Re: merc. 650
motormouth, if thats a three cyl 650, I just went through t-shooting and repairing the same issue. Mine is a 1973, switchbox (cdi) p/n-332-4796A3.<br /><br />Please describe how you are testing for sparks. If three cyl., motor must have harness connected to power head (or proper PH harness terminals jumped)and battery connected. Describe in detail.<br /><br />The folks here at Iboats were very helpfull to me, and, I used the search feature in this forum to look for answers. Suggest you do same. <br /><br />See this for example:
Merc 650 topic