does anyone know if there are performance parts available for the 3.5hp briggs motors-horizontal shaft? would like to have a camshaft. dont know if that is possible.
not that i am aware of. blueprinting the carb will help a lot, ditching the Governor, a better air cleaner and oh i dont care if it hurts it or makes it faster put a straight pipe on!!! if you want power get a 5 hp.
Another thing that will help a lot is to take a die grinder and round out the exhaust port. many briggs engines have a little hump inside the port to restrict airflow thus reducing power. just grind it out and make it smooth, Don't go too far with it but that will make a big difference after removing the governor.