Trimming a boat correctly is critical in maximizing efficiency, reducing fuel usage and also improving ride quality. Most boaters do this by “feeling” the boat under them, but there is a much better way of doing this.
 |
| Fuel flow meter |
The use of fuel flow instruments is critical in determining the best trim position as it gives you fuel usage and does not rely on subjective “feel” from the skipper.
An example of this was done by a friend of mine who was operating 2x B150 Honda outboards. Whilst under way and operating at normal cruising speed, the fuel consumption for both engines was 56 litres per hour.
Trimming the engines up and down without touching the throttles and reading the fuel flow gauge, the fuel consumption went from 56 litres per hour down to 39 litres per hour. Overall, this is a savings of approx 30%, just from adjusting the boats trim while monitoring the fuel gauges.
??
??
Although fuel flow meters will more accurately provide details about trim position and fuel economy, they will not always be viable or practical in small tiller steered vessels. People with smaller boats need to spend time testing their boats by adjusting the tilt pin to suit the conditions that they normaly operate in. By adjusting the tilt pin, the attitude of the boat when underway will change the thrust line of the outboard resulting in two things – improved performance (fuel and speed) or less performance.
An additional option to improve performance is to fix a Hydrofoil stabilising system to your outboard cavitation plate. With boats that are stern heavy, by providing max lift at the outboard using a hydrofoil, you can adjust the trim angle of the boat with greater efficiency.
The key is finding the tilt angle that best suits your regular load and usual conditions.
Another problem with incorrect load distribution (too much weight aft) is "porpoising."
Porpoising is the name given to the forward and back motion some boats make while riding on the water. Picture a porpoise leaping through the water and you get the idea. It may be fine for them, but its murder on a boat’s performance, comfort and safety. This action is actually caused from too much weight at the back of the boat. In other words, incorrect weight distribution. This pounding causes many people to ride only in the very back of the boat. With correct load distribution and the use of Hydrofoils, this can correct this action, providing you with more comfort, safety and performance.
Ensuring the correct propeller choice is crucial for fuel economy, top end speed and hole shot (getting the boat out of the water at start up) unfortunately, many boat owners worry about their speed at a certain RPM when they should be more concerned about their outboard operating within the recommended range in which the outboard has been designed. Setting up to achieve a certain speed at a certain RPM is like pissing fuel into the wind. It usually results in an outboard not performing optimally across the RPM range for fuel and performance either in the bottom or top end range. Many boat owners go down the path of sourcing non-genuine props, believing it is the only way to go to gain improved performance. Unfortunately, any changes made to the boat for example load, application or configuration, the performance will change and it possible that a different prop will then be required.
To best assist you, I suggest it pays to seek advice from your outboard manufacturer through their dealer network of which you’ll need to provide the size of the prop, pitch diameter and max RPM with regular load, the mounting height of the outboard and your opinion of its performance in turning situations and hole shot. With this information, the dealer will be able to advise a prop that will deliver an improved result.
Setting up your boat for maximum efficiency isn’t easy. There more to it than prop, motor and boat.
Gross weight, weight distribution, motor height, weather and sea conditions all play a part, but I hope this has given you a few things to think about when it comes time to use your fishing rig. By being sensible with how you set up, use and power your rig, you might find that you have extra money in your pocket at the end of the day.
Have a good one
Mark
Tonys Cruise Control 5.2 build Hi Mark,
A couple of photos of the transom showing the extenion for the longer outboad leg [25in], with a bit more sanding I will be ready to put some high build on and paint.
Regards
Tony
?
If youd like to see more of Tonys Cruise Control 5.2 build, please visit of BoatBuilding Forum
To see more of the Cruise Control 5.2 design or more of our range of designs, please visit our website
--------------------------------------------------------------------------------------
Kens Mushulu 14 Gday all,In the last couple of nights Ive got the front seat/storage in and cut out the transom.
It looking more like a boat with everything Im doing now.
My son & I will turn it over on the weekend, so I can glass the outside of the hull.
regards
Ken
If youd like to see more of Kens Mushulu 14, please visit of BoatBuilding Forum
To see more of the Mushulu 14 design or more of our range of designs, please visit our website
-----------------------------------------------------------
Grahams SporzMaster 19
Hi,
Heres a few more pictures.
I am fitting a 12 v windlass hence the change of access to anchor well. If it plays up I will be able to stow the rope from inboard making it safer.
The floors will be of Paulowina 14mm and the front 2 deck soles are ready for glassing and stiffening the undersides.
I was able to organise the scuppers using 45 degree fittings you need 400 mm + between Station 11 and the transom to fit and glass them.
Picked up a Suzuki 140 hp 2 stroke for a steal (22 Hours on the clock) so if you see a BLONDE Headed !!! geriatric hooning at 45 knots + that’s me.
Cheers
Graham
To see more of Grahams SportzMaster 19, please visit of BoatBuilding Forum
To see more of the SportzMaster 19 design or more of our range of designs, please visit our website
-------------------------------------------------
Mathews Mushulu 14 G’day.
All done!
When I painted the floor white it made the area look so much bigger. The mod’s worked out how I’d pictured it in my mind – very happy with the end result.
Not sure if I want to put forward steering - I like the idea of ‘floor space’.
Anyway, happy building, boating and fishing everyone.
Kind regards,
Mat.
??? ????
????
If youd like to see more of Mathews Mushulu 14, please visit of BoatBuilding Forum
To see more of the Mushulu 14 design or more of our range of designs, please visit our website
--------------------------------------------------------------------
See you next week with our latest weekly news and other articles ! Thanks for visiting our website?????????????http://www.bowdidgemarinedesigns.com/ are you looking for? If not, below may help you find more information about the Boat Plans Nz. Thank you for visiting, have a great day.
