KLX300R seized engine/possible engine swap

[bhcolvin]

I have a 1999 KLX300R which I bought this past April (2017). I only ever ride it on the weekends for no more than an hour (time constraints). Since I bough it, it has always ran hot. The oversized aftermarket pipe it has constantly heats and burns my leg, just from those hour rides. I've dropped it twice and both times the coolant boiled afterward, but it doesn't boil when I just riding it normally. Just this past weekend (late July), I went riding with some friends and put some hard hours on it. As I was coming in for a break I pulled in the clutch and the engine immediately stopped and locked up. I got off and tried to kick it over but it wouldn't budge. I let it cool down then rolled it back and forth in 6th gear to free it up. It starts and runs smoothly now, but there sounds and feels like there is something rattling around in the top of the cylinder.

 

What should I do? Can and should I try to swap another engine into it? What could the problem be? broken piston ring? broken valve/shim?

[brewster]

Best way to see the problem, is to remove the head.  Otherwise, it's just speculation.

Ride on

Brewster

 

[Hogfan15]

You probably dropped a valve. Don't run it anymore or you will have head damage that is expensive to fix.  engine swaps are possible but I think it's a shot in the dark. I haven't read of anyone doing it.  I may be interested in parts if you decide not to repair it. Good luck!

[bhcolvin]

10 minutes ago, Hogfan15 said:

You probably dropped a valve. Don't run it anymore or you will have head damage that is expensive to fix.  engine swaps are possible but I think it's a shot in the dark. I haven't read of anyone doing it.  I may be interested in parts if you decide not to repair it. Good luck!

Hogfan15,

I don't think its a dropped valve, it runs and idles smoothly. If I dropped a valve wouldn't it run terribly (if at all) and have a loss of compression? It could be a cracked or broken valve/shim, but I wont know until I take it apart. I definitely wont be running it anytime soon.  

[Hogfan15]

Like Brewster said you will have to pull the valve cover, and the cam girdle to get far enough to be able to tell if anything is broken or missing 

[honduki]

regarding swapping the engine out

i have seen a klx with  an xr 200 motor, so a crf230 could be possible also

[Hogfan15]

Thanks I appreciate it. I may have found a guy to repair my head so I may be staying with the Klx