Merry Fisher 725 auxiliary outboard - any tips?

[norstar]

Hi all,

This isn't meant to be a thread for debating the merit of a backup outboard, but rather the approach to choosing and fitting one.

From what I can see on my MF725, the 150hp Yamaha is offset slightly on the rear transom. It *looks* like there's enough space alongside for a smaller outboard.

A user, Major Catastrophe posted on another thread that he's got the aux outboard linked to his main one so it steers with the wheel and that he's got an emergency fuel line hooked up so it can use the main tank.

I'm after some points so:

1) Can a small outboard use the main fuel supply? I thought it needed some oil added?
2) Has anyone else mounted a 2nd outboard on the transom of the MFisher?
3) How do you link the two to give steerage via the wheel, or is it a case of lash and dash with some rope?
4) I'm aiming for 10hp. Would this be best as a 2 or 4 stroke?
5) Any engine recommendations?

Thanks!

Richard

 

[neale]

1) Can a small outboard use the main fuel supply? I thought it needed some oil added?

Only needs oil if you choose a two stroke. Otherwise it can use the boat's main tank

2) Has anyone else mounted a 2nd outboard on the transom of the MFisher?

Not on a MF, but have tried various outboards on a SportsCruiser of a similar size

3) How do you link the two to give steerage via the wheel, or is it a case of lash and dash with some rope?

I didn't bother. Get a tiller extension for the aux and steer it from the cockpit

4) I'm aiming for 10hp. Would this be best as a 2 or 4 stroke?

Two stroke would be best cos it's lighter. Trouble is you will have to buy used as they stopped selling them in the EU in 2006. I would go for a Tohatsu 9.8 two stroke. Best power to weight you will find. Get long shaft as short shaft will be spinning the prop in air in choppy conditions.

5) Any engine recommendations?

See above

 

[Firefly625]

Hi all,

This isn't meant to be a thread for debating the merit of a backup outboard, but rather the approach to choosing and fitting one.

From what I can see on my MF725, the 150hp Yamaha is offset slightly on the rear transom. It *looks* like there's enough space alongside for a smaller outboard.

A user, Major Catastrophe posted on another thread that he's got the aux outboard linked to his main one so it steers with the wheel and that he's got an emergency fuel line hooked up so it can use the main tank.

I'm after some points so:

1) Can a small outboard use the main fuel supply? I thought it needed some oil added?
2) Has anyone else mounted a 2nd outboard on the transom of the MFisher?
3) How do you link the two to give steerage via the wheel, or is it a case of lash and dash with some rope?
4) I'm aiming for 10hp. Would this be best as a 2 or 4 stroke?
5) Any engine recommendations?

Thanks!

Richard

buy a 4 stroke and you can use main fuel supply, buy a 2 stroke outboard and you will save weight, but you will then need its own fuel supply as a 2 stroke engine uses a fuel/oil mix..

a 725 is a pretty light boat, a long shaft 6hp would push that along at 4 knots easy... a 10hp perhaps up to 6 knots... just depends where you use your boat, how far you go out from the coast...

a few years back I had a Merry Fisher 625 and had a 6hp suzuki 4 stroke as an auxiliary, it would move us at a good 5 knots, but never needed to use it in anger. I will try and find a picture of its bracket and post shortly..

 

[neale]

And don't expect a great deal out of an aux outboard. In flattish seas with average winds you might make 4 knots. With big waves and strong winds it will be next to useless. Might just be usable to get you out of trouble, but if you choose a two stroke you will have to have a separate fuel tank and that will limit how long you can run the aux for.

 

[norstar]

Fair weather cruiser

Thanks for the replies. I should have said about my "operating envelope"!

I previously berthed at Sparkes marina in the Solent and ventured out as far as the Nab Tower for fishing purposes. I'm moving to Gosport next week however.

The MF isn't too happy in very rough weather so although conditions can obviously change, I don't generally venture out in anything rough as it's no fun and I can't make any headway without slamming.

I'm just really after the assurance of having a backup option to get me back into harbour in a slight/moderate sea. If it's really rough then I accept I'm going to need help in all likelihood - and it'll be my fault for not having checked the weather properly!

Thanks Neale and Firefly - I'd be grateful to see pics of the setup if you can. The tiller option was in my mind as a fall back option, but when this other guy mentioned connecting it to the main outboard I thought "if that's easy enough, that would be great".

 

[Firefly625]

I would try a 6hp... others may shout me down, but you are not going that far out, if you have a problem in the solent there are always people around to help, you just need to be able to get out the way of anything big and be able to make some way.. but that is a decision you will need to make...

this is the installation on my 625, there was just not quite enough room to mount side by side so a outboard bracket was necessary.

 

[lionelz]

Thanks for the replies. I should have said about my "operating envelope"!

I previously berthed at Sparkes marina in the Solent and ventured out as far as the Nab Tower for fishing purposes. I'm moving to Gosport next week however.

".

Which marina in Gosport? are you putting it on a drystack?

 

[norstar]

Thanks for posting those pics.

It looks to me like my 725 has a slightly wider rear transom for the outboard, but not the higher bit to each side that your bracket is mounted in front of.

I've emailed Jeanneau to ask if it'll even take the weight but a bracket wouldn't be the end of the world for that matter.

I noticed that a few other boats of the same sort of size all had 6hp engines on similar rigs, so looks to be the preferred option. I'll look into it more...

 

[norstar]

Which marina in Gosport? are you putting it on a drystack?

Premier Marinas and no, we're in the water on a pontoon. They gave us a good deal in the end so I like sitting on the back of it with a cold ale, watching the world go by once I'm back in.

Doubt it would be as comfortable on top of the dry stack

 

[Firefly625]

Thanks for posting those pics.

It looks to me like my 725 has a slightly wider rear transom for the outboard, but not the higher bit to each side that your bracket is mounted in front of.

I've emailed Jeanneau to ask if it'll even take the weight but a bracket wouldn't be the end of the world for that matter.

I noticed that a few other boats of the same sort of size all had 6hp engines on similar rigs, so looks to be the preferred option. I'll look into it more...

I think some 725 have twin engine installations so I am sure it will be able to cope..

 

[Firefly625]

having odd issues trying to upload any photos today.... but shows bracket install, although you won't need one by the sounds of it.

 

[Fmicol]

hello,please could you explain us if it is easy to drive to the right direction with the small engine deproted on the side?

 

[LadyJ]

The 725 has a space on the transom for an aux and have seen a couple with a 6hp longshaft. I've a 755 with no space on the transom so went with same type of set up that Firefly has. For close quarter manovering you'll need to steer the aux but on longer running you can fix the aux in a straight line and actually steer with the main engine as a rudder.
As others have said, the reality is that in chop an aux will simply keep you off the rocks until help arrives but in calmer weather you'll get c. 4knots on a 6hp.
Personally I'd not link it to the main fuel tank as having a spare is no real hardship and also gives peace of mind for contaminated fuel in the main.
I did toy with not having an aux but in my head I wanted the comfort of it so understand your desire to do the same.

 

[Cbjroms]

Despite the OP's declared intention that this thread is about fitting and not deciding on an aux outboard, my experience may be of interest. I am based in Southampton water and have just moved from a small sailing boat with an outboard to a Merry Fisher 645. I, too, was going to fit an aux outboard to my MF645 until I spoke to a a couple of people with similar boats in Hythe Marina. Indeed one guy is an outboard mechanic and uses SeaStart instead of having an aux outboard - the cost is the same, an aux is not going to get you home in a reasonable time and you don't have to worry that it will not respond on that one occasion in its whole life that you really need it.