Which outboards for me ?

[Dave_S]

Hi

I have a Schionning Waterline 1480 (48') they are a performance sailing cruising catamaran it weighs around 7 to 7.5 tons loaded up.

I'm in the market for 2 New engines.

The existing are Yamaha 25hp high thrust, they are underwhelming - 8.5kn flat out no sails. The recommended motors are 40 hp.

My choices are very limited if I only choose from the high thrust list.

1/. Can I use std thrust engines.

• Will I loose much control in low speed docking
• Is it to hard on the gearbox
• Can I fit large diameter prop with less pitch

2/. Which engines would you recommend, I am leaning towards the Honda but in high thrust options 30hp isn't much of an upgrade and I think the next one up is a 60. Mercury have a half measure available on many sizes - anyone with experience with these?

I would like smooth easy controls and some ECU feedback on revs and fuel consumption. No carburetors.

Any feedback is good.

Thanks

[SV DestinyAscen]

Suzuki outboards seem to be A great pick. Fuel injection and great fuel management.

[westwinds]

I would stay with high thrust outboard. The propeller and reduction gears will already be matched. You may also have a problem with propeller stalling if pitch is too much, as would be required for planing hull.
Yamaha does have a high thrust 50 horsepower outboard. Specify Optional Dual Thrust™ Large Diameter Propeller on high thrust 50 horsepower outboard.
High-Thrust Features | Yamaha Outboards

[westwinds]

By the way, is there room to have two Yamaha 25hp high thrust on each hull for a total of four outboards?

[clockwork orange]

So if the recommended motors are 40hp, these would not be high thrust, right? Why not use what the designer recommends? Why not contact the designer for his input?
With your current motors 8.5 knots does not seem too bad imho, would this not be comparable to diesels.

[crabcake]

Originally Posted by SV DestinyAscen

Suzuki outboards seem to be A great pick. Fuel injection and great fuel management.

ROCK SOLID! Can get them serviced and parts for them all over the world.

I don't know if its still the case, but they were the largest producer of outboards in the world.

[Dave_S]

Originally Posted by clockwork orange

So if the recommended motors are 40hp, these would not be high thrust, right? Why not use what the designer recommends? Why not contact the designer for his input?
With your current motors 8.5 knots does not seem too bad imho, would this not be comparable to diesels.

I might be wrong but I assumed the 40s were HT but not available now. I spoke to Schionning and they said a number of people are using 30s but don't get much improvement over the 25s - makes sense.

I want to have an improvement if I am going to spend the money. How disappointing to spend all that on new engines just to go the same!

Mercury do a 40HT but it is a de-tuned 60 so it weighs 118 kg dry.

I'll have a look at Suzuki, I hadn't thought of them.

Thanks

[Cadence]

Originally Posted by Dave_S

Hi

I have a Schionning Waterline 1480 (48') they are a performance sailing cruising catamaran it weighs around 7 to 7.5 tons loaded up.

I'm in the market for 2 New engines.

The existing are Yamaha 25hp high thrust, they are underwhelming - 8.5kn flat out no sails. The recommended motors are 40 hp.

My choices are very limited if I only choose from the high thrust list.

1/. Can I use std thrust engines.

• Will I loose much control in low speed docking
• Is it to hard on the gearbox
• Can I fit large diameter prop with less pitch

2/. Which engines would you recommend, I am leaning towards the Honda but in high thrust options 30hp isn't much of an upgrade and I think the next one up is a 60. Mercury have a half measure available on many sizes - anyone with experience with these?

I would like smooth easy controls and some ECU feedback on revs and fuel consumption. No carburetors.

Any feedback is good.

Thanks

Honda four stroke high trust are a little pricey but good and also quiet. I would not even consider anything but anyone's long shaft high thrust. JMHO

[Cheechako]

The Suzukis are good. Find ~ the HP you want. Also pay attention to what props are available for what engine you chose. Most these engines are propped for planing hulls. You want to be able to find props for a displacement hull usage.

[Cadence]

Originally Posted by Cheechako

The Suzukis are good. Find ~ the HP you want. Also pay attention to what props are available for what engine you chose. Most these engines are propped for planing hulls. You want to be able to find props for a displacement hull usage.

The long shaft high thrust models are made for displacement hulls basically sail boats. I wouldn't swear to it but think they probably are geared differently and can swing a larger wheel between the shaft and the cavitation plate ?

[Cheechako]

Originally Posted by Cadence

The long shaft high thrust models are made for displacement hulls basically sail boats. I wouldn't swear to it but think they probably are geared differently and can swing a larger wheel between the shaft and the cavitation plate ?

Yes I understand, but they don't make those in 40 HP do they? So you are likely going to want to de-pitch to run them at an rpm they are comfortable with....?

[hamburking]

Have you considered going electric? The motors are relatively small and powerful with constant torque over a wide range of RPM. Add a small generator in each hull to provide the juice. There would be several advantages of this...moving the weight inboard, electric motors require no maintenance/oil/lube/etc, and the possibility of quiet operation when approaching a dock/anchorage by running off battery for a couple minutes. And you get tons of electrical power generation as a bonus...maybe you already have the generator aboard, which would make the install even easier.

IMHO, electric is the future!
(slam me if you must, but only time will tell for sure)

[brianlara 3]

The right person to be asking is Schoinning himself. He's not far away in Port Stepens. Same time zone as you.
Surely his advice nas to be best. IMHO.

[brianlara 3]

Displacement speed is limited to 4/3 Pi x R squared right? So at 8.5kt you are getting close to that number.
The only reason your boat "sails" much faster than that is because you're planing.
And even 40 HT motors may not enable planing. (surely not ??).
A lot of money for another knot perhaps??
At 8.5 you're already motoring faster than a Maritimo 50 if at displacement speed.
Have I got it wrong?
Schoinning will know.

[Dave_S]

Originally Posted by hamburking

Have you considered going electric? The motors are relatively small and powerful with constant torque over a wide range of RPM. Add a small generator in each hull to provide the juice. There would be several advantages of this...moving the weight inboard, electric motors require no maintenance/oil/lube/etc, and the possibility of quiet operation when approaching a dock/anchorage by running off battery for a couple minutes. And you get tons of electrical power generation as a bonus...maybe you already have the generator aboard, which would make the install even easier.

IMHO, electric is the future!
(slam me if you must, but only time will tell for sure)

I did get a quote and specs from Ocean Volt in the hope that electric would fit but it just doesn't work for me. I agree that they look like the future but I think it's too early.