Have Honda 15 with misfire problems when engine under heavy load. Worst with fine pitch prop. Dealer cannot notice misfire in test tank. Any else every notice similar problem. Have new carb, plugs clean,works fine.
Have had Honda 15 back to dealer twice, works fine in test tank. What specifically would dealer look for in ignition system, am told all is fine ......
Don't know what model you have but the some of the newer models have a rev limiter and may be hitting rev limiter. The newer models have an exciter coil, CDI unit, and ignition coil any of which could cause a misfire.
Engine is 2008 model. with standard 9 1/4 x 10 prop miss occurs at 4100 rpm, with 9 1/4 x 7 prop miss starts at 2700 rpm. So over reving does not seem to be a problem. In dealer test tank motor was reving up to 5000 rpm with no miss.
Miss most prevalent when 3 or more people or moose in boat.
That would very be hard to troubleshoot, may have to check timing and if each cylinder is firing at the point engine is missing. Not sure why the props would make that much difference.
Honda Misfire
Linear Mode
