[PCW] Outboards

[L&S Kubis]

No problem with the questions -- I may not be able to answer all of them as
I am currently in Canada and my data is in OZ!!

The Ozzycat is a narrow beamed planning design as many of the Cats in use in
Australia are as they are mostly used for fishing which requires a good turn
of speed!! My particular boat weighs in at just over 7 tons with near empty
tanks . With tanks about half filled ( full tankage is 1500L ), the sweet
point for the boat is 15-18 Knt's, full out she will easily do 30Knt's but
you really don't want to watch the fuel consumption meters!!. My Yanmars
also sucked plenty of fuel whenever the Turbo-Chargers kicked in!!

The Suzuki's have a larger dia prop compared to it's competitors being 16".
The boat currently has a 20 pitch prop and is a little over prop'd and needs
some adjustment to get the rev's up a bit at the top end! I can't remember
the fuel burn but I think it was around 50-60L/Hr (total) with 2200 rpm at
16 Knt's. I have a 40 min trip up and down a river before reaching the ocean
which has a speed restriction of 6 Knt's. During this trip I generally run
on one engine and it burns around 16-18 L/Hr as I can remember! I can
confirm these numbers in a couple of weeks as I will be back in OZ!

I have the optional Suzuki extended shafts on the engines!! One word of
caution though is that the bottom of the hull at the rear has to be adjusted
when using outboards to improve the water flow above the prop as the boat
rotates slightly up when going faster!!!!.
The motors are mounted on pods which lower the engines as low a possible. I
have not had any cavitation problems to date even in fairly choppy water!! I
assume if I blast through some of the waves it will obviously have
cavitation at high speed but my Noosa Cat did too with fixed shafts and
props!

I wouldn't be worried about using outboards as long as the boat is designed
properly for them -- there are many fisherman and rescue boats who prefer a
big outboard even in big seas in the ocean!! The rescue boats go out in some
terrible weather and very nasty bar conditions using Cats fitted with
outboards!!

RE-use -- we generally go out and cruise around for weekends to a week out,
mostly at anchor overnight! Haven't had a chance to take it up the coast
yet! I'm told she should be good for about a 500 mile or so hop depending on
how hard one pushes her!

Hope this has helped!!

Cheers!
Lloyd



----- Original Message ----- 
From: "Robert Deering" <deering@ak.net>
To: "'Power Catamaran List'" <power-catamaran@lists.samurai.com>
Sent: Sunday, October 08, 2006 10:40 PM
Subject: Re: [PCW] Outboards


> Lloyd,
>
> Thanks much for the report.  I have a bunch of questions, so please bear
> with me...
>
> Could you please provide a little more info on your boat?  Is it a
> planing or dispacement hull?  Displacement?  What kind of speed do you
> cruise at?  What is your fuel consumption?  How do you use the boat?
> And the outboards - are the extended lower units an after-market add-on?
> What kind of props are you running?
>
> Thanks in advance - I've not been able to get much info on
> outboard-powered cats in your size range - most boat-builders I've
> talked to have been pretty dubious about using outboards on a boat that
> size.
>
> Bob Deering
> Juneau Alaska
>
> -----Original Message-----
> From: power-catamaran-bounces@lists.samurai.com
> [mailto:power-catamaran-bounces@lists.samurai.com] On Behalf Of L&S
> Kubis
> Sent: Sunday, October 08, 2006 5:40 PM
> To: Power Catamaran List
> Subject: Re: [PCW] Outboards
>
>
> I live in Australia, on the Gold Coast and currently have a 2004, 40 ft
> Ozzycat ( ex-Cougar Power Cat ) with a pair of new 250 HP Suzuki's with
> extended shafts on her and just love them!! Prior to this Cat I had a
> similar sized Noosa Cat powered by a pair of Turbo-charged 350 HP
> Yanmars.
>
> I must say I like the Suzuki's much better at this point in time. They
> are
> quieter, much smoother, offer more maneuverability on a narrow beam Cat,
> no
> fouling of the props, far more responsive to the throttle than the
> diesels,
> (a feature appreciated by all the fisherman when crossing the numerous
> bars), outboards just pop up should one hit a mud bank whereas the fixed
>
> prop is damaged or pulled out of the boat, boat beaches easily, etc!!
>
> Regarding use of Diesel fuel vs Gas --as was pointed out to me many
> times --
> there are more pleasure craft powered by gasoline engines than diesels
> and
> they seem to do well!!
>
> The electrical output of the Suzuki's alternators is down a bit from the
>
> Yanmars but I have had no problem keeping my generator-less boat going
> fitted out with inverters, a very extensive electronics suite  and a
> battery
> bank of almost 1000 AMP/Hrs.
>
> Re- hotwater, I use an on-demand type propane heater which provides
> endless
> amounts of hot water quietly!! My friend has had one of these heaters on
> his
> sailboat for 15 years without problems and he has cruised extensively!!
>
> Most of the Power Cats in Australia below the mid 30's in length are
> powered
> by outboards for these reasons, particularly those used for fishing and
> rescue purposes !!!
>
> The niggly part of using the outboards is that need to be flushed out
> after
> using them and tying up the boat for a while!!
>
> Nevertheless the new Suzuki's are great and many people are switching to
>
> them because of their reliability and performance.
> BTW -- I have no connection to Suzuki -- I'm just a happy user!!
>
> Cheers!
> Lloyd
>
>
> ----- Original Message ----- 
> From: "Bob Kupps" <n6bk@yahoo.com>
> To: "Power Catamaran List" <power-catamaran@lists.samurai.com>
> Sent: Friday, October 06, 2006 11:58 PM
> Subject: Re: [PCW] Outboards
>
>
>> Hello I had a 46' Wharram sailing cat with two four stroke 25hp hi
>> thrust
>> OBs.
>>
>>  In addition to the advantages mentioned I would add lighter total
>> machinery weight including the drive gear and fuel/parts compatible
> with
>> dinghy motor.
>>
>>  Much more significant disadvantages to the real ones already listed,
>> IMO
>> are:
>>
>>  1) Total useful load for the same cruising performance would be
>> difficult
>> or impossible to safely carry.
>>  2) Reduced reliability
>>  3) Fumes are a real hazard that must be dealt with some vigilance.
>>  4) By far the most important problem will likely be prop cavitation.
> Even
>> mounted on boxes which hinged down from under the cockpit seats, I
>> frequently had to slow down to rediculously slow speeds when motoring
> into
>> steep seas to avoid prop cavitation and the constant throttle handling
>
>> (and noise) can get tiresome quickly even with an autopilot.
>>
>>  Naturally depending on one's intended use, and the pitching
>> characteristics of a particular hull form,  these may be more or less
>> significant
>>
>>
>> Gary Stavrou <gstavrou@bigpond.net.au> wrote:
>>  May I invite your general opinions on the subject of outboard
>> engines. It seems to me that for a light displacement cat of about
>> 9-10.5m in length that a couple of outboard motors in the 60-90 HP
>> range would be hard to beat. The obvious advantages are:
>> 1. Lower initial purchase and installation costs.
>> 2. Cheaper maintenance.
>> 3. Keeping fumes and vibration out of the hull proper.
>> 4. Having more usable space in the hulls.
>> 5. Better manoeverability at slower speeds.
>> 6. Lifting the leg out of the water when moored.
>> 7. Less risk of propeller damage.
>> 8. Smoother, though higher revving, motors.
>>
>> Other than having hot water without a gas setup, better electric power
>
>> generation and that satisfying throb of a low-revving diesel I cant
>> see why the outboards wouldn't be the sensible choice. Gary
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