THE OFFICIAL BUTT CAT FAN PAGE
- Thread starter FishExcutnr
- Start date
benniejordaan
Sealiner
FishExcutnr
Sealiner
BFC wrote:
Spoke to the owner the other day at seaport. seems very new to fishing. it was his first trip out and he abslutely just cant believe how amazing the boat rides! they got there first yellowin on a blind strike after losing 3 fish weighed 35-40kg max so little shoaling fish.
he had 85 yammies which were under gunned and said 115s were perfect combo. gear box failure occured due to a failure in installation but i will not speculate on this forum.
nice to have another new kamassi butt cat in the cape. should have put suzukis on and would never had had the problem !
685 Butt cat came in today from the deep running 2x Brand new Yamaha 115's just past Rocky bank on the way in Starboard motor blew a gearbox , needless to say crew was not full of smiles taking 3hrs back to Harbour Island on one motor.
Luckily they are still under warrantee
Spoke to the owner the other day at seaport. seems very new to fishing. it was his first trip out and he abslutely just cant believe how amazing the boat rides! they got there first yellowin on a blind strike after losing 3 fish weighed 35-40kg max so little shoaling fish.
he had 85 yammies which were under gunned and said 115s were perfect combo. gear box failure occured due to a failure in installation but i will not speculate on this forum.
nice to have another new kamassi butt cat in the cape. should have put suzukis on and would never had had the problem !
Georgy wrote:
It is my understanding that, in terms of outboards, Honda developed Lean Burn some time ago and was awarded a 5 Year International "Patent". They have been marketing this technology as "ECOmo". The Patent has now expired which is why Suzuki and others are able to use the same tech.
Essentially,Lean Burn Control technology allows combustion to operate on a leaner air/fuel ratio than stoichiometric air/fuel. An O2 sensor, together with the ECM, precisely controls the air/fuel mixture for the best fuel economy at cruise setting.
I can't tell you what the actual difference is in fuel consumption though, but it must be a worthwhile percentage for the manufacturers to go to the trouble of incorporating the technology into their motors.
It is my understanding that, in terms of outboards, Honda developed Lean Burn some time ago and was awarded a 5 Year International "Patent". They have been marketing this technology as "ECOmo". The Patent has now expired which is why Suzuki and others are able to use the same tech.
Essentially,Lean Burn Control technology allows combustion to operate on a leaner air/fuel ratio than stoichiometric air/fuel. An O2 sensor, together with the ECM, precisely controls the air/fuel mixture for the best fuel economy at cruise setting.
I can't tell you what the actual difference is in fuel consumption though, but it must be a worthwhile percentage for the manufacturers to go to the trouble of incorporating the technology into their motors.
Thika, I would not mind playing around with props. Sounds like you have a lot of power. Truth be told, I was running closer to 4800 revs, kept the revs under 5000. Not that I'm set on watching the speedo all the time and 4 guys versus 6 would make a slight difference. I also carried around 350 liters of fuel. I think I have 21P props on, very stupid when it comes to that and take advice from suppliers, so would be interested what you would suggest I run, maybe I can find some and test it.
Georgy,
If you do 46 kmh at 4800, and assuming at WOT you should be able to make 5500 RPM, then your max speed will be 53 kmh or 29 knots.
This is a bit slow, but then again, you have a big boat, and maybe I am barking up the wrong tree
It comes down to fuel economy. An outboard runs most economical at 3800-4200 RPM
At 4000, my boat does about 28 knots
My bare hull is 1500 kgs (Ace Craft
) and I carry 260L fuel, so heavier than you I think. I have 130 2stroke Yammies
That's why I think you are underpropped
I am also no expert with props, but go see on your hubs what it says. Also see what WOT max revs you can make on still water and report back (I think you have about 17 inch pitch by the sound of it), and then take it from there.
You sometimes need speed with big SW swells behind you, and you also don't want to be over revving unless you are a rich man!
PS: You have a lot of wind resistance on that boat
If you do 46 kmh at 4800, and assuming at WOT you should be able to make 5500 RPM, then your max speed will be 53 kmh or 29 knots.
This is a bit slow, but then again, you have a big boat, and maybe I am barking up the wrong tree
It comes down to fuel economy. An outboard runs most economical at 3800-4200 RPM
At 4000, my boat does about 28 knots
My bare hull is 1500 kgs (Ace Craft
) and I carry 260L fuel, so heavier than you I think. I have 130 2stroke YammiesThat's why I think you are underpropped
I am also no expert with props, but go see on your hubs what it says. Also see what WOT max revs you can make on still water and report back (I think you have about 17 inch pitch by the sound of it), and then take it from there.
You sometimes need speed with big SW swells behind you, and you also don't want to be over revving unless you are a rich man!
PS: You have a lot of wind resistance on that boat
Top speed on my boat when Suzuki tested it with Leisure Boating Magazine was 65km per hour. I usually run at around 58. I will check my props when I am down at the boat again, but I think I have 21's. I don't like revving high, not that kinda cowboy so not sure I will be reporting back about max revs, but thank you for the advice. I do know that ideal would be stainless props but I am happy with my performance and I would be surprised if swell ever outran me even if I could only do 20knots.
FishExcutnr
Sealiner
I run at 4200 rpm, 7 up , 350 litres fuel, 500kg gear, do 24-26 knots. Top end used to be 40-1 knots before fitting hydro foils to the engines to counter some cavitation, it worked, now top end 36-7 knots but no cavitation.
Top end means buggers all, you will never run it because you cant in a normal sea and because you just waste juice!.
Butt cat 760 likes to run 28knots at 4600 rpm, but she is more economical at 4000-4200 rpm.
Propped with 21 stainless, 3 blade. Boat gets on a plane like a jet.
fuel consumption 2- 2.2 L / nm.
These are all accurate stats.
Top end means buggers all, you will never run it because you cant in a normal sea and because you just waste juice!.
Butt cat 760 likes to run 28knots at 4600 rpm, but she is more economical at 4000-4200 rpm.
Propped with 21 stainless, 3 blade. Boat gets on a plane like a jet.
fuel consumption 2- 2.2 L / nm.
These are all accurate stats.
FishExcutnr
Sealiner
FishExcutnr wrote:
Yeah to be honest I pretty much only run that speed when you hit the flat water from Smits to Simon's Town.
Yeah to be honest I pretty much only run that speed when you hit the flat water from Smits to Simon's Town.
Some advice guys, I have been looking around for a butt cat for some time now and I think I have found what I am after, I specifically wanted a 21' boat as I tow a fair amount, Cape Town to struis and wanted a boat that would not be scared of running to the deep with. I have attached a picture, I am wanting advice on layout. I would like to put a cabin/wheel house, I don't want to cover the whole front of the boat as I enjoy the option of having a guy able to spin off the front but would also like to get out the spray hence the reason for wanting to change from a cc. I like the 670 GF type layout, is there anyone in Cape Town that is able to do a similar type cabin as this? I have a contact for a wheelhouse but would like to compare options.
Any help would be appreciated.
Any help would be appreciated.
