My 2000 johnson 115 hp starts great and idles great but at half to wide open throttle I get a shutter or miss so bad that sometimes it wont even get the boat to plane out. Iv replaced plugs and primer ball and have new carb bowels coming cause they looked warped. Is there anything else I should look at? Any help would be appropriated thanks. Also note even with the new primer ball it would never get hard. Thanks again.