Motorcycle Repair: LOSING A CYCLINDER, honda 450 nighthawk, plug caps

Question
I HAVE A 1985 HONDA 450 NIGHTHAWK. WHEN I RIDE IT FOR MORE THAN A HALF AN HOUR, IT GETS HOT AND ONLY FIRES ON ONE SIDE. AFTER IT COOLS DOWN A BIT THEN ITS OK AGAIN UNTIL IT GETS HOT AND IT DOES THE SAME THING AGAIN. DO YOU HAVE ANY SUGGESTIONS?             THANKS IN ADVANCE

Answer
Mike, being that it fires both plugs at once, it could be a bad plug or spark plug cap. You could have an air leak in the manifold, a partially blocked main jet in the carb, due to water or debris floating around in the bowls.
Check the plug caps for matching ohms readings, replace the spark plugs, check the float bowls by draining the carbs at the drain screws and catch what comes out. That may give you an indication of a further need to clean the carbs.
These carb should have anti-backfire diaphragms that could be giving problems, but they generally are pass-fail, as is the petcock diaphragm.
Be sure the valves are set correctly and that you have near matching compression on both sides.

Bill Silver