I hbought a 1989 maxum open bow 16 foot speed boat with a 75 horse mercury out board last year everthing ran good but this year the 3rd spark plug keeps fouling out and engine will bog down and then come back to full power I think its a coil problem but dose this engine have a magneto on it? I went to nappa and they said the 89 has 3 coils but Im counting 4 it has four cylinders and its a two stroke i set idle mixture screws to factory specs thinking it was to rich due to oil on the plug im lost can some one please help :facepalm:
