Auxiliary outboard

Glenn collins · 12 June 2010, 18:52

I was out Tuesday in the Thames estuary doing my RYA intermediate when the school boat had an engine problem. The alarm for low oil sounded and it reverted to low revs. We managed to limp home on the main at tick over without worry as the boat (7.5 picton rib with 200 yam) was fitted with a 4.5hp auxiliary.

This got me thinking if iwas out and about in mine and engine problems left me stranded would I really want to make "that" call.

Ok so I only have an SR4 but am thinking of some form of redundancy by way of a small auxiliary outboard or electrick outboard.

In relation to best option, fitting and space, size and power etc... What would your thoughts be.

Glenn

Adam Brimage · 12 June 2010, 19:21

Quote:

Originally Posted by Glenn collins

I was out Tuesday in the Thames estuary doing my RYA intermediate when the school boat had an engine problem. The alarm for low oil sounded and it reverted to low revs. We managed to limp home on the main at tick over without worry as the boat (7.5 picton rib with 200 yam) was fitted with a 4.5hp auxiliary.

This got me thinking if iwas out and about in mine and engine problems left me stranded would I really want to make "that" call.

Ok so I only have an SR4 but am thinking of some form of redundancy by way of a small auxiliary outboard or electrick outboard.

In relation to best option, fitting and space, size and power etc... What would your thoughts be.

Glenn

You will find that it is very hard to attach an aux engine and bracket onto a rib. We have the same problem, but thankfully where we go we have assistance from the sailing club safety boats, because my dad used to run them.

BogMonster · 12 June 2010, 19:49

Quote:

Originally Posted by Adam Brimage

You will find that it is very hard to attach an aux engine and bracket onto a rib.

Eh?

Rather depends on the rib ... I always carried an aux on my Humber and will be doing the same on the Vipermax.

Nos4r2 · 12 June 2010, 20:27

Yep, I used to run an aux on my Sr4 as well.Straight on the transom.

Glenn collins · 13 June 2010, 07:34

Quote:

Originally Posted by Nos4r2

Yep, I used to run an aux on my Sr4 as well.Straight on the transom.

What was it, size n power and was there any space or balance issues.

G

bedajim · 13 June 2010, 07:47

I fitted a 4 hp to my SR4 put the bracket on the bottom of the A frame

And have a 15 hp on the Vipermax

Nos4r2 · 13 June 2010, 09:16

Depends on your setup as to what'll fit straight onto an sr4. If you don't have an A-frame, you'll just about get an old 4hp Evinrude like this (but the shortshaft version) on there but make sure the prop can't hit the tubes. I put one on when I first got mine, but when I changed the main engine the 4hp no longer fitted in the gap between my engine and A-frame

The one I used more was an old 2hp Evinrude like this as it fitted easily. The single transom clamp screw made it easier to fit. Got 4 knots out of it flat out in flat calm.

No balance issues with either. They weigh very little. I suspect the balance was helped by my main engine being mounted centrally rather than offset to port, but with engines that small you can counter by moving the fuel tanks.

Ally S · 13 June 2010, 12:19

ive got an sr4m - main engine is a 4 stroke honda but we have a 2 stroke 4 hp suzuki attached directly to the transom alongside it. pushes the boat along just fine if needed.

The honda has full steerage in both directions, the suzuki has limited movement in one direction, but you can always steer with the larger engine leg.

Downhilldai · 13 June 2010, 14:02

I have a 4hp Evinrude std shaft, like the one in Nos's pic, if anyone's interested in buying it. £175

Glenn collins · 13 June 2010, 14:30

Quote:

Originally Posted by Downhilldai

I have a 4hp Evinrude std shaft, like the one in Nos's pic, if anyone's interested in buying it. £175

Pm sent

9D280 · 14 June 2010, 10:47

Looks like we could have an "Evenrude Aux"parrty.....I had one of the 2Hps on the SR4, and have a longhsft 4 on the Humber.

Other nice lightweight one is the 3.5 Hp Tohatsu (also re- badged by pretty much much everyone else at some point in the last 20 years) 3 on Fleabay at the mo......

spartacus · 14 June 2010, 11:27

Quote:

Originally Posted by 9D280

Other nice lightweight one is the 3.5 Hp Tohatsu (also re- badged by pretty much much everyone else at some point in the last 20 years) 3 on Fleabay at the mo......

That's exactly what I had on my Zodiac Pro. Bit industrial - but does the job. Only went for the two-stroke because the 4-stroke is wider and heavier. One note of warning is that it needs addional support on the tilt bracket (and a ratchet strap to maintain tension on it) - as it frankly isn't up to the job bouncing up and down on the transom of a RIB! A Yamaha 4hp (2-stroke) would be a good buy too.

9D280 · 14 June 2010, 14:32

At least it's got a support bracket, which is a lot more than those Johnsorudes do........

One thing I don't miss form 1970s OMC - "friction tilt lock"

Nos4r2 · 14 June 2010, 14:53

Quote:

Originally Posted by 9D280

At least it's got a support bracket, which is a lot more than those Johnsorudes do........

One thing I don't miss form 1970s OMC - "friction tilt lock"

Yep.

Bungee round A-frame is how I used to hold mine tilted

9D280 · 15 June 2010, 07:40

...and in the absense of an A- frame you need about 4" of 2x1, an 8mm drill and some bungee.

Drill the wood , loop the bungee a copmlete lap of the leg just below the powerhead, then tie two figure 8 knots having tensioned the bungee and passed it throughthe two holes in the wood. For "run" you swivel the wood out the way (the fin halfway down the leg stops it getting to the prop). For "up" swivel it round & lift into the gap 'tween clamp & swivel. the corner on the swivel bracket holds it in place nicely. A further length of bungee tied to the clamp & looped round the leg holds the engine down onto the wood. (ensure that loop is short enough to not meet the prop when running, although not too difficult as the bungee stretches).