XR400 Burning Oil

[tuckmt]

My '96 XR400 is burning oil (approximately 8 oz after 20 hours of riding).

I imagine that this is not normal.

A couple of observations:
The spark plug has an burnt oily residue.
Just changed the oil and went to Honda 20W50 (mostly riding in hot south).

I have the Honda Service manual but it really just tells how to tear it appart and put it back together.

Some troubleshooting would help me here: valves? rings? etc.

What should I do next?

Thanks in Advance:cool:

 

[BigBore]

First off, try a compression test. Most likely, you've just got a worn out top end. Yes, it is possible that oil can get into the combustion chamber by getting past the valve stems, but I would start by checking the condition of your piston rings.

 

[tuckmt]

Any idea what compression I should expect on XR400?