I have an amazing KLX351 which has developed a strange cooling and now starting issue.

I initially noticed the engine temp going up with my TrailTech tto. Eventually the red dashboard light came on and my engine temp climbed higher and higher. Naturally I was concerned and nursed the bike back home, using frequent stops.

The rear coolant reservoir seemed ok. Once it cooled down I checked the tank coolant level and sure enough it was down. I refilled and a few days later went for a good 3-4 hour ride. Normal temps. During the next day's ride the overheating issue came back.

This pattern continued for a few rides then the bike began having starting issues (where there were none prior).

I wondered if coolant was leaking into the motor. On oil change, I couldn't detect any signs of coolant (watery like or milky) in the oil. I use Engine Ice for coolant. Does it go less milky than other coolants? The plug looked good.

Any thoughts?

Is there a slow leak through the water/oil pump seal, that I can't detect? Internal head or base gasket leak? I do notice an initial puff of white-like smoke on initial starting (when I do finally get it started), that goes away once it gets going.

Thanks!

 

Did you lose more coolant after the good 3-4 hour ride and others after that? If so and it's not in the oil, it could be getting into the cylinder and out the exhaust pipe. Does the white puff smell sweet? Could be a head gasket or cracked cylinder sleeve.

 

Coolant loss seems consistent and is not much. Not sure about the sweet smell - haven't noticed. Would a cracked cylinder sleeve have other symptoms?

 

I'm not sure of other symptoms. You may want to give Bill a call and discuss it with him.

 

I'm thinking along these lines with IDRIDR. Any type/brand of coolant in the oil will show up quite dramatically. A small failure in a head gasket can let water seep into the combustion chamber and slowly draw out of the cooling system. That white puff of smoke is troubling, but as stated, you can usually smell a tell-tale whiff of sweetness that you can identify as coolant.

 

....and if you're not seeing it in the oil, it's probably not the water pump seal...

 

If the head gasket has failed and is letting coolant into the cylinder, you should be able to see bubbles (combustion gasses) in the radiator while the bike is running.

 

Thanks for your help guys! I will start with the head gasket thing as that seems like the most likely. Cheers!

 

Make sure the water pump hoses are not reversed. I am surprised high temp idiot light did not light, because I was an idiot to reverse them. Don't be a snappster.