KDXRIDER.NET

I've had my KDX for three years or so, and in all that time I've never heard it doing the bubble bubble noise until the last two rides.

The coolant in the overflow tank has been there for three years until the second last ride I went on, when I noticed that it was all gone and the bike was making a bubbling noise.

There was no noticeable drop in performance.

I then changed all the coolant hoses (fitted some blingy green ones) and refilled it with coolant, including the overflow bottle, and yes I bled the system as well.

Next ride (which was the last ride I went on) I noticed again it was doing its bubbling noise and the overflow is empty.

No idea how much is left in the radiators or the rest of the system.

I've also recently fitted the aftermarket Pro Circuit pipe but I've ridden it since putting the pipe on without it boiling.

Is this normal occasionally for the bike to boil or overheat?

Could it be the sign of something else wrong? Do bikes start to boil when they are due for a top end rebuild for some reason? Is it possibly just because I'm riding it harder and it's nothing to worry about? Could I play with the jets and get it to run cooler now that I have the pipe on it (now making it a full Pro Circuit exhaust including silencer)?

It's summer down here but it hasn't been super hot when I've been out the last two times.

water pump messed up? might be the bearing?

Question: Have you looked at your transmission oil in these last couple rides?

You may want to drain your oil and take a look, possibly you've lost a seal, or the impeller has spun on the shaft in the water pump. I've taken my '01 220 on 6 hour loops in S. Florida (95F+ temp and 100% humidity) and never had an issue with overheating or boiling. Always been one of the nice things about the KDX,the 2 huge radiators and no bypass, keeps that engine nice and cool.

I changed the tranny oil between those two rides. Will drop it and have a look though, I tweaked my knee on the last ride and I haven't even washed the bike yet :( but I'm going to do it this weekend.

Am I looking for a milky appearance a la blown head gasket in a car or just separate water in with the oil?

It'll look like gray milk if the seal has gone, easy to spot just like on a car. If it's normal then you'll want to start looking at water pump.

Thanks.

Could be a head or base gasket issue letting compression into the coolant system. With the radiator full start the bike and remove the cap. If there is bubbles in the coolant then there could be an issue. The pressure could be blowing the coolant out adding to the overheating problem.

bad rad cap?

No milky gearbox oil, impeller tight on water pump shaft, bled cooling system again. Some slight bubbles coming up through radiator.

Going to try it out in the bush again but if it's head gasket its not losing any power.

Might be time for a top end rebuild anyway and see if it's still playing up after that.

How would I know if it was the radiator cap?

For the price of a radiator cap I'd just replace it. Could it be original?

I'd definitely try a cap first. I've seen people chase these problems all over creation, when in the end it was just the cap.