Coolant overflow during break in

Just rebuilt my KTM 2 stroke, and when i put the coolant in i decided to use just distilled water so i could flush out the system before putting in regular coolant. Well after starting it up for the first time i decided to go on a short ride around the neighborhood and thought there wouldnt be a problem. When i came back from riding about 2 miles, i noticed water on my bike and thought it was a leak.

I should have known before i rode it, but the radiator did overflow a little. I did not let the bike stand still running at all. Is this normal for it to overflow that fast and could it have done anything to the new engine at all?

Sometimes rads have to seek their own level after filling and might burp out a little extra...or maybe you plugged something up while rebuilding and need to go in and unplug it.

If the rads were filled to the rims it's just burping down to regular level.

If you completely filled the system, it's going to spit out a little breathing room for itself.

Normal level, cool should be .5-1.5" below the cap seat.

Drain it, then measure how much you've put in. If you filled it to the brim and there was no air in the system, then it's as stated above; the water expanded when it got hot and had to go somewhere.

But, if you under filled it (it was filled to the brim but had a lot of air trapped in the system), you could make the motor run hot and boil over. The other problem could be you have a head gasket that's leaking.

So how was the level like after the bike cooled down?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now