My motor is missing at idle and low end up to about 2000 RPM. From what I have notice is that it does not occur all the time. Seems if I put the boat in and start it will run just fine. Then I will run down the lake and stop, then it will start missing. If the motor runs for a while the miss will sometimes go away. I have a couple of ideas what it could be but am not sure. I have pulled the plugs and gauged them and can not determine if it is one cylinder or not. What do you think it is.

you have to find out if it is fuel or spark, when was the last time you cleaned the vst tank and chek the lift end of the fuel pump to see if it has small crystals of old fuel , also ck to see if one of the injectors is getting junk to the injector thru the fuel distrabution hub, that where the hoses go back from injectors, if you cant do these things get a merc mech. also put a fuel pressure guage on the vst tank and run boat and see if pressure fall off, that will tell you if pump is clogged or going bad. either way clean the vst tank.

I am 95% sure it is a spark issue. It doesn't miss above 1800-2000 rpm. Plus I can smell raw fuel if the wind is at my back. I believe it is a coil pack. I am going to try and determine which one by using a timing light. If that doesn't work I will be of to a mech.