Auxiliary outboard on SIB

[nicksharpe]

I'm thinking I'd be happier out at sea, especially with the kids on board, with an extra outboard, even though my 20hp Mercury never misses a beat.

So what's the options?

I'd like it to run off unleaded, so a 2 stroke is out. And I'd love to be able to mount it on the transom next to the main engine: the thought of all those spiky bits near the inflatable floor (and the kids) isn't great.

You'll see from the attached pic that the transom has a slight cutout where the engine is mounted. Could I pop a long shaft version on at the side of it on the raised section for emergencies only?

Just looking for ideas right now.

Thoughts?

[nicksharpe]

Sorry, pic: https://www.dropbox.com/s/ut20kff3zb...00007.jpg?dl=0

[charliee]

Maybe a pair of oars, an anchor and a hand held VHF radio would be a better option. Just keep the outboard serviced.

[nicksharpe]

Originally Posted by charliee

Maybe a pair of oars, an anchor and a hand held VHF radio would be a better option. Just keep the outboard serviced.

Ha. Got all those.

[Lee1]

I strap a 3.3 direct drive spare outboard across the bow of whatever sib I'm using if I'm going to remote bays with no moile or vhf service, I pack the outboard in an old tent carry bag, I store the outboard like this after severel other methods this works the best for me. . . . I lie the outboard over the front of my bow across both tubes eaqualy then I tie it down it in a figure of eight fashion between the front bow, and the port and starbord eye rings, (the front towing/lifting rings) I fill up the outboard when I use it and empty the fuel when I pack it back away I also Carry a small one litre fuel container in the boat storage bag, as my back up outboard and main outboard are both two stroke I can drain my main fuel tank if I had to, I've never had to use the back up yet but it is very reassuring its there if needed I've seen sibs with similar small 2/3hp outboards tied on the side tube grab ropes but tied across the front works best for me.

[HDAV]

Alternative to oars?
https://www.boatworld.co.uk/ron-mark...yABEgIkd_D_BwE

This is one of the lighter small OBs https://seamarknunn.com/acatalog/suz....html#SID=1478

Exactly how far out to sea are you going?

[Honeybadger]

I also carry a spare 4hp yamaha wrapped up in a tarp up front. If my main fails I slide it to one side and pop on my backup. Not enough room to steer so I lock the throttle open and steer with my oars. Gets me back to land in an emergency.

[spartacus]

Why don't you consider a 2-stroke auxilliary? Small engine 2-strokes such as Mariner 3.3hp and Tohatsu 3.5hp standard shaft would be perfect. They both have integral tanks so fuel and oil premix is dealt with. You can easily carry a spare 1 gallon tank and 2-stroke oil if you need to top up. Couple of advantages with 2-strokes at this size, with weight being a major consideration, plus with no wet sump they're a little more forgiving compared to their 4-stroke counterparts.

I take it the material flaps either side of the transom are more anti-splash that structural integrity. You could fit a fixed transom mount which the outboard can be permanently on. I'd also ratchet the outboard in the tilt up position while underway with a stainless steel u bolt on the inside transom near the deck. These small outboards succumb to vibration and the saddle isn't the most robust. My tuppence worth.

[Mikefule]

Another option, but expensive, is a Torqeedo electric. it breaks down into 3 parts: (1) the clamp/leg/motor/prop assembly (2) the tiller and (3) the battery. Each part is light and easy to stow separately.

My Torqeedo Travel will push my 310 SIB for an hour or so. Not fast, but a "get you home".

Following an unfortunate incident with my sailing dinghy, I can confirm that a Torqeedo will cope with complete inversion for a sustained period.

I bought brand new, but I have since seen them for sale second hand. I suspect a lot of them are bought as a primary motor and people are disappointed by the range, but as an auxiliary, they're good. Seamark Nunn are dealers.

They're also permitted on places like Rutland Water and other reservoirs where there are restrictions on petrol outboards.

[Andy JC]

Originally Posted by Mikefule

My Torqeedo Travel will push my 310 SIB for an hour or so. Not fast, but a "get you home".

I've considered one of these as a cheap/light alternative to an auxiliary on my SIB.
What amp hour battery did you have?
Would a small 7ah battery run one and for approximately how long?

[chipko]

Generally enough room on most larger sibs for a small auxiliary motor. Probably won’t even need a long shaft even when mounted on the higher transom sides. You might have to modify (cut) the splash flaps on your boat.
Also agree with your thoughts on 4 stroke to match main engine for ease of fuelling.
For longer coastal jaunts we would take our tiny Honda 2.3 along, stored on deck in a full padded carry bag, only to be deployed if required. Could also be transom mounted if preferred.
I think the lightest 4-strokes are the little Suzuki 2.5 & Honda 2.3 both around 13kg.

[nicksharpe]

Hugely helpful, thanks all, particularly chipko for the pictures which perfectly illustrate my set up.

I'm thinking the transom flaps could be removed temporarily then chocked back with either velcro or poppers.

[simonafloat]

I've now got a little johnson 2 stroke for emergencies. It lives wrapped in some tarp under my feet in the aerotec. My aerotec has the less common long shaft transom which is flat all the qay across. If I need to use it the mariner outboard has to be shuffled along a bit before I attach the johnson. The johnson has no integral tank but I made up a hose and primer bulb for it to run off the 25l mariner tank.

[Mikefule]

Originally Posted by Andy JC

I've considered one of these as a cheap/light alternative to an auxiliary on my SIB.
What amp hour battery did you have?
Would a small 7ah battery run one and for approximately how long?

Torqeedo is a specific make and has an integral battery pack. It is not a cheap alternative. They are designed as auxiliary power for yachts and that sort of thing.

https://www.electricoutboards.eu/tra...iABEgLfS_D_BwE

You are probably thinking of one of those trolling motors that runs off a car battery.

[Andy JC]

Originally Posted by Mikefule

Torqeedo is a specific make and has an integral battery pack. It is not a cheap alternative. They are designed as auxiliary power for yachts and that sort of thing.

https://www.electricoutboards.eu/tra...iABEgLfS_D_BwE

You are probably thinking of one of those trolling motors that runs off a car battery.

Ah, you are indeed correct Mike. And no, those definitely are not a cheap option!

[nicksharpe]

Originally Posted by chipko

Generally enough room on most larger sibs for a small auxiliary motor. Probably won’t even need a long shaft even when mounted on the higher transom sides. You might have to modify (cut) the splash flaps on your boat.
Also agree with your thoughts on 4 stroke to match main engine for ease of fuelling.
For longer coastal jaunts we would take our tiny Honda 2.3 along, stored on deck in a full padded carry bag, only to be deployed if required. Could also be transom mounted if preferred.
I think the lightest 4-strokes are the little Suzuki 2.5 & Honda 2.3 both around 13kg.

Attachment 122169
Attachment 122170

Hey Chipko. Looking back at this now (after buying a 3.3 2 stroke) I was just wondering what your max transom weight was on that boat, vs the weight you have on it?

I'm about 5kg over my 60kg max with the 20 and the 3.3 on, but consensus on here is that's no major issue.

[chipko]

Hi Nick,
Transom rated at 55kg, so at least 2kg over with the 13kg aux and 44kg main.
Usually carried the little auxiliary on deck in a padded carry bag, only to be deployed if required, so not concerned with additional weight when hooning around on the main. As only going at displacement speed on the auxiliary not too worried about exceeding the max weight stressing the transom.

[nicksharpe]

Originally Posted by chipko

Hi Nick,
Transom rated at 55kg, so at least 2kg over with the 13kg aux and 44kg main.
Usually carried the little auxiliary on deck in a padded carry bag, only to be deployed if required, so not concerned with additional weight when hooning around on the main. As only going at displacement speed on the auxiliary not too worried about exceeding the max weight stressing the transom.

Cheers, that echoes what everyone else is saying. Ailsa Craig this spring... Hopefully don't need to use the aux to get back from there!
N

[Lee1]

I would go with a slim 2 stroke and a direct drive one for ultra light weight around 13kg