i have a 50 hp johnson runs fine replaced power pack, coils, waterpump,new prop <br />13 3/4-15 pitch, rebuilt carbs, new plugs .its on a 17 ft tri hull,no tach, on water hose it seems to have spark advance fine ,put on water starts fine runs good but when trying to get to full throttle sounds like i have full rpm but possible no spark advanced i adjusted timeing it was fine on hose .on the trip before last we got up on plane after a couple min. when loading boat back on trailer it seemed to bog down . last trip out all i could get was 7-9 mph trip befor 19-20 mph im wondering if spark advanced could be dirty or sticking which would cause it to work when it decideds it wants to any help will be greatful before i pull off flywheel
