Motorcycle Repair: 84 yamaha virago 700, vacuum leak, rubber seals

Question
it started over heating then popping now it just backfires and wont run.got good spark.fully charged battery.fuel.please help if you can.

Answer
Sudden overheating and popping is usually the result of the motor running lean. This can be caused by a vacuum leak on the intake runner and/or a leak at the exhaust header. Check the rubber seals from the carb to the cylinder head to see if they are cracked. Check for sooty black deposits at the junction where the exhaust pipe bolts to the cylinder head.

If you have recently changed the air filter to a low restriction type or have installed low restriction mufflers, this will also cause the motor to run lean and hot - in both cases the carb will need to be rejetted and tuned to match the new components.