a little dirtier than say Castrol TTS or similar price range oil. I think it's designed for high revving 125's etc....

Sorry about the hi-jack.....

Yeah, I use the 800 at 40:1 w/ great results. No spooge. Well, my WR is currently spooging, but it's not Motul's fault. I use their 2T gear oil as well.

Thanks dude....

I just read on a KLX site that if the bike is overheating to try a KX500 radiator cap. Maybe that will work... I have no idea if it will fit but proly is a higher pressure cap by a few pounds....

Good tip Vince. I was riding a KX500 today, wish I had checked the cap to see the rating. The thing I don't understand about all this is, the coolant recovery bottle is supposed to umm, recover coolant. Mine is connected properly, the tube coming from the radiator cap is connected to the bottom of the recovery bottle. The top of the bottle has a tube running down to my skid plate so I can see when it spews. I thought the theory was, the coolant in the rads gets too hot, boils out into the recovery bottle, condenses and is sucked back into the radiator. Mine just boils right out and empties onto my skid plate.

I was riding at 13,000' today (stupidly forgot the camera, sorry, it was spectacular) I did not rejet, so the bike should have been running pretty rich, especially since i jetted it rich for 9000' to stave off the boiling. It did the steam locomotive act again during the climb. 5 bikes in our group, all but one were liquid cooled, and mine is the only one that boiled. Obviously there is something wrong with my cooling system, even though the pump seems to move plenty of coolant. One hint is that I've noticed little bits of black material stuck to the inside of the dry recovery bottle. I don't know what it is, but suspect it could be hose material or maybe bits of O-ring. This bike is barely a year old, so I was reluctant to beleive the seals were bad.

thanks for listening,

At high altitude doesn't it take higher temps to make something boil? Just something I recall hearing as a boy.

I really wish we could get this figured out Mike... for the good of us all!

I think I would replace the cap anyway just to make sure it isn't weak...

It's the opposite. At high altitudes the boiling point of water drops. That's why recipes for baked goods always say "adjust for altitude". I'm going at it now like somethings broke. Gonna disassemble the thing, check it all out, and replace the cap. If it still boils, I'm gonna get me a KX500!

I wish you luck Mike...

Here's some info from buykawasaki from a KX500 / KX250 parts page:

49085-1059 CAP-ASSY-PRESSURE, P=1.6 (OPTION)

$24.09 at ronayers

STANDARD DISCLAIMER - I AM NOT saying it will fit a KDX.

It is for many late '80's through mid '90's KX's.

Any chance to route your overflow hose upward or replace it with a longer one that is routed up/looped up/then back down, etc.?

How slow are you going when it is boiling over?

Yesterday I was on about a 3 mile fairly steep, nearly constant climb over real rocky, loose terrain. Speed was around 8 mph. The altitude we started at was around 11,500', to get up to around 13,500'. I'll look into re-routing the tube, I took the right rad brace off to try and get more air flow. I might try mounting the recovery bottle away from the radiator. WRs have them under the rear number plate, XR-650s have them in front of the left engine case behind a guard. That cap you list is probably just the ticket though.

See if you can "borrow" your buddies KX500 cap.... that way you can 1. see if it fits and 2. if it does fit, see if it solves the issue. Without having to spend a dime!

3 miles at 8mph at that elevation sounds extreme for a cooling system.

I don't if it is possible or not to do on a 1995 and newer model, but the 1989 - 1994 KDX200's have a coolant overflow tank that is mounted under the left side panel.

Of interest is that according to the service manuals, the 1989 - 1994 KDX200's cooling system holds 1.4L, and the 1995 and newer KDX's have a 1.1L system.

Is there any chance to have a larger overflow tank so that it would have to expand more before it flowed out of it? Maybe taller, maybe larger capacity??

Keep in mind that there is the standard KX cap and the optional higher pressure cap.

Did you try the fancy coolant/addative stuff yet?