Outboards for ex-Inboards...?

[CapnK]

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.

[Lars]

James baldwin has an extensive article in this months good old boat regarding his work on outboard motor wells in older cca type boats. I am an engine hater by nature but for what it's worth I have had 4 tohatsu longshaft outboards and they are about as good a compromise as you can get. I can push my albin vega maxed at 6 knots but 5 at about 1/2 throtle is what it likes. Never been pushed around coming into inlets and i give it no thought even in some rough cuts in the bahamas. We did get caught out bound for nassau from northwest chanel and motored into 20 knots in the tounge if the ocean for abut 20 hours averaging  about 2 kts with wide open throtle "Not good". Another  good thing is the smaller outboard will double as your dinghy motor and of course fuel economy is great on the 4 strokes.

[CharlieJ]

Been eztremely pleased with both my Yamaha's. the 8 on Tehani. and the 4 on Necessity. usually run both a half throttle to get hull speed.

[Frank]

Outboards are so easy compared to inboards.
One diesel repair = one new outboard 😄

For your A 30, I'm thinking you'd want an 8hp long-shaft at minimum
Electric start is really nice.....remember Kurt....you're over 50 now 😄

[Godot]

Funny...I've come to love my diesel. I mean, when I don't hate it. Old Yanmar 2GM (just 2GM, not the 2GM20 and raw water cooled...no heat exchanger). It took awhile to become comfortable with it; but I'd hate to give it up. If nothing else, it is always underwater. On my Seafarer, I couldn't run the engine in heavier winds and bigger waves as the propeller would periodically leave the water. Not a good thing.

The Yanmar hasn't been terribly expensive to maintain so far. Fuel lines, impellers, filters...basic stuff. It's 36 years old so is beginning to smoke some at high RPMs. I don't like that and may rebuild the motor eventually.  I'm guessing parts would be around a grand, and labor would be free (me). I also need to replace the motor mounts, which are surprisingly pricey.

It doesn't use much fuel. Has an alternator (smaller than I'd like, and pretty basic...I'd like to upgrade to something smarter and bigger...that would be rather pricey).

If you want an outboard on the back (you know...outboard), I don't think 90 or 100 pounds is going to affect you too much. If you yank the diesel engine I think you'd probably be in a solid net gain situation. Close up the aperture, lose a bunch of weight, go faster.

That said, James Baldwin does seem to be the expert on outboard motor well conversions.

[Owly055]

Funny...I've come to love my diesel. I mean, when I don't hate it. Old Yanmar 2GM (just 2GM, not the 2GM20 and raw water cooled...no heat exchanger). It took awhile to become comfortable with it; but I'd hate to give it up. If nothing else, it is always underwater. On my Seafarer, I couldn't run the engine in heavier winds and bigger waves as the propeller would periodically leave the water. Not a good thing.

The Yanmar hasn't been terribly expensive to maintain so far. Fuel lines, impellers, filters...basic stuff. It's 36 years old so is beginning to smoke some at high RPMs. I don't like that and may rebuild the motor eventually.  I'm guessing parts would be around a grand, and labor would be free (me). I also need to replace the motor mounts, which are surprisingly pricey.

It doesn't use much fuel. Has an alternator (smaller than I'd like, and pretty basic...I'd like to upgrade to something smarter and bigger...that would be rather pricey).

If you want an outboard on the back (you know...outboard), I don't think 90 or 100 pounds is going to affect you too much. If you yank the diesel engine I think you'd probably be in a solid net gain situation. Close up the aperture, lose a bunch of weight, go faster.

That said, James Baldwin does seem to be the expert on outboard motor well conversions.

About $600 for everything for your 2GM including new valves, new piston and rings, all the gaskets, new injectors or tips.... I'm not sure which.... pretty cheap to work on the 2GM..... Here's a link.   http://shop.toadmarinesupply.com/ships_store/?p=multi&ident=308277&spnum=2GMREBUILD&name=2GM%20Common%20Rebuild%20List&image=yl.gif&multi=3   After spending over 4K just for parts on an Isuzu 4 cylinder diesel I rebuilt last winter......... looking to do another shortly, that looks cheap by comparison.  I'm into a Perkins 6 cylinder right now, and expect to be able to do it  with under $2k in parts..........  There is no after market for Isuzu parts for some reason.  I love the engines, but the costs are so  high!  Super efficient, and long life..... both of these exceeded 20,000 hours before rebuild, and I'm doing them because the owner is getting nervous about the hours and they are "mission critical".

                                       H.W.

                                                   H.W.

[Godot]

Well...not quite that cheap. Some of the part numbers on the list are not available anymore. They need to be substituted. Total price a little more than a grand...

Manf.	Part #	Product name	Price	Quantity	Total
Yanmar	121000-22091	Piston with rings	$101.87	2	$203.74
Yanmar	728270-92605	Gasket Set	$189.05	1	$189.05
Yanmar	24341-000260	O-Ring 1A S-26.0	$1.78	2	$3.56
Yanmar	728170-53100	Fuel Inject Valve Assembly	$149.55	2	$299.10
Yanmar	128270-01332	Cylinder Head Gasket	$70.47	1	$70.47
Yanmar	128275-11500	Injector Cover	$5.05	2	$10.10
Yanmar	128275-11490	INSULATOR	$8.36	2	$16.72
Yanmar	124950-11450	Chamber Gasket	$1.95	4	$7.80
Yanmar	124950-11410	Rear Chamber	$9.60	2	$19.20
Yanmar	105225-22400	Circlip	$1.95	4	$7.80
Yanmar	121000-11420	Front chamber	$55.80	2	$111.60
Yanmar	105225-22300	Piston Pin	$17.02	2	$34.04
Yanmar	105225-11110	Exhaust Valve	$10.96	2	$21.92
Yanmar	105225-11100	Inlet Valve	$11.75	2	$23.50
			Total		$1,018.60

Still, with a rebuild the motor should last for many more years.

[lance on cloud nine]

CapnK - what would you think about having a second 6 horse 4 stroke on an identical mount like you are currently using....for more push when needed, and as a complete spare in a pinch. It would also be already at a handy height to slide onto an awaiting dinghy. when the extra push is not needed, you could still get that almost magical, and hard to believe, modern 4 stroke - 1 banger fuel economy. just a thought.

[Captain Smollett]

8 HP Sailmaster (extra long shaft) on my Alberg 30, 1992 iirc, two stroke.

She's a sailboat first, eh?   :D  Outboard should be just to get into/out of dock!   ;D

Seriously, though: you should remember using that thing - when we could keep it running! - coming into Winyah Bay from outside.

I will say I LOVE LOVE LOVE that cavernous space where the inboard used to be.  But, I'm generally more willing to sail, even in light air, than many contemporary "sailors."  (Yes, we still see a lot of masted motor boats here....grrrrr).

[CharlieJ]

Me too,. BUT, cruising the ICW you had better have a reliable engine, or LOTS of time, particularly through east Texas and western Louisiana.

Once on cruising grounds, almost always sail in to anchor and back out

Glad to read you and boat fared ok

[Captain Smollett]

Me too,. BUT, cruising the ICW you had better have a reliable engine, or LOTS of time, particularly through east Texas and western Louisiana.

Yes, of course.  I often overstate my case to make a point.  Even here, ICW is not for engineless cruising unless you have unlimited time/ no schedule.  Even then, there are stretches that it'd be very tough.

We're lucky here in mid-coastal NC in that regard, as you know.  Good stretches of the ICW are routinely sailable. 

[CharlieJ]

for sure. Some of my favorite areas

[CharlieJ]

Been seeing the news about the flooding on the Waccamaw- Another favorite place. One of the very few fresh water anchorages on the entire ICW

[CapnK]

Will reply in/to specific posts later. Mostly I was wondering has anyone any experience with one of the "used-to-be-a-9hp/now-a-15hp" engines. :)

Because I would swap my 65# 6hp for a maybe 75# 15hp in a skinny minute, *and* the extra horsies would come in handy if I were to repower the A30. :D

Not having an inboard in 25' Katie makes her almost as large inside (after some reconfig) as is the 30' Sundance.

There are only 2 things I really prefer about the A30 over Katie, because other than these, it's a wash WRT everything else:
1) 9K displacement vs 5100#'s - makes a huge difference in "motion comfort", both underway and at anchor. (That's the only "better" thing all larger boats have over smaller boats, IMO.)
2) A30 is USCG Documented, and from what I understand, that is much more desirous to have for international travel.

[Craigie]

I repowered my Dufour 27 this summer with a used yanmar 12hp salt water cooled diesel. It all worked out well in the end, but it was a painfull process as the yanmar is very different to the old volvo that came out. Just pointing out that you should consider what you put in might not be as easy as a straight swop if you use a different brand.
In my case there were a few things to adapt: motor mount position = new brackets, shaft length = new shaft, shaft coupler, exhaust position and different hose ID, different prop direction = new prop,
All these add up and I think it would have been easier and cheaper to put a new outboard on the stern. It sure is nice to have the inboard though.
I looked at a number of outboard options and the most popular around the boatyard is the tohatsu 6hp 25" extra long shaft. Good value and light weight.
The 9.9hp motors are quite a bit heavier and difficult to handle. Not so much an issue if you are not going to be taking it on and off. As with all things boating it is always a compromise.

[Frank]

Swaps are like that aren't they.....
Even same brand swaps, if different (newer) years can cause modifications.
Seems never as simple as it appears..

Glad you're mobile again