TOPIC: Most bulletproof outboard around 90hp

Gents I’ll wake up for forum a bit asking for experience and advice on older engines. My boat is rated to 125 but I was thinking of somewhere in the 75-90 range for fuel economy and because 125 on a 15 foot boat is madness IMO!

I have really been looking at 1980’s vintage 4 and 6 banger mercs and even some really clean mariners. They seem to have the best used parts availability and I hear they are very reliable.

In my experience reliability is usually directly correlated to how reliably one did PM and inspection. So assuming that a guy was reasonable at keeping up on his gear. Not FAA or NASA religious but well above average. What motor would you be bolting on if you knew you were going offshore and it was critical.

I need something that will-
Do good in saltwater
Be extremely reliable
Easy(relatively) to maintain
Easy to fix
Light weight is a bonus
Reasonably fuel efficient a double bonus.

Why not a new motor you ask? Because I have all my money tied up into building this boat and I can’t afford a new motor. Also I don’t like the newer 4 strokes. I like the rumble, and smell of 2 strokes. I had an ETec and I loved the ever living heck out of it. But they are just outside the budget right now. Maybe in the future.

Start slinging your thoughts!

Keep Chargin’
Andre

Hard to fault a 90hp or 88-Special JohnRude V4. They're good runners and shouldn't be terrible with fuel. Pretty reliable too. I'd say more durable than a Merc if used exclusively in salt.

A 90hp Merc Inline Six with small ports would be fairly economical, very torquey at lower speeds, and probably a bit lighter than the V4. The small-port Inlines have excellent idling quality.

IIRC, '79 thru '83 had the small-port configuration. Also IIRC, starting with the '84 models, Merc HP figures were taken at the prop vs. at the crankshaft. Thus a formerly 115hp became the new "90". And that 115 block didn't have the smaller ports of the previous years. So it wouldn't be inherently more economical than the small-port 90's.

I'll let Doc Frankenmerc confirm or deny those, his nogging is full of much fresher info than mine!

The Merc 75hp and 90hp Big Three's have an idle note reminiscent of an old Inline Six, albeit a bit rougher. They don't seem to have the internal issues that their Big Brother 4-cylinder had.

A good boating friend of mine picked up a blown 90HP Merc Triple and rebuilt it for his 16' ski boat. It had lots of pep and good torque out of the hole. As I recall it was pretty economical. Mechanically it'd be a lot simpler than a Johnrude V4. He'd run an older Merc 100hp-Six on that boat before, and the 90 was pretty much its equal in performance.

Anyway, just a few thoughts. I'm sure others will fill in. G'luck with your outboard search.............ed