When a motorcycle photo became a boat

[Cormanus]

Glad you sorted it, Lunchbag.

[peterbaron]

Good news it’s fixed.
Marine additional problem is water intrusion into electrics

[Cormanus]

Can be a problem on motorcycles too, although it generally isn't salt water which is particularly unforgiving.

[Lunchbag]

Well, thank you all for the encouragement.  Unfortunately, the result was not a great success after all.

We put the boat in the water and ran it four times over the weekend.  Regarding the key/ignition/kill switch:  It worked initially, then became intermittent.  Interestingly, this is a replacement switch assembly I installed only 3 years ago while troubleshooting another electrical problem (which turned out to be on the motor harness connector).

So, by Saturday I had lost all faith in this switch assembly.  I wondered whether I had kept the original switch assembly 3 years ago since it turned out to not be the culprit?  I found the original in the bottom of a box in the garage.  I did a bench test and it only passed in some switch positions but not all.  After applying contact cleaner liberally and twisting it back and forth repeatedly, it passed all checks.

An interesting note is that, when the contact cleaner dripped back out of this original switch, it came out perfectly clean.  Not dark brown like the fluid that came out of the 3-year old replacement switch which I had bought on Amazon for $50, and which I assume is rusted inside.

So I reinstalled the original switch and the switch-related issues are fixed.  It starts and runs.  However...the bad news is that we are getting worsening performance from the motor.  Not making the normal 5800 rpm, and decreasing each time we run it.  So we pulled the boat out of the water and I'll deal with it another day.

That will be another adventure for another forum.  The most important lesson of the weekend was that sometimes an OEM part is worth paying 4x the cost of the off-brand replacement.  The $50 part lasted only 3 years, whereas I believe the OEM part is original and served for 17 years, and is back in working condition now.

[peterbaron]

Exclusively for load-testing the wire, when both components connected to it are disconnected, I use a standard 15 W brake light bulb.