Home › Forum › Ask A Member › 1985 Evinrude 9.9 misfire › Re: 1985 Evinrude 9.9 misfire
Hi Don, you have it correct. It not firing correctly on the bottom cylinder, when i do my drop test it does drop off a little and idles back up when put back on. I just did another compression test and got 96 top and 95 bottom and did another spark test and it will jump a 3/4 gap. i have not had it on a boat yet but will this weekend. Im going to get another set of plugs today and see what happens. I cant readily see any droplets of water on the plug and i know the cylinder head is flat,new gasket "sierra" if that matters and torqued correctly. Im also going to get one of those inline neon testers. I have many of the 9.9-15’s and i know what they should sound like and thats what prompted the drop test. Before i replaced the pump,head gasket and thermostat i ran it for a short time and the miss was not there, so it has to be something i did or that water flow was established to somewhere that wasnt getting water before. Thank you very much! Dave