I have an early 90's Mercury 50hp 3 cylinder 2 stroke that is giving me fits. It's always been a bit hard starting but now something is off enough that I need to hook up one of those portable jump starter packs to get it started.
For example yesterday after a few cranks I get her running and cruise around for a few minutes. Stop several times and restart with no issues. No jump pack used yet. Back at the ramp I turn it off. Now it will not start but cranks like hell. Hook up the jump pack and she fires right over. Does this several times and this is consistent with what it's been doing the last year or so.
Battery tested good and cranks starter fast. Electrical connections are all tight and clear of corrosion. I'm thinking electrical part(s) have failed but I'm tired of guessing. Have replaced a good number of things over the last couple years.
I did notice the voltage on my fish finder read 16.4 at times the last couple days. I don't recall ever seeing it near that high in the past. From what I've read regulator and/or rectifier are likely shot. But if so how would either of these cause the motor to only start on a jump pack?
Has anybody ever seen something like this before?