What Aux?

[jezza2011]

gramas. sorry got my paragraphs mixed up. :-) was aimed at spareribs. ;-)

[clydeoutboards]

Hi

the honda that has been mentioned is more than enough. these push a shetland 570 at 4-5mph depending on tides and it comes in a 750kg. its also air cooled so great for the sea as the smaller engines suffer from sucking up **** and salt deposits and it is the lightest in its class in the world. Comes with a 6 year warranty new and is under £600.00 or 2nd hand of flea by 6 years or older for around £400-£425.00.

oh and they will be on the water at the Scottish boat show in two weeks time on honwaves at the inverkip marina if you want to see one in action or dont trust this advice.

Dave

[Anchorhandler]

Originally Posted by spareribs

you wont get a sensible answer on here mate, not one that I would trust , phone up the rnli and ask them, at least its from the horses mouth. You dont know who's who on here. All you'll get is a load of mixed opinions from people who think they are all experts. This site is really an SEO operation for rib related firms. If someone on here has a 5 hp engine for sale , they will say 5hp etc. You get the picture !

I wonder if they say that to the contestents on " Who wants to be a millionaire"?......" FFS dont trust the audience for an answer...they all think their experts"...

Yes, maybe but when 85% of the audience agree on something then there's probably a good chance that they may be right...

Same aplies on here...if 12 people say to use a 2-3.5 hp outboard but 2 people say you need a 25hp minimum then.....well you get the picture.

BTW, I feel you need a minimum of 8hp which funny enough i will be putting one up for sale shortly...

Simon

[Poly]

Originally Posted by spareribs

you wont get a sensible answer on here mate, not one that I would trust , phone up the rnli and ask them, at least its from the horses mouth. You dont know who's who on here. All you'll get is a load of mixed opinions from people who think they are all experts. This site is really an SEO operation for rib related firms. If someone on here has a 5 hp engine for sale , they will say 5hp etc. You get the picture !

Spareribs - why are you hanging about here is its pointless?

Mixed opinions are useful, because very few things in life are absolutely clear cut. With a little intelligence its usually possible to see if someone is pushing a particular agenda, or has an unsubstantiated view which is at odds to the rest of the community. As Anchorhandler says if 85% of people agree its probably a good indication. If you only ask one person at the RNLI you'll only get one answer, doesn't mean its right. Being on the RNLI crew doesn't make you an expert in ribs or boat safety necessarily. Even being an RNLI sea safety adviser (not that I have a problem with them) doesn't mean you have any real practical experience of ribbing in the sort of way you plan to use your boat.

Originally Posted by Gramas

What aux do you think id be best using? Rib is 4.5metres so do i get small 3/4 hp 2 or 4 stroke or an electric with good thrust power, oars or call rnli for tow back in should the main break down???

There is a rule-of-thumb which has been popularised on here which is 1HP per metre of length. Although for practical / space reasons many people will be constrained to using something smaller which might limit their options in strong currents (but still give more control and choice than waiting for a tow!).

Electric is not really feasible for an Aux: only the very expensive torquedo's have an integral battery - and you should assume your main boat battery is part of the problem with the main engine. Even the biggest torquedo isn't going to move a 4.5m rib very fast and will probably not last as long on a single charge as a 4 HP and a 5L can of fuel.

Oars (need rowlocks of some sort) or paddles will be ok in a sheltered harbour but I can't imagine using them to any success with 1m waves even to get 1/2 a mile back to shore. However if 90% of your trips will be in busy areas, or with friends then the aux might be unnecessary - just buy a good tow rope.

The 2 v's 4 stroke question will depend on storage. 4strokes are awkward to store (don't like lying in certain ways) and are often "fatter" on the transom. Do you have space to fit it permanently on the transom and still steer the engine? A frames often get in the way. Do you have space to store it (upright?) elsewhere on board? Can you imagine manhandling it on the transom rolling around in a 1m+ swell? If you are inclined to go wave hopping rather than gentle cruising

A preferred option here for a long aux trip is to set up the aux in a fixed ahead position, set the throttle and then return to the helm to steer using the main engine as a rudder. Beware the main engine will add considerable drag and only provide wide turns but its preferable to siting perched on the tube trying throttle and steer for a couple of hours.

[tony t]

Originally Posted by willk

Electric is not up to that job. Paddles are only of limited use for short distances in still current-free water but worth having on board. A 3-4 hp engine would most likely be ideal - check what space you have (turn main engine - check clearance) and how long the shaft needs to be. You might get away with a short shaft on that size of RIB - depends.

Whatever you do, do not be tempted to use an old plasterer's mixing rod and a battery drill...

I'm a plasterer if any wants a mixing rod I have loads in working order ... Take no notice of Willk or that muppet spareribs

[Pikey Dave]

Originally Posted by tony t

or that muppet spareribs

Spareribs Aux Cheap to run

[Anchorhandler]

Originally Posted by tony t

I'm a plasterer if any wants a mixing rod I have loads in working order ... Take no notice of Willk or that muppet spareribs

I think what Willk was refering to was actually the issue of the battery drill not lasting very long....quite obviously you need a portable generator+220v drill and then us a plasterer's paddle.... You can then make a cuppa too....

Simon

[willk]

Originally Posted by Anchorhandler

I think what Willk was refering to was actually the issue of the battery drill not lasting very long

Yeah - no need for Plasterers to start Stirring it, or sticking their Oar in...

[Pikey Dave]

Originally Posted by Anchorhandler

I think what Willk was refering to was actually the issue of the battery drill not lasting very long....quite obviously you need a portable generator+220v drill and then us a plasterer's paddle.... You can then make a cuppa too....

Simon

The best way to go, would be to have an inverter running off the boat battery, run the paddle mixer off the inverter & have a battery charger plugged into it too to charge the battery, simples

[tony t]

Originally Posted by Anchorhandler

I think what Willk was refering to was actually the issue of the battery drill not lasting very long....quite obviously you need a portable generator+220v drill and then us a plasterer's paddle.... You can then make a cuppa too....

Simon

Mate ... Us plasterers have arms like Popeye who the fook needs a battery to turn the paddle

[HUMBER P4VWL]

Originally Posted by tony t

Mate ... Us plasterers have arms like Popeye who the fook needs a battery to turn the paddle

Well, the ones that do the plastering for the Rib cruising bosses do anyway

Domino runs very well on 4 stroke plaster mixers from what I've seen. (Thumbs)

Poly's on one tonight! Must have learnt to touch type.

[clydeoutboards]

Originally Posted by Anchorhandler

I wonder if they say that to the contestents on " Who wants to be a millionaire"?......" FFS dont trust the audience for an answer...they all think their experts"...

Yes, maybe but when 85% of the audience agree on something then there's probably a good chance that they may be right...

Same aplies on here...if 12 people say to use a 2-3.5 hp outboard but 2 people say you need a 25hp minimum then.....well you get the picture.

BTW, I feel you need a minimum of 8hp which funny enough i will be putting one up for sale shortly...

Simon

well said Simon and I have changed my mind as I was thinking that you should not follow everyone else as I was playing lemmings last night and the all died because that's what they did.

so after ages of thinking this through....

you should buy 2nd hand ones as you can never be to safe and if your aux fails as well as your main engine that could be the end of of you.

funny enough just like Simon I have 2 in stock and just to be extra extra safe you can have my old plaster mixer as well so that way 3 engines could fail and you will still get back.

[9D280]

Originally Posted by spareribs

you wont get a sensible answer on here mate, not one that I would trust , phone up the rnli and ask them, at least its from the horses mouth. You dont know who's who on here. All you'll get is a load of mixed opinions from people who think they are all experts. This site is really an SEO operation for rib related firms. If someone on here has a 5 hp engine for sale , they will say 5hp etc. You get the picture !

What you absolutely must have is an old Johnson 1975 4Hp Longhshaft in Light blue livery with an Evenrude cowl top in dark blue livery drilled because the choke on the '75 engine was at the opposite side to every other year of production and a modified clamp to go round your towing eye in the old 60's khaki green colour. I have one here for £5K - £4.5K & it's yours!




Ok, being serious, Gramas, for a rib that size, you are realistically looking at 3-5Hp. If you travel places with big currents, lean towards the 5 end. Long Vs short shaft, plenty of people where you lauch will probably allow you to borrow their aux for 2 mins to hang on your transom to see if the prop comes anywhere near the water

I can (just) use a short shaft on mine - IF I sit on the back toob - otherwise the first sign of a wave & the prop lifts out. Longshaft I can sit on the seat & the prop stays in.
As Poly & others have said, transom height is the decider there. (and remember a Longshaft small Hp engine is shorter than a Longshaft "big" HP engine).

[mister p]

Mr Spareribs,
When I started reading your initial post, I agreed........you aren't very likely to get a "serious" response.
What you will get is one (many) based upon experience. You distill the answers and draw your conclusions.
Do you know Mr Squidward?
And have you got a Defender that you're selling?

[TomKat]

by way of slightly useful input a 2.2HP 2 stroke Yamaha Malta was not enough to push my 4.8m rib against any wind or current - on that basis I would say at least 4HP. The other thing about the really small OB's is they tend not to have gearboxes which I found to be a nuisance as you cant warm them up easily to be sure they will start when you need them to.

[bedajim]

I run a 15 2st long shaft on a custom made bracket
With separate 25 l portable fuel tank
I also use it in very shallow water to protect the main
It's pulled a couple of Vipermax's along from a shallow anchorage to deeper water
Jim

[9D280]

Originally Posted by bedajim

I run a 15 2st long shaft on a custom made bracket
With separate 25 l portable fuel tank
I also use it in very shallow water to protect the main
It's pulled a couple of Vipermax's along from a shallow anchorage to deeper water
Jim

Yeah but you have " Length: 7m+" - 15Hp could be the main engine on a 4m!


Tomkat does have a point tho'. I used a 2 on mine for about 2 outings. Outside the marina it was remarkably close to a chocolate fireguard, admittedly partly due to the shaft length (or lack thereof).

As for the warming up, the small engines are designed to be started & used from cold. Once you get into 4-ish Hp territory some have a simple "stop - go" clutch, and some have full F-N-R. THing wioth F-N-R is there is usually a big lever on the side, that if you have an A- frame suddenly might fill the extra 3 inches clearance you don't have! Mine is "on or off" - not even a clutch, but at anything below about 1/3 throttle it has as near as no forward thrust anyway, so it can be started, brought back down to idle & might as well be in neutral.

I "brass necked" a couple of "can I borrow your aux for 2 mins to see if it fits" moments to see what engines would & wouldn't fit. Well worth the time spent, coz what the paper data doesn't tell you is where the bulge in the case (max width) is...



I think I'm safe in summarising here that get as many gee gess as you can fit on, and the rest is down to your preference / transom geometry.

[Downhilldai]

Bear in mind the max transom weight of your RIB when you choose an aux o/b.

A popular choice for 4+m RIB is the Merc/Mariner/Twatsoo 3.3/3.5hp 2-stroke. I use one on an SR4.7 and it moves the boat at around 4-5kts. They're lightweight, narrow and reliable, so tick a lot of boxes in the 'Which aux motor?' debate.

[whisper]

Originally Posted by Downhilldai

Bear in mind the max transom weight of your RIB when you choose an aux o/b.

A popular choice for 4+m RIB is the Merc/Mariner/Twatsoo 3.3/3.5hp 2-stroke. I use one on an SR4.7 and it moves the boat at around 4-5kts. They're lightweight, narrow and reliable, so tick a lot of boxes in the 'Which aux motor?' debate.

[9D280]

Originally Posted by Downhilldai

Bear in mind the max transom weight of your RIB when you choose an aux o/b.

A popular choice for 4+m RIB is the Merc/Mariner/Twatsoo 3.3/3.5hp 2-stroke. I use one on an SR4.7 and it moves the boat at around 4-5kts. They're lightweight, narrow and reliable, so tick a lot of boxes in the 'Which aux motor?' debate.

+1.

The only downside to all those boxes being ticked is finding one!