I picked up a second KLX300 for parts earlier this year and noticed that it happens to have near zero hours on it. The previous dingbat owner tried to launch it like a KX-F motoccrosser and didn't realize that it didn't have a rev limiter and floated the valves. The head was buggered pretty good but the bottom end is like new so I am going to build it up and give it to my niece. Now the problem is the head is obviously toast and has to be replaced. There are a few on EBay but they are not much cheaper than a new replacement. I searched the part numbers and no new replacement KLX300 specific heads can be found in Canada. However, there are lots of KLX250S heads available. They look similar on the parts diagrams aside from a reed valve on the side of the head on the 250S (which I assume is for emissions purposes) and share a similar part number (11002 for the 300, 11002/A for the 250). Anyone here that can provide some insight as to whether the 250S head can be used on a 300 lower end?