Motorcycle Repair: 200xr valvea, air fuel mixture, full throtle

Question
I have a 1984 Honda 200xr, its been suggested that the valves need to be adjusted. Because recently it has started to burn oil, and bog out under load and full throtle.  Would a adjustment cure this problem.

Answer
Hi Dylan,

Valves:

Keeping valve clearances within spec is important. Regular maintenance should be performed. Tight valve clearances will eventually cause dishing/cupping of valves, valve seat damage, and poor performance. Loose valve clearances will cause noise and poor performace.

I suspect the cause of your performance problem is related to a excessively rich air-fuel mixture in the carburetor. I further suspect the air filter is restricted causing the rich condition, otherwise, carb needs cleaned and tuned to restore proper performance.

Burning oil:

The smoke seen is likely a result of the rich carburetion. Dark colored smoke for fuel related problems, light colored smoke for oil related problems.

Some oil consuption (burning) is considered normal as the engine wears. Excessive wear causes poor performance and excessive smoke from exhaust. To check condition of engine, perform a cylinder compression test and a leak-down test. Compare readings with those of factory service manual.

Respectfully,
Mark Shively