Use the mounting bracket on the motor to know where it will sit on the boat. Displacement hulled vessels like sailboats and workboats can benefit from a little more space between the hull and cavitation plate, but not much. Be sure to measure carefully and research thoroughly before diving in. The 20 inch versions from the 50's and 60's, of no more than 40 hp, always had an adapter piece added to the "leg" of the engine. The shaft length of an outboard motor is the distance between the anti-cavitation plate (the metal plate horizontally above the propeller) and the motor mount (the lowest point of the propeller). Generally for a sib, it's a short shaft engine you'd required, basically measure from the top of the transom to the bottom of the keel, this will tell you what length of shaft is required, f-ribs, Honwaves, zodiac, and the vast majority of Sibs run short shaft. The strength of the water flow. Needs to be mounted. While also ensuring the following: - The hull is not blocking the water from reaching the propellor, which means it operates at maximum effectiveness.
Converted to a 20 inch version, and also the other-way-around? One of the great things about an outboard motor is how versatile it is. This article discusses the difference between long and short-shaft outboard motors and the effects of the wrong shaft being installed. You will also risk hitting bottom or submerged objects more frequently such as rocks. Our L is longer than L from Mercury.
Anyway, that's my take on the subject and I wouldn't really want to have to draw any conclusions from it at this point. If you have a fast boat, getting the outboard's cavitation plate at the same level of the hull will ensure quick hole shot and fast top-end speeds. The information on this page will narrow down the importance of shaft length and will give you an idea of what type of motor you should buy for your boating application. Read my other articles on outboard motors. Even at 3" there would be more serious modifications needed than a spacer on the top of the transom.
Boat name: April Lass. 20-30 years ago 4-strokes were heavier, but not today. While the outboard motor isn't something, you change regularly, knowing the type of water you will use it in is helpful. Your looking at a long shaft motor. In the photo at the link below a long-shaft is used but it is also a 20' canoe. Many boat transoms are modified to use a different length of outboard by using a bracket. However, why struggle to measure transom height or guess the ideal outboard shaft length when you can check the boat's manual? If your boat planes, pay extra attention to getting the shaft length as close to perfect as possible.
My last attachment cut off some of the question and answers in the Faq's section. Ideally, you want the outboard's cavitation plate, also called the anti-ventilation plate, to be at the same level as the bottom of your hull. Boats, outboards designed for 25 inch transoms began to be. Joined: Tue May 08, 2007 2:27 pm. High powered boats usually only come in long and extra-long variants. If we run into that scenario, I would still show you the different options of motors and go over pricing, but I would also ask you to hold off and do one thing before you pull the trigger. With a compact design and weighing in at only 24kg (short shaft) these new outboards are incredibly versatile and with class-leading technical innovations and some simple, yet effective, ergonomic design features, these new models are incredibly easy to live with. Measure straight down to the lowest point on the hull. These allow the mounting of a standard length outboard behind the transom.
Has an adjustable bracket can I put a short shaft motor on it? It will ensure that the outboard's trim will be effective, and it will save you gas too. Explore America's Campgrounds. Smooth and quiet running thanks to an offset crankshaft. The actual wooden plate for motor is plumb, which is good, but the boat transom is slanted. Even with those adjustable brackets, The long-shaft, 20" (or even x-long shaft, 25") will allow keeping the powerhead higher above the water than you can with a short-shaft. That's not to say however that the aux cannot be switched to also run from the main tank, or vice versa (main engine from aux supply) but just that the primary supplies for each engine should be wholly independant. Don't forget to ensure turning clearance for your main engine when the auxillary is in both up and down position. Most of the abovementioned long shaft outboard boats will work well with a standard 20 or 25-inch (50. There no serial number or anything so I don't know for sure. Picking the Best Small Outboard Motor. Click images to enlarge.
Depending on the motor model, the new shaft may be installed and the wiring shortened to match. For boats equipped with a bracket, calculate the same measurement but based on the bracket and not the transom. NO modification are needed. Clutch (clutch dog). Boats with smaller motors need to steer at higher speeds, which makes a shorter outboard shaft ideal since outboard engines turn completely as the boat changes direction. But since you're probably in deep shit already by losing the main engine with the QM2 bearing down on you, you rather want to be able to start the little begger and give it some ASAP. Get the riser, determine the thickness and beef up your transom to fit. However, since the shaft length correlates directly with the boat's transom height and size, it's best to follow the manufacturer's recommendations. MEASURING AND SELECTING GAS OR ELECTRIC MOTOR SHAFT LENGTHS. Joined: 07 Nov 2017, 20:24. But unless you've something like a Zodiac bombard or futura, chances are you need a shorty.