Fitting Auxillary Engine

roywebster · 20 June 2004, 17:27

Please can anybody offer advice on fitting an auxillary engine to my Humber 6.3 Extreme

Sue at Humber has advised me that the transom will take the engine but has warned me that she knows of several incidents of auxillary brackets breaking because of the pounding that Ribs take at sea.

Roy Webster

Turbodiesel · 20 June 2004, 17:56

Put a sacrificial plate on the transom so it wont damage the transom, and then have the engine in the boat rather than hanging over the back. (if you have the room). You can then put an eye bolt or somthing simular in the deck to tie the leg of your spare engine down.

Brambles · 20 June 2004, 19:06

This is how Scorpion do it on an 8.1m with an outboard. The bracket is bolted directly to the transom. The auxiliary engine is stored in the transom locker and will be hoisted into place via the A frame if needed. The long shaft Suzuki does take up a lot of room in the locker but we think there is less chance of damage with this arrangement.

If you have room I would recommend this approach. Hope this helps?

Alex Brown · 20 June 2004, 19:34

Hello Roy,

Yeap, I had the same from Humber (Andrew in this case) when I got my Destroyer from them a year and a half ago. Initially I had ordered a stainless bracket, but with some modification on the transom, it now takes my long shaft 4hp 4-stroke Suzuki engine properly, and it's bolted through the transom too, which in theory makes it stronger.
I keep the aux engine lifted whilst travelling along, and when looking back in choppy conditions, the thing shows no sign of being thrashed around too much.
Look here for rough pic:-
http://gallery.ribseadrive.co.uk/lif..._0322_154600AA
and
http://gallery.ribseadrive.co.uk/pem..._0830_103201AA

-Alex

roywebster · 21 June 2004, 00:20

Alex

Thank you for your advice this looks the best option as there is not a lot of deckspace for an engine.

Roy

DGR · 21 June 2004, 11:12

Alex,

From the pics I can't see wether its bolted onto some sort of bracket - or just straight through the transom. I like the idea of setting mine up like yours (i.e. always there), but am wary of brackets and their ability to break unexpectedly!! I'm also wary of my ability to drop things, especially an engine whilst trying to get it onto aforementioned bracket....while at sea....when I REALLY need it......

Dylan...

gingercoastie · 21 June 2004, 23:02

Just bought an aux engine last Friday and have put it staight on the transom.

I figured that when I am most likely to need the aux engine is just about the time you least want to be hanging off the back end of the boat trying to fit an outboard.

I also made sure that I had an additional source of fuel, just in case the problem was with the main tank. I got the 6hp Suzuki (heard somewhere 1hp for every meter) and it has a biult in 1.5 ltr tank and I got a 22litre plastic tank as well.

brucehawsker · 22 June 2004, 06:35

Just to say have been running the Suzuki 6hp on my SIB since March and it is a brilliant piece of kit. No problems at all, sweet runner. Will be using it as the aux on my 6.5M Solent is due course.

Quote:

Originally Posted by gingercoastie

Just bought an aux engine last Friday and have put it staight on the transom.

I figured that when I am most likely to need the aux engine is just about the time you least want to be hanging off the back end of the boat trying to fit an outboard.

I also made sure that I had an additional source of fuel, just in case the problem was with the main tank. I got the 6hp Suzuki (heard somewhere 1hp for every meter) and it has a biult in 1.5 ltr tank and I got a 22litre plastic tank as well.

mark hannaford · 22 June 2004, 16:03

i am going through the same problems at present with my boat, which is fitted with 140 suzuki.
i have been told by ribcraft that i can bolt the 4hp straight onto the transom
with a bracket. i want to the use the engine as a tender propulsion as well as a backup .the longshaft would not be suitable for a tender but equally the standard shaft would not be so efficient without an engine bracket due to the propeller being near the surface of the water!

DGR · 22 June 2004, 16:45

I was thinking the same thing - use it both as an aux and for a tender. However, the long/short shaft requirement does rather make each suited for a different purpose. Also, for my Ribcraft I'll need an 8HP (using the 1HP per metre rule that seems popular) - and it needs to be quite a big tender to cope with that.

Therefore, I've decided that I'll get the aux for the rib, and some paddles when I get the tender, and face the fact that I will have to do some exercise. Having said that, rowing in to the shore has got to beat swimming in, which is always the other option!!

D...

Alex Brown · 22 June 2004, 20:03

Quote:

Originally Posted by DGR

From the pics I can't see wether its bolted onto some sort of bracket - or just straight through the transom.

Just like Gingercoastie, my aux engine is attached directly to the transom - no bracket at all. It's permanently fixed, like the main engine and is locked on to satisfy the insurance man.

If I ever need to use it, it usually takes 1 pull and it starts - I generally run it for at least a couple of minutes before every trip.

-Alex

codprawn · 22 June 2004, 20:14

This may sound totally daft BUT - just one aux looks so unbalanced - would 2 8hp fourstrokes give better economy for slow river pottering etc than the main engine?

Even stranger would the 2 little fourstrokes add anything to the top speed or would you lose more than you would gain?

IE a 3 engine boat!

Alex Brown · 22 June 2004, 20:20

I am not sure - I think it would look more odd having 2 aux engines on the back to be honest!!

My 4hp gets me along at around 4.5knots, which is all I expect, and all I'm after - at the end of the day it's there to get me out of trouble, it may not be fast, but it does the job.

However, sometimes, the 4hp engine is used to handle the boat in confined spaces (there isn't a 180 degree lock on the main engine), but when trolling around with the 140 4-stroke, it probably uses less fuel than the 4hp going flat out.

-Alex

Tim M · 23 June 2004, 09:50

How do you guys keep your engine out of the water when they're bolted on; can you rely on the catch on the engine or do you use a piece of wood or something.

I am considering getting a aux. for my 4.1m RIB (had an Evinrude brake down on me so now I'm paranoid!). I was thinking a 2.2. Any thoughts as to whether this might be enough?

Alex Brown · 23 June 2004, 12:49

Tim,

My aux engine rests quite happily on its engine latch - http://gallery.ribseadrive.co.uk/cru...8_142820AA_001

The engine lock also stops the engine from being bounced up, so when the boat is bouncing along, the engine stays pretty rigid and doesn't get thrashed around at all.

I guess every setup is probably different - this way works great for me, but may not be so solid with others. As you can see, at speed, the bottom of the engine is completely out of the water which is just as I'd want it.

-Alex

swginn · 23 June 2004, 14:44

Mine is attached directly to the transom just like gingercoastie's and alex's. It is a long shaft but sits well clear od the water. Its own tilt lock keeps it very rigid and no bouncing occurs at all. One handy thing is that the engine has adjustable steering friction which can be locked so that it doesn't turn in towards the main engine/ A-frame. This setup is very solid and works well for me. The engine was only fitted about a week ago as the whole rig is brand new so I haven't had the chance to fit a safety rope to it and tie it to the A-frame just in case the worst case scenario happens!!

Nick Hearne · 23 June 2004, 15:17

Quote:

Originally Posted by swginn

Mine is attached directly to the transom just like gingercoastie's and alex's. It is a long shaft but sits well clear od the water. Its own tilt lock keeps it very rigid and no bouncing occurs at all. One handy thing is that the engine has adjustable steering friction which can be locked so that it doesn't turn in towards the main engine/ A-frame. This setup is very solid and works well for me. The engine was only fitted about a week ago as the whole rig is brand new so I haven't had the chance to fit a safety rope to it and tie it to the A-frame just in case the worst case scenario happens!!

Looks good but could you have not got the 2 engines color coded?
Nick

gingercoastie · 23 June 2004, 15:19

Quote:

Originally Posted by Nick Hearne

Looks good but could you have not got the 2 engines color coded?
Nick

I knew there was a good reason for buying Suzuki

swginn · 23 June 2004, 18:34

Yep I know!!, unfortunately Mercury don't do a Saltwater version of the 5hp. Might try hunt down a set of blue decals though!!

geoff · 25 June 2004, 18:51

I had a stainless steel mounting put in just ahead of the transom. Works really well for my Marina 4sail auxillary. Not too much bother to swing it over the side, although with a Yamaha as a main engine I only had to do it once when we managed to catch our own fishing line.