Aux engine - Page 2

jeffstevens763@g · 24 July 2018, 10:13

dont want to get into the debate over size hp or should you have one, but biggest problem i found was room as already stated my old rib 6m ribquest with a 90 hp on it had very little room for an auxiliary engine the biggest i could fit was a 4hp possibly 6 hp due to cowling size it also meant i couldn't steer with it because it had to be hard against the A frame i did have it on a bracket [solid] but that meant leaning back to steer around the A frame not ideal in rough conditions, the best compromise i found was to set it as is in the pic and steer with the main engine in good conditions it would achieve 5 knots WOT i did have an external tank for it so to get good range and little need to keep filling the fixed tank.
i never considered it as a get me home more of off the rocks or to stop drifting further OMO

pauldee007 · 24 July 2018, 10:33

Quote:

Originally Posted by paulb33

With new RIB heading for service (RedBay 7.4m Suzuki 250) so begins my questioning (sorry). What are folks thoughts on aux engine set-up?

I see much debate on merits (or otherwise) of an auxiliary engine contingency. Having taken a “belt and braces” approach to the purchase (buy new and buy long...), my instinct is to carry an aux engine (as much for my passengers’ peace of mind). The kids know Dad is absolutely the type of dullard who drains a battery while fishing.

Again, I’m happy to invest cash up front on bullet proof kit that will see me through ten trouble-free seasons (until the kids have flown). Safety trumps all.

I sense this post screams “naive newbie” and “a fool and his money” but all pointers would be welcome.

I've always carried an aux engine, currently a 5hp 4 stroke merc on the back of a 6.5m rib. I test it once in a while in the Solent and it's enough to get the boat out of the way of ferry's / ships etc. Peace of mind with the wife and kids on board that's for sure.

Having towed two broken down boats this season, one out of the way of ferry between Lymington and yarmouth (one with fuel contamination, the other quite new with a damaged gearbox after hitting something), no one would ever change my mind on carrying an aux engine no matter how new your kit is.

paulb33 · 24 July 2018, 10:56

Quote:

Originally Posted by pauldee007

I've always carried an aux engine, currently a 5hp 4 stroke merc on the back of a 6.5m rib. I test it once in a while in the Solent and it's enough to get the boat out of the way of ferry's / ships etc. Peace of mind with the wife and kids on board that's for sure.

Curious if one of the new-fangled electric outboards would have served this purpose?

paulb33 · 24 July 2018, 11:01

Quote:

biggest problem i found was room

i never considered it as a get me home more of off the rocks or to stop drifting further OMO

Would one of the new dangled electric outboards have been a better choice, I wonder.

Last Tango · 24 July 2018, 11:58

Quote:

Originally Posted by paulb33

Would one of the new dangled electric outboards have been a better choice, I wonder.

For this specific scenario it would have been "as good" I can't see what would have made it "better" and even getting 30mls home is a realistic possibility with a petrol aux O/B.

I've seen situations where AIS is showing nothing for 16mls. What leisure boats that may have been around (there were none in sight) are far more likely to be sailing boats...not ideal for towing a broken down RIB so really, there would be no way out that didn't involve contacting the coastguard because they're the only ones that are going to pick up your VHF transmission.

Compared with the overall cost of boating a small aux outboard is a drop in the ocean....I've burnt more in petrol in a week than a second hand 5hp would cost and it buys a lot of "peace of mind"

GuyC · 24 July 2018, 11:58

Looking at it slightly differently.

I have a 3.4m Zodiac SIB that I'm planning on using as a tender for my RIB. It has a 15HP Mariner engine which will also double up as an aux engine should I need it.

The Torqueedo (electric) motor would be an interesting option. A quick look on line suggests they do a 8HP version which might be enough for what you need. It's pretty expensive but relative to the boat and the kids, probably not too bad. I'm sure it could be kept charged via the main engine and it's half the weight o an equivalent petrol engine.

paulb33 · 24 July 2018, 12:03

Quote:

I have a 3.4m Zodiac SIB that I'm planning on using as a tender for my RIB. It has a 15HP Mariner engine which will also double up as an aux engine.

So.......are you taking the SIB on board with you? If so, how?

A tender is also on my to-figure our list, so interested in this option.

willk · 24 July 2018, 12:05

Quote:

Originally Posted by paulb33

The kids know Dad is absolutely the type of dullard who drains a battery while fishing..

That's where your old coding helps - she should have a pair of gel batteries on a split/share switch. One for the engine, one for the electronics. The engine charging will be prioritised for the starter battery.

willk · 24 July 2018, 12:32

Quote:

Originally Posted by paulb33

It seems that RedBay sit in Fender’s camp. They can’t recall ever fitting one...and question whether it’ll even fit.

I suspected that might be their take on it. I was trying to imagine how an aux would sit in beside the mighty Suzi and the boat be workable.

You'd need something in the region of 8-10hp, pull start, probably a high thrust prop, maybe a very solid bracket on the exterior of the transom, some means of steering, means of supplying enough fuel. You'll also need to confirm heights so that you get the right length shaft. It will sit out there and get kicked about and constantly be in your way. You'll need a means of securing it against impact and theft. If you ever need it, it might push you along at 4-5kts - if you can steer accurately at those speeds.

A lot of engine issues come back to fuel and battery. I put a lot of work into both. Charge batteries when ashore, check fuel filters for water, carry spares, treat fuel, etc.

IMO, if one broke down off the west coast with kids and wife aboard, an aux is fine and dandy, but a call to the CG would be highly advisable in any case. Once they hear there's a boat full of "non-combatants" making 4kts east they'll task some assets anyway. That's their take on it, and I'd be inclined to agree with them.

DanExe · 24 July 2018, 12:53

Quote:

Originally Posted by spartacus

Sorted.

https://www.gumtree.com/p/boats-kaya...tor/1307124343

Buy it and get it on a pallet. Replace gear oil, pull cord, sparks, etc. Possibly one of our Ribnet colleagues down south can check it out and do a compression test?

FWIW, although I don’t know the engine myself, if you do decide this engine is the right choice for you... I can 100% vouch for the honesty and integrity of this seller.

He’s a retired tech/engineering teacher who has serviced my engine for years and specialises in restoring and maintaining portable weight outboard engines.

Also, well known locally, for an un paralleled ability to source and provide excellent secondhand Tohatsu 9.8 2T’s too.

Contact him through gumtree or pm me, if you would like his number.

paulb33 · 24 July 2018, 13:04

[QUOTE=willk;777964]

This makes VERY good sense. Thank you.

Nos4r2 · 25 July 2018, 09:17

I wouldn't be without an aux. Had to actually use mine last week when a fuel pump relay went south in Southampton Water, stopping the Opti dead.

FWIW, the Yam 8 (shortshaft version of the one on Gumtree) will push my 7.8 at about 6 knots. Also makes my 2.8m sib go like the blazes

Poly · 25 July 2018, 21:42

Quote:

Originally Posted by spartacus

Sorted.

https://www.gumtree.com/p/boats-kaya...tor/1307124343

Buy it and get it on a pallet. Replace gear oil, pull cord, sparks, etc. Possibly one of our Ribnet colleagues down south can check it out and do a compression test?

That’s premix though isn’t it? Not ideal for a rarely used engine, when the main engine is a 4 str.

If the OP is considering a tender it may be good to kill two birds with one stone - if he can find one to suit/mount on both with the right length. Any engine the right size should have a pull start (even if it also has electric) do not sure that is something to focus on. If you are lifting it on/off then weight will matter.

beamishken · 26 July 2018, 11:20

Quote:

Originally Posted by Poly

That’s premix though isn’t it? Not ideal for a rarely used engine, when the main engine is a 4 str.

If the OP is considering a tender it may be good to kill two birds with one stone - if he can find one to suit/mount on both with the right length. Any engine the right size should have a pull start (even if it also has electric) do not sure that is something to focus on. If you are lifting it on/off then weight will matter.

Id have thought an old school 2 stroke like that would be ideal for infrequent use. Far less likely to suffer running problems due to carb issues from little use and easier to fix if it does.
Never seen a oil injection at that size but carrying a dedicated fuel supply isnt a bad idea if fuel contamination is the issue with the main
That yam is very light for a 2 cyl 8 and a gutsy little engine
I'd have that over a 4 stroke any day for an aux
4 stroke carbs are far more complex and therefore more prone to fuel issues. For the purpose simple is best Imho

paulb33 · 26 July 2018, 11:21

I’m curious about an electric Torqeedo that can serve both the tender and RIB. That helps with weight and fuel issues. Putting cost issue aside (for now) what are views? https://www.electricoutboards.eu/cru...ts-c2x22282972

Last Tango · 26 July 2018, 11:49

Range is going to be an issue. If you're loading it up pushing a heavy rib it'll cane power from it's batteries and you'll not get far.

5hp = approx 3.7KW. that's about 300amps at 12V . Theoretically that'll take out 100AH battery in 20 mins.

(in reality it wouldn't last anything like that long)

Fenlander · 26 July 2018, 12:11

>>>Range is going to be an issue.

Indeed... I looked into these for sibbing… sorry can't not mention cost!

Under load or trying to do any distance even a fully charged OE battery might last just an hour so you'd probably want to carry two. But they weigh 24kg each and cost an eyewatering £2200 each... plus £370 for the charger.

So the total cost for motor, batteries and charger is £7600 and in all you'd be carrying an extra 68kg.

Makes a clean used 8hp 2-stroke around £800, under 30kg with easy to source/carry fuel look very attractive.

But if you were short of transom space and blessed with very deep pockets.....

Nos4r2 · 26 July 2018, 14:53

Quote:

Originally Posted by Poly

That’s premix though isn’t it? Not ideal for a rarely used engine, when the main engine is a 4 str.

I wonder... On my Opti I chuck the 12L premix into the main tank every 3 months or so and refill it (12l of 100:1 in 200+ litres makes very little odds)

Can you do that on modern 4 strokes without an issue?

Last Tango · 26 July 2018, 14:59

Quote:

Originally Posted by Nos4r2

I wonder... On my Opti I chuck the 12L premix into the main tank every 3 months or so and refill it (12l of 100:1 in 200+ litres makes very little odds)

Can you do that on modern 4 strokes without an issue?

You could.....but it might smoke a bit.

jeffstevens763@g · 26 July 2018, 15:14

Quote:

Originally Posted by Nos4r2

I wonder... On my Opti I chuck the 12L premix into the main tank every 3 months or so and refill it (12l of 100:1 in 200+ litres makes very little odds)

Can you do that on modern 4 strokes without an issue?

i do it with the lawn mower as said just smokes a bit well a lot, bit of top end lube not going to hurt that, dont know about doing it with fuel injection affecting the injectors