Motorcycle Repair: 1979 xr 200 clunking noise, head gasket, xr 200

Question
well i have a honda 1979 or 1980 xr 200 i ve had it for three months i ride it every other day i replaced the head gasket a month ago but it burns oil. the guy i bought it from said he re bored it but i think he may have done a shotty job or not done it at all this bike also has a uni carb and super trap exaust i was riding yesterday i noticed a wierd clunking noise (other than that noise it runs great and has tons of power for a 200) i cant figure out what that noise or how to fix it and i dont want to ride it any more for fear of screwing it up plz help if you can

Answer
Well, you need to find out what's clunking.  I'm concerned it may be a piston or connecting rod knocking.  Take a long screwdriver and press the handle to your ear and the blade to various parts of the engine.  If you hear the noise loudest in the cylinder, it's a piston problem.  If the noise is loudest on the crankcase, it's a rod problem.  If it's loudest on the head, it's a cam or valve problem.

Regards
Rich