Powering an A-25 with a 2.2hp Mercury 2-cycle

[NickScheuer]

It worked wonderfully! The mishap outlined below with our transmission after running aground required us to move the boat about 600 yards from her marina slip to the local boat ramp with something other than her V-P MD17C. Our month-long slip rental ended yesterday. Ever present river current (toward the ramp) and the possibility of significant wind were concerns. A marina neighbor with a large 100hp pontoon boat had offered to tow up over to the ramp, but backed out three days prior to the deadline, afraid there was too little space between piers in the marina, along with a 20"-deep sand/mud bank right near his aft end (outward in the maneuvering space). Having used a friend's 2.2 Merc just the weekend before to power our 8' Eastport Pram for a dinghy even with our Power Squadron event, I figured it had sufficient thrust to drive our DuNORD, slowly, so I whapped together a bolt-on motor mount for our swim platform. In case the motor failed, or otherwise proved not equal to the task, I recruited my son and another PS friend for paddlers using the dinghy's 7' oars. Friday everything was in-place for the move, with only a light breeze, whereas the previous day had seen gusty 20mph+ winds.

So I fired up the little Merc, spun it around 180-degrees (no reverse gear, nor neutral) and it pulled the DuNORD right out of her slip as if we did this every day. Out in the space between piers I turned the motor around 180 again and powered ahead right out into the river, neatly avoiding the mud bank on our way out. I turned upstream (wrong way) just to determine whether the Merc would drive against the current. No problem, somewhat slow, but what can we expect from 2.2hp, eh? Circling back toward the ramp it was clear that my two crew were pretty much along for the ride until reaching the launch ramp pier where they passed lines to my waiting wife. Piloting the Albin while standing on the swim platform was easy, visibility was fine with the cockpit cover folded down.

I've always had some worry when cruising with a 43-yr-old diesel as our sole power, especially since I have little ability to diagnose and fix anything However, as this experience with a small outboard worked out so well, I'm sort of in the market for a used 3hp motor. I'd be partial to a Yamaha as the 9.9hp "Yammerhammer" we used 18 yrs in our 28' Shearwater Yawl never ever let us down. Nothing at all wrong with the Merc, ya'unner'stan.

[jerridsc]

So Nick, having just read about your 2.2 hp outboard outing, what do you think now of my plan to power my A25 with a 40 or 50 hp outboard? It has a gear ratio of 2.9/1 and can turn a 14 inch prop with a workboat pitch of 11?

[kerrye]

We keep a Tohatsu 9.8 on a drop down bracket It’s got us out of a couple of jams. It’s also nice for manoevering in tight quarters. I’m surprised more A25’s don’t keep a spare outboard handy. I think a 40 or 50 hp outboard on an A25 would be overkill but I’d probably use whatever was handy on Craigslist

[kerrye]

Let me add, I wouldn’t bother with a 2 or 3 hp. Get something big enough to power you at hull speed 8hp at least??

[NickScheuer]

Our boat came to us with a drop-down motor mount which I removed because it would have interfered with my swim platform design, which was not all that large to begin with. I would limit any auxiliary outboard to motors weighing not more than 40 lbs so that moving it from a "carrying mount" up at deck level, off to one side down to the "operating mount" on the swim platform would not be a heavy chore. With luck, the motor would never be used on a cruise. I prefer oars for our dinghy, even for fairly long pulls across a large anchorage.

A 50 hp motor would certainly work, although remote steering, throttle, and probably tilt need to be rigged. Less hp might be better as the A-25 can only go so fast and it doesn't take 50hp to go at hull speed. Hull trim is the big question. You don't want to have your boat permanently out of trim by the stern.

[Dieselram94]

I plan on buying a brand new tohatsu sailpro 6hp outboard as a backup. I believe it’s sufficient. I’m very capable of repairing my diesel for most problems, but I always like a plan B!

As far as a 50hp outboard goes, why? Is the diesel dead? It certainly will be less efficient then the diesel...

[kerrye]

I’ve got a 6hp and a 9.8hp. I’d go with a 2 cylinder for the smoothness and electric start. I think the extra long sail pro may not be necessary for the A25

[Dieselram94]

I’ve got a 6hp and a 9.8hp. I’d go with a 2 cylinder for the smoothness and electric start. I think the extra long sail pro may not be necessary for the A25

How long of shaft do you think is necessary? A regular long shaft? I haven’t had a chance to actually measure

[kerrye]

I haven’t measured it but I have a drop down bracket and there’s at least a foot of the motor in the water in the up position. I don’t know for sure if the 9.8 is a long shaft or a sail pro extra long. I strongly suspect a standard shaft motor would be adequate.

[WillieC]

How many words are two pictures worth?

Outboard on A25.jpg

IMG_1087.JPG

[Dieselram94]

I like that hard top! Seems quite a bit of weight hanging off the swim deck?

[Dieselram94]

I haven’t measured it but I have a drop down bracket and there’s at least a foot of the motor in the water in the up position. I don’t know for sure if the 9.8 is a long shaft or a sail pro extra long. I strongly suspect a standard shaft motor would be adequate.

That’s interesting? Do you have any pics?

[WillieC]

Dieselram, I only report wut I seen. This is not the WillieC. The owner was still "dialing it in". The extra weight on the transom can't be any worse than the 500 Ranger tugs we saw with the davit mounted dinghies dragging the lower tube in the water behind the boat.

We do, however, have a very similar BC hardtop. I wouldn't leave home without it.

[kerrye]

513D6537-DD57-442B-BADD-16A76C2F3CED.jpeg

Motor down. You can see a regular shaft motor should be adequate

[stmbtwle]

I agree that 2.5 hp is marginal. It would work fine around the marina or in calm weather, but out in the open with some adverse weather I don't think it would be effective. I'd probably want a 6, and live with the weight @60#, the same as a 4. Mercury does make a 3.5 that's about the same as the 2.5.

Amazon has several air-cooled motors that might get you in your weight range.

Otherwise you'll probably have to settle for a used 2-stroke.