1979 mercury 70 hp 3 cyl. outboard issues

[rd9952]

My 70 hp mercury will start and idle up and down on muffs but in the water it boggs down and shuts off. We found the # 2 coil is either bad and/or the wire to be bad. Would it start and run with the # 2 cyl not working? And could that be the issue it is having trying to run in the water? Curiously also we can start and idle on muffs with the # 2 plug wire hooked up or not????? Does that make sense to anyone????

 

[racerone]

Outnoards run very well on a hose with 2 out of 3 cylinders working !--------That sort of testing means very little.----Do a compression test and check and see if spark will jump a gap of 7/16" or better on #2 cylinder.