'89 OMC Cobra 5.0 Litre (Ford 302) starting issue

[CoachRobJ]

I have a new to me 89 Reinell 215 C with the OMC Cobra 5.0. Everything about seems to be in great shape. I checked all of the fluids and inspected everything on the engine and it all appears good. I launched into the water today, I turned the key and let it idle for about 5 minutes (ran smoothly) then I lowered the idle to shift into reverse and it stalled. I turned the key to the off position and tried to start it again, but it was dead at the key. I tried turning the key several times and got nothing (no clicking, no turning, no smell of gas, just nothing). I got home about 30 minutes later and I turn the key and the engine turns but doesn't start. I turn the key off and try to restart it, but the key is dead again (nothing - no clicking or turning). The battery is fully charged with clean terminals and cables. The connection to the starter appears good as well. Thoughts?

 

[Scott Danforth]

start at the battery, clean the battery to cable connection to shiny metal and then re-connect, making sure the connection is tight.....now do that with every connection from the battery to the motor all the way to the key. that includes all the grounds.

when you are done, seal all the connections with marine electrical varnish

 

[CoachRobJ]

I will give that a try when I get home this evening. I know the connections are good on the battery because I cleaned those myself, but I will check the connection on the starter and ground connection.