Plastic Classic Forum

Input, thoughts, experiences...?

I've been looking around at what might be a good (or better) solution than what I have for powering an A-30 via outboard. I've used a 65# long shaft Merc 4stroke 6hp on my sub-6k displacement Ariel and that will push the boat fine until winds get into the 20's, and then she doesn't have the 'oomph' to go straight upwind ("tacking" works - point off a bit and you can make progress...). This means that in case of a storm I have to evacuate upriver extra early, and/or that coming into an inlet has to be carefully timed with tides/currents in mind.

So an A-30 is pushing 10k displacement when ready to cruise, and a bigger engine than the 6hp would be nice, all things being equal.
They never are, though, right...?
The Merc 8 or 9.9, next steps up in hp, weigh in (lightest) at 84#'s, probably 90#'s+ in a long shaft version. A 25-30% weight penalty, out on the end of the boat. Not good.

It's fairly common knowledge that several brands of older motors which at 9.5 or 9.9 hp are exactly the same motor as the 15hp from that maker, usually de-powered by use of a smaller carb or jets. (Not so with the Merc's any longer.)

So I've been checking out older 2 stroke motors, as they can be had fairly easily, when maintained are dependable, and are a good bit lighter than today's 4 strokes. Yes, they have drawbacks - louder, smokier, vibrate more, and not as efficient. But I am planning only to use the motor to get in and out of marinas/anchor, or in a pinch use it to push through tides and/or wind for a short while.

A short-shaft Johnson 9.5 from the 70's or 80's weighs in right at 60#'s, roughly the same weight as a 4 stroke 6hp. The 9.9's which followed them are a bit heavier, about 10#'s or in the low 70's range. And then you can swap the carb (for the bigger venturi) and exhaust (in the 15's it is tuned for back pressure to develop more hp), and you wind up having a 15hp motor for that weight.

As an aside/bonus, the 60's/70's Johnsons/'rudes were designed with a lowered powerhead & cowling for more casting space - they call them "turtle motors" because of how they look - and I'm wondering if this might allow them to fit a lazarette well better.

Anyone have experience with these motors in this application?

A local guy has a titled and running 9.9 along with (he was told) a non-running 15 that he is selling on Craigslist at a good price, and I'm considering buying these and selling the 6hp 4 stroke as a break-even proposition - except I'll have more hp at almost the same weight.

I was concerned about how you and all your boats fared during hurricane Flo but it seems you got thru OK.

I've used a 5hp long shaft 2-stroke that was in a fixed well on a Taipan 28 that I delivered from Venezuela to Brazil. When at sea I removed it from the lazarette to store in a cockpit locker.
My experience with outboard motors on boats ranging from my Triton to Alberg 30s is that 6hp is adequate if you're willing to work with wind and tide and sometimes pick your days for motoring when headwinds and waves that you don't want to tack against are not too strong. If you want to be able to buck stronger winds on a boat as big as the A30 then the 9.8 is enough to take care of most conditions.

More important to me than saving 10 or 20 lbs is to use an extra-long shaft and have the motor able to tilt up within an outboard well. With that you can motor more efficiently in far more difficult situations. Whether you go 2 or 4-stroke is personal preference. If you have to remove the motor from a non-tilting well or bracket then the lighter 2-stroke with no oil to worry about is a better choice. Otherwise, I'd rather not have a polluting 2-stroke.

I have an overview article of outboard wells in last months Good Old Boat ,magazine and will have a another article describing installing a 9.8 in an A30 in the next issue.

Kurt- take a serious look at the Yamaha's. I've pushed Tehani all over with an 8 HP, usually running at the "start" setting for hull speed.

Cruising the coast, Texas to Annapolis, Bahamas, and Pangas in Mexico, I saw Yamaha's maybe 3-4 to one over any other brand And they build their own engines.