Motorcycle Repair: 1986 Honda shadow 750, honda shadow 750, 750 honda

Question
why is my 750 Honda shadow V twin 1986 every once in awhile makes a loud backfire and is a little hard to start . It has 75,000km on it

Answer
Check the compression on both cylinders.If its above 100 lbs then check the valve lash. The valves as they seat in and run the clearance is lost.They may need to be adjusted. They are not seating good because they are to tight letting unburned fuel to build up in exhaust untill it reaches a level to burn and explode. It is also hard to start even if engine is warm, the valve stems grow with heat and get tighter.