Re: 1981 40 hp merc 2cyl no spark
Once you are SURE the battery is fully charged and all cable connections are clean, bright and tight, if the motor still cranks below the minimum cranking speed for the ignition to operate, you can test the starter, grab your handy setr of battery jumper cables, attach one end to the battery and while a helper is cranking the motor with the key, attach the positive jumper cable directly to the positive post on the starter. If the starter speeds up you may have a poor starter relay, if no change then suspect the starter needs cleaning at least, possibly new brushes and/or a new armature.