Fuel Economy for 60hp-70 hp Outboards??

[craigie]

I've just been reading the latest "Fisherman & Boatowner" Magazine and I was especially interested in a review on a "Markham Dominator 4900"
This particular "Cat" is only 4.9m long, has a towing weight of around 1500 kg's with outboards in the 50 - 70hp(max) range. It appears to be very versatile and suitable for Bay and offshore waters.

What has got me thinking is the fuel economy for such a rig, if fitted up with say 60 hp 4 banger Yammies or something similar ??

Was therefore looking for fuel consumption figures for donks in the 60hp (Yammies, Mercs , e-techs, etc) to say 75hp (same brands) to help ascertain what type of figures it would take to propell the 4900 along ???

Any Ideas guy's ??

Cheers
Craigie.

[lenm]

I've been doing a bit of reasearch myself as i have a small cat (4.7m) i want to fit out with twin 50's.
I have a copy of trailer boat magazine (July-August) which compares all the brands of motors 40hp (2 & 4 stroke) and their fuel economy at certain revs etc. I know this is smaller than the motors you interested in but it might give you an rough idea on what to expect and the advantages of each brand etc.
Another interesting thing i noted was the difference in some of the weights between the motor brands sometimes up to 20kg difference. Maybe something to consider also as they always suggest to keep the weight down as much as possible in a small cat.

[craigie]

Thanks for your reply "Lenm", I'll get hold of that Mag and check out the outboard tests.

I'm still keen to hear about your fuel consumption figures Guys, so let em rip 8)

By the way, does anybody own a Markham Dominator (I know Foxy does) who can comment on their ride/performance and handling.
Also, if anybody owns a similar size "Cat" around the 5m mark but a differnt make, I'd be very interested to hear your figures as well.

Regards
Craigie

[dfox]

G-day mate- i cant comment on the fuel figures of the 60 4strokes but id guess and say they'd be pretty bloody good, my 115s never sease to amaze me how efficent they run. As for cat hulls i can comment on the larger trailable ones, ive used mine in some truely dangerous seas and although i have had waves break right over me ive always had complete confidence in the hull and its performance. The hull is very capable and predictable and has no strange tendencies, it can slam a little hard when driven dirrectly into a head sea but this is usually because im driving to quick for the conditions, side on, to the quarter or with the sea it is simply unbelievable both in ride and performance, which means if you can drive out in ordinary conditions your going to come home in comfort.Ive been on the noosa cats, kevla cats, coogar cats, nustar cats ,coastal cats etc and all perform differently, and a careful study of the hulls will give you an indication of what each boats strong points are. Finer sponsens usually ride better into chop but may tend to bury more in a following swell. The middle of the road hull would be the late model noosa cat which i believe is a good compremising hull, the coastal cat is super fine in its design. The markham is the most advanced design, but this is not why i bought it. I liked its concept of lift and ability to carry large loads. Mine was the first of the latest model hulls in Qld and i had to research its abilities off several pros working in WA. It has exceded my expectations. The 7000 dominator has had over 100 made in the last 3 years. The smaller cats are said to perform far superior to any boat of equal length, and i wouldnt dought it...Ive owned and operated many boats and as far as trailable boats go for offshore a good cat is hard to beat.. hope im ive some help ...foxy

[SNELLY]

Craigie,

I have a 60hp Yammie 4st on a 4.6m Sea Quell mono and I get 2nm to the litre in good conditions at 30 - 35kn

Snelly

[craigie]

Snelly,

Thanks for the info mate. The 60 hp 4 banger Yammie would be the most likely donk I would fit to this boat (If I had the boat ;D) 2nm to the litre (3.6k's) sounds very good considering your high (30 - 35kn) cruise speed.
I read in F&B Mag that your motor will sit on a normal cruise speed around 4000 - 4500 revs for a fuel burn of 10 - 11 litres per hour, so if the 4900 Dominator was fitted up with them, it would be 20 odd litres per hour at a 3/4 throttle cruise speed.
According to the test date I was sent from Northside Marine, The 4900 was fitted up with 50 Hondas and pulled 38 m/p/h/, you would expect the 60 Yammies to pull low to mid 40's ???
A shame there are no light weight 70' 4strokes/DI's around as this boat would start to turn into a rocket ship ;D

Foxy,

I was hopfull you might stumble across this thread as I was very interested to hear your comments on the Markham Dominator cats. You obviously know your stuff and I value your opinion.
I agree mate, your rig is awesome :o :o Something we all aspire to one day 8).
I have read a bit about some of the other "Cats" on the market and they generally all get glowing reviews, with the Markhams right up there with the best of them.

The 4900 caught my eye due to it's "Towability" with a family sedan, Economy (twin 50 to 60 hp 4 bangers, fuel bill would be no more than my current rig with the very economical 115 merc Optimax), offshore capabilities at a very reasonable price compared to slightly larger cats that are available.

Anyone know what "Snappa"'s economy was like in his old mate "Kellogs" ??

Thanks again guys,

Regards
Craig.

[SNELLY]

Craig.

My average trip to the reef up here is 65 to 70 mn and as I said on a good day 34-35 litres. on a bad day it is over 40 litres. To be honest I have never tried to cruise out there on a good day as they as so few and far between. When it's flat I'm 5,000 plus and closer to 6,000

Snelly

[Sportfish_5]

Craig - They only come in white ;D ;D ;D ;D ;D

The latest trade-aboat magazine has some fuel figures for the new 60 EFI 4stk yammies. Will post them when I get home from Perth but they were good :P :P :P

There are a couple of pros running out of Moloolaba in Coastal Cats with these new 60hp yammies. Maybe Jeffo knows of them and could get some info.

Pete had a post about how much trips cost a little while ago so have a search and you might get a shock :o :o My old man owned one of the early fibreglass 20ft Shark Cats as well as a 16ft Alloy Cat with twin 40 mercs. That Alloy Cat was a hell of a boat when I think back about it :-[

[perko]

craige, I have had a 5.2 kevlacat with twin 70hp yamahas and now have a 5.5 sailfish with twin 70hp johnos, both 2 strokes. Fuel ecconomy a bit better on the alloy cat. We can do 80 mile (not nautical) for about 120 litres in the sailfish. The navman fuel flow meters say we are using 12-15 lph at 4000 - 4500 rpm which gives us 25 - 30 mph.
Have a friend that has a 5.2 kevla with twin 60 hp 4 stroke yamahas and his economy isn't a great deal better than ours. Still has a bit to do with the setup and the right power for weight. Another mate who pros out of Sunshine Coast has a 7m coastal cat with twin 70hp suzukis and he gets very good economy and still hits around 30 mph. Cats sure have there fans, and I know my offshore boat will always be a cat. Ventured back to monos a while ago but got back into a cat real quick. Tony.

[craigie]

Snelly,

30 - 35 litres for a 70nm round trip to the reef, ya gotta be happy with that :)
For some of the areas I would want to fish (Turkey Beach to Rock Cod Shoals and back, approx 50 ? nm) that would be a very economical round trip going on your figures :D.

Greg,

Bugga !!! only white, but i want Tangerine again ;D ;D
Might have to hunt down a copy of Trade-a-Boat and get a gork of those figures. I might just win powerball tonight and have to go full-on into purchase mode !!

Perko,

Thanks for your insight and comments.
I have been following your Boat choice plight through the "Questions" and "Letterbox" sections of the Fisherman & Boatowner Magazine. I remember reading your comments about going for a run in a Whitley and comparing it's ride to the 5.2 Kevla, I guess as the say, there is no turning back ;D Your Sailfish sounds like a very nice rig. Have been on the large Sailfish that "Mono" runs out of Brunswick heads. Twin 130 Hondas and so safe and stable.
Are you still donging a few Snappa on the Sunny Coast ?

Cheers
Craig.

[perko]

Craigie, mate haven't been doing much fishing of late. Not having much luck with the good weather falling on days we can fish. Also we are getting the sailfish ready to relocate up to our house at Turkey for a while, and trying to get a shed put up there (bloody builders/councils). I remember seeing the orange cyclone crabbing up at turkey last easter or something. We were stuffing around in the same areas in our 4.55 poly side console. When is your next trip up there planned for. We should be up there every weekend of good weather after christmas if everything planned falls into place. Will have to catch up with you one day. Tony.

[craigie]

Tony,

Was trying to tee-up a visit to Turkey in January, Maybe a long weekender or similar around Australia Day ?? I seem to recall Smithy and yourself getting a few trout ::) around that time earlier this year.

I have a mate named Scott, who's parents own a place in the back street, less than 100m from the ramp. They were one of the original squater families they came into the area back in the 50's ??, they were then balloted a block of land in the Early 70's ? when the council started to see the potential of the place. $500 got you one of those first blocks, and they were the ones around the Boat Ramp and Point that are now worth Mega $$$$
My first visit to the area was in 1988, not many houses back then and the whiting fishing in the bay was exceptional.
Still kicking myself for not purchasing a block of land a few years back when $20 000 went a long way :'( :'(

Now that I know your boats, I'll look out for you when I'm up there.

Oh yes, got some fuel figures on the new EFI Yammie 4 banger.
6.3 litre per hour at 3500 revs (clean plane)
7.7 '' '' ''''''' 4000 ''
11.7 '' '' ''' '' 5000
19.2 at WOT

A full write-up in Trailer Boat Mag, issue 186.

Cheers
Craig.