Dave,
I've had a lot of bad luck with outboards. Cooked bottom cylinder, blown powerpacks and on and on. Literally thousands of dollars later, I can admit now that my folly was in hiring a shadetree mechanic. We've since parted company.
Like you, I tried to do a lot of work myself- most all of that work was successful, but it was simple stuff that any idiot could do with the right tools.
I've replaced every electrical component in my Johnson 40, according to Maxrules, SELOC and whatever other resources are out there. Just disgusted thinking about it so I'm going to quit now.
The worst part is the general shit-nature of a ruined trip. Women, buddies, fish- whatever. And the whole time knowing that you've just been screwed out of money, and that you really tried to give everybody a good trip.
Rant over.
I'm going to buy a new motor with a warranty. There are a lot of guys who get decades of good service out of an older motor. Just didn't work out like that for me x 10. What pisses me off so bad is that this Johnson is 20 years old, but less than 100 hours! I'm the second owner, knew the first owner as a Grandad, and he was an engineer so followed everything to the letter. I now use the piston as an ashtray.
Getting sick again. Better luck with whatever you decide.
Damn.