BCCHI, is right on. A Bowman ring will not cure a miss in any engine. The first things to check are #1 The Sparkplug brand, gap & condition.#2 The Sparkplug boot...make sure it is on plug all the way...and good condition...including the boot inside for cracks.#3 Make sure all low voltage connections are good on the ignition system.#4 Make sure the ignition battery is fully charged and capable of several min of good output.#5 Make sure the carburetor mixtures is set right...engine needs to be warm first.#6 Make sure all fuel lines are tight & not letting air to be sucked in.#7 If carb does not seem to adjust good...try a different one of about the same size.#8 Make sure there is no way air can leak into any joint between carb & engine.#9 Make sure carb pulse track is not blocked at all by CARB GASKET.#10 You may need to check reed valves to see if they are in good condition & seat good. ......... OK... that should give anyone a few items to check....Best Regards & good luck ! Capt,n