What Size Auxillary should I get?

[Skipsta]

Due to the fact that 3 out of my last 4 trips has resulted in my engine experiencing problems and barely limping back to shore, (Problem was water getting into my fuel-problem sorted now ;) ) I have decided that I should get a small auxillary motor. A secondary reason is I like to troll a bit and my 90hp 2 stroke Yammy hates to idle for long and she runs too fast as well.

My boat is a 5.2m Plate Alloy Centre Console with the aforesaid 90hp yammy.

My question to Ausfishers is, "What size engine should I get"

Cost is a consideration but not a huge one. Major considerations I have is 1. Will it push me along to get out of trouble and 2. will it be too heavy on the starboard side of my boat, ie any problems with lean?

Denzill from Karee Marine reckons a 5hp 2 stroke is all that I will need for some trolling and get me home in an emergency.

Australian Master Marine reckon I should get something like a 15hp.

I reckon either engine would get me home in reasonable conditions and I don't believe either engine would help me negotiate the return on a bar even under ideal conditions.

Any advice or experinece would be appreciated. :)

Photo attached.

[billfisher]

I'd go for the 15hp. You might get away with a 10hp but in most cases there is no weight difference between the two. A 15 hp should push your boat at 5-6 knots. They can cause a slight lean to you boat but it is usually not too hard to counteract it my putting heavier items of gear on the opposite side. Your boat is not a really deep V as well so it should not lean too much.

[2iar]

I'd go for the 15hp. You might get away with a 10hp but in most cases there is no weight difference between the two. A 15 hp should push your boat at 5-6 knots. They can cause a slight lean to you boat but it is usually not too hard to counteract it my putting heavier items of gear on the opposite side. Your boat is not a really deep V as well so it should not lean too much.

Billfisher's right in that there's no deifference in weight between 9.9's or 15's, and quite often the 15 is cheaper. There's also a Tohatsu 18 that's approximately the same weight. You're talking, from memory, about 32 - 38 kg's, so it should be easy enough to counterbalance (maybe with a dual battery or spare fuel tank for the aux for example). Remember though that by doing this, you'll have added up to 75Kg to the back of your boat, which might not be ideal with the rest of the payload.

Trolling speed might also be a consideration - you might want as low as 3/4 or as high as 8 depending on what you're chasing.

If you definitely decide to go for it, buy an aux plate and try to borrow one from a mate with a tinny. The only problem you might have here is that the tinny motor is normally short shaft, and your hull might be better off with a L/S.

Good luck,
Mike

[billfisher]

The counteracting weight doesn't have to be at the back of the boat. It can be well forward and on the opposite side to the auxillary. You can use a shortshaft if you have one of those spring loaded drop down auxillary brackets.
I have a Tohatsu 18hp on my 5.4m glass boat and it is a very powerful little motor.

[Skipsta]

Thanks guys, a great start and great advice. #I am picking up the following bracket today. #

Deluxe Outboard Bracket Cat. 750 BIAS $178.90
For motors to 20hp. 330mm from transom. Plastic pad 190mm wide at top x 290mm high. Transom space 130mm x 220mm high. Spring lift.
(See Pic Below.)

I thought it would be better than the gal or stainless steel one which were cheaper. #It handles up to 20hp, so I can leave my options open for the moment.

2IAR you were right. #Here are the prices of the Mercurys.
5hp - $1366
6hp - $1571
8hp - $1666
9.9hp - $2441
15hp - $2193

I'm now leaning towards either the 8hp or 15hp. #They seem the best value for money, but there is $530 difference between them. #The 8hp would be easier to manhandle, but the 15hp is twice the donk.

I'm not necessarily sold on the Mercs, that's just the ones I have the price for so far. #I am lucky in that my boat leans ever so slightly to port normally, so a bit of weight on the rear starboard can only be a good thing, and further to that, when at rest the boat is also slightly down at the bow.


Any chance of a pic of your set up Billfisher?

I'm after people's personal experiences of how different size motors (auxillaries) push different size boats and hoiw they have gotten the owners out of trouble.

Thanks in advance all #:D

[blaze]

bit late now but I would have weld a aux bracket on, I have a 18hp merc on my 20 footer Glass (never had to use it, but)
cheers
blaze

[billfisher]

Mines got me home a few times. I have had the steering on my main motor break twice at sea and have had a few other problems over the years. Its also handy for trolling live slimeys dead slow to save oiling up my big 2 stroke. I don't get more than 6 knots out of it, but rough weather doesn't seem to slow it down. I'm thinking of changing the propellor to a high thrust one more suited to auxillary use.
Another tip is not to rely on the tilt lock to keep it raised but drop it on to a block of wood held with bugee cord on either end.
I'll post a few picks when I get a chance. I just bought a digital camera so it will be a good chance to learn how to use it!

[Skipsta]

Ok then, AMM have gotten back to me and have said that they do not believe that it is viable to attach the aluminium auxillary outboard bracket on as the head (top) of the motor would be too low to the water and the head would be swamped. #I said that I though the thing was height adjustable, but they said this did not matter. #

They have offered to fabricate a second auxillary bracket to the transom, just like the main one only smaller. #Problem is that this involves welding so the under floor tank needs to be removed etc etc $$$$. #I have been quoted $650 to do this, re-paint etc. #Unfortunately this blows the budget out quite high.

I have attached a photo (The only one I've got as the boat is at AMM) #It is of the boat whilst it was being made. Looking at attaching the motor on the starboard side. #What are your thoughts on whether this Bias bought bracket could be effectively fitted to hold an auxillary. #If it can be fitted I will save around $430.

Looking for thoughts from those Ausfishers in the boating/manufacturing industry #:)

Cheers

Skipsta

[fishingrod]

On your rig i would go 8-15hp.

Ive got a 15hp 1999 Merc on my 17" Cruise Craft. Its a long shaft on a height adjustable bracket. Its a fully stainless bracket made by Tenob #OU01. Its a very strong bracket and i highly recommend them. http://www.tenob.co.nz/bracket.htm
It looks like they have another adjustable bracket that can mount flat on your pod. Bias or Whitworths has the OU01 and most dealers can order the others thru their wholesaler.
You need to make sure your prop is deep enough in the water so it doesnt get cavitate in rough weather. A short shaft may be ok with an adjustable bracket.

I have a high thrust prop on my aux and i can get 7-8 knots flat out and cruising at 5-6 knots without reving its balls off. It still gives reasonable forward motion even on a very windy or rough day.

My Mercury does not allow me to trailer (or travel in rough weather at speed) with the motor fully tilted up. The manual states that the bracket is not strong enough. You need to buy an additional quicksilver fitting to allow the motor to get pounded around when fully tilted. Otherwise you need to have it on the highest shallow water drive position. (see fishnet link below)

Ive used mine twice to get out of trouble. Once to go from Collaroy to Brooklyn (approx 25 miles/half offshore/took 4-5 hours) and from Gladesville to Ermington (inside Sydney Harbour). Its VERY reassuring knowing that if anything happens you can come home under your own steam. By all means get a tow if you can but if there is no tow available you are 100% self sufficient.

If i was doing it again i may look at a 4 stroke if they are not too heavy. This would eliminate the need to carry 50:1 premix and have it go stale. If you can use straight unleaded you can run it in your car or main engine once its say 3 months old. Make sure you carry a DEDICATED fuel tank and fuel line for the aux. 10-20 litres is normally enough depending how far you need to go.

If you plan to troll at 4-6 knots you will find that a small motor may be reving pretty hard and may give an annoying scream. The main 90hp might actually be quieter and easier on the ears as it is just puttin away. If you are doing DST (dead slow troll) stuff the small motor is ideal.

This forum has some info on a couple of 15hp brands:
http://www.fishnet.com.au/forums/viewtopic.php?t=44450

A piccy of my rig is at http://i31.photobucket.com/albums/c369/fishingbasket/rodsboat2.jpg
But it doesnt really give a good view of the bracket

sorry for the long post !
cheers
Rod

[fishingrod]

OK more pics if they help.

Once on the plane the skeg on the aux is a few cm clear of the water and does not drag.

Ive got a transom step under the aux bracket and i use a rope (orange rope in piccy) to lash the motor down so i can bounce and pound as much as i like as it doesnt wobble or vibrate.

Sorry about the bad quality :(
http://i31.photobucket.com/albums/c369/fishingbasket/aux2.jpg
http://i31.photobucket.com/albums/c369/fishingbasket/aux1.jpg

[blaze]

Hi Rod
I too face the delemer about premix for the aux motor going stale, what I do is carry the remains out of the 5l bottle when I top up my oil tank in the boat and if I need to use the aux it only takes a few momments to put it in, then after every couple of trips I tip it in the main tank and refill the 20l tank for the aux
cheers
blaze

[fishingrod]

G'day Blaze
Yep, we have all got our own systems. I do it a little similar to you.
I have 3 tanks. Call me a freak but this works for me and is pretty flexiable. I got fuel lines so i can mix and match a few combinations or giggle syphon.

80L plain unleaded underfloor
5L 50:1 premix portable
20L plain unleaded portable
+ 1L of spare 2stroke oil

The 5L of premix means that i can flush the aux after each outing and also means i can start it quickly if i break down in a hairy position. Its only a few litres so its pretty easy to use up or dilute with plain fuel and run thru the main motor if it gets more than 3-4 months old (or pour on ants nests :P)

It might sound a bit dicky, but it works for me and i can keep the fuel rotating without any wastage. If im taking a few people out i might leave the pre mix at home to save space and simply mix up if i break down the same as you do.

Ive recently discovered that some outboard oils are suited to air cooled motors too. Quicksilver label indicates that i can use it in my cheapo 50:1 generator 8-)

When petrol in Sydney hit $1.40 i just used the 20L in my car until the p*icks dropped the price again. Its only a couple of bucks per tank, but its the principle of paying $1.40 i was against

cheers
Rod

[Skipsta]

Because I am a cautious person and don't mind spending a few extra dollars for a quality job, I think I will be paying the money for AMM to fabricate a new bracket. btw I was mistaken, they are not removing the tank, they are going to fabricate, paint and bolt a bracket on the transom. $650 is a bit steep, like most AMM products, but with them you do pay for quality.

Then I'll be throwing a donk on the bank from another marina. Still haven't decided whether Yammie or Merc or 8 or 15. Guess there'll be some deliberations with the minister for war and finance.

Thanks for the effort guys. ;D