ASK THE MXPERTS: MY KX450F OVERHEATS, WHAT’S THE PROBLEM?

On Jan 27, 2011 Last updated Mar 23, 2014

Dear MXA,
My son’s Kawasaki KX450F keeps overheating. We run Engine Ice and I can see the coolant circulating in the radiator. I don’t have the money to take it to a mechanic. Any help is greatly appreciated.

1.8 radiator cap.

1.6 radiator cap.

We talked to Pro Circuit’s test engineer, Zach White, and he said that cooling problems can only be cause by a head gasket leak, bad radiator cap, impeller issues or clogged hoses. He did recommended returning to a regular antifreeze solution. Zach also said that that the old black head gaskets were easy to spot a head gasket leak on, but that the new silicone clear gaskets can be leaking and you still couldn’t see it. He recommends borrowing another radiator cap for a day (since radiator caps have been known to fail). Pro Circuit runs a 1.6 radiators cap, but on many bikes MXA runs a 1.8 radiator cap (instead of the stock 1.1).