Check the Air Filter and make sure it is clean and clear.
Pull the plugs and see how each cylinder is running.
Check all the rubber fittings. You can spray them down with carb cleaner and see it the engine smooths out.
Check the filter in the fuel line and then clean the carbs.
If it is not the fuel system then I would go to the Coils, CDI and plug wires. (Go here first if no spark in a cylinder)
That would be my starting point.I am sure others will be along with other suggestions.
Air-Fuel-Spark that is about it.
Last edited by BillyIndiana; 09/18/2019 7:34 AM.
