Trimming in, trimming down, and trimming out are all terms that a beginning boater should learn. This is handy if youre shopping for second-hand outboards or looking to sell the one that came with your boat. (function () { If you are running a slower boat, the exact location of the ventilation plate is less important. His works have appeared in regional newspapers in North Dakota and in "North Dakota Horizons" and "Cowboys and Indians" magazines. If mounting directly to a boat transom: Measure from the top of the transom down to the bottom of the hull or keel (lowest point). h[0].appendChild(s); For slower boats, its less critical to. Since the length of the shaft of your outboard is associated with the size boat, smaller engines will generally have shorter shafts. What Kind of Fuel Does Your Marine Engine Need? Assistant Measuring tape Grease pencil Ask a friend to hold one end of a measuring tape at the extreme outer edge of the top of the transom while you pull the tape across its width to the opposite outer edge to measure the "length of the taffrail," which is the width of the boat across the top edge of the stern. While this is the case there is certain saltwater motors that are extra extra long at 30. If your outboard motor height. Attention: Remember to measure the outboard shaft length straight up and down instead of measuring along the transom. Knowing the width, height and depth of your transom allows you to make several important decisions when selecting or purchasing a new outboard. One of the great things about an outboard motor is how versatile it is. These cookies will be stored in your browser only with your consent. You can order an outboard in lengths ranging from 15 inches to 30 inches, depending on its power output and possible uses. %PDF-1.7 }) } }); })(document); If you have a jackplate, you may have to get a bit creative in your There is a simple test to see if your outboard motor is set at the best height. Ideally, you want the outboards cavitation plate, also called the anti-ventilation plate, to be at the same level as the bottom of your hull. Knowing how this can affect the overall operation of the boat is a factor to be considered. Any owner seeking the last bit of speed from an outboard-powered boat should grab a yard stick. Eq*^?6R83e+j}UY.(M7k]~4g)g ~wmS{ O7t/o(W|X? var BCData = {"csrf_token":"d7ecb6b56891bb66aee12dbc01a80162b3ed582c1acbe30f16fc9f1b2abc362f"}; The most common percent angle is probably 12, however spec sheets for O/B and I/O boats may show 10 percent, 12 percent, and 14 degrees. Boat hulls are designed in three basic types that range from slow displacement and semi-displacement hulls to the fastest planing hulls. I also love helping others, which is why I created this website. Picking the right shaft length is mostly a factor of the transom height or the back of the boat. Your goal is to measure how the outboard will sit, so start from the clamping plate and follow the centerline of the hull. What are Apple Podcasts Subscriptions and Channels? Owners of bass boats, RIBs, or offshore fishing boats need to get this right. } Most of the standard engined boats it takes shafts that are 15-30inches long. Outboards designed for saltwater applications usually have longer shafts. As a result, the issue is whether my boat need a short shaft or long shaft motor. Rebuilt - What You Need to Know, Lower Unit and Sterndrive Break-In Instructions. Copyright 2017 Dealer Spike All Rights Reserved. enableMoreInfoLink: true, The transom is the back of the boat where the motor is hung. For boats equipped with a bracket, calculate the same measurement but based on the bracket and not the transom. The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. This allows the engine to idle without the flow of the exhaust being restricted. Some boats are equipped with transom-hung outboards while others have a bracket. Some fishing boats can handle the motor being underwater. Raising the motor increases the speed of the boat while decreasing the effort needed to turn the boat. In the case of a dinghy or johnboat, this point may be the top of the transom. As you can see, the measurement is about 2 1/2". This was the height of my 225 Yamaha on my TR21 Plus, a low transom cut is an invitation for the water to flood the boat. Recommended Engine Oil 2-Stroke Outboard Motor Oil. If it measures 15" or with in a inch of that you will need a short shaft outboard. As with anything, there are exceptions to the rule. You run the risk of possibly unsafe handling if you attempt to put a long shaft engine on a transom designed for a short shaft engine. The engine must be linked to the transom at the proper height for a propeller to best meet specific boating demands. Check out the Westshore Marine & Leisure Youtube page! With such an important, long-term, and expensive upgrade, its never a bad idea to double-check. If youre going the other way around and trying to figure out how long the shaft on your outboard is, measuring it is equally easy. ), and place it on the bottom of the pad in the center. Commonly, the transom angle ranges from 0-30 degrees, with the average transom angle set at 14 degrees. They operate as a planing surface, allowing your boat to climb to the top more quickly. It is unsafe to have the engine block too close to the water on a low transom. document.getElementById('cloakd53b59933f6c3f2e8b59f1b4a6d41fa5').innerHTML = ''; The lowest point will likely be directly under your drain plug if youve got one. What is the Virtual Sundance Film Festival? Place the clubs bottom on the ground as though it were going to be used to strike a golf ball. When trimming your motor, they provide you a greater bow response. Basically, there are three main ways to measure motor Ill also explain the difference between short and long shafts and how they vary by type of boat. Or it can have an angle degree as high as 30. Why wont Touch ID be under the screen in the iPhone 15 and iPhone 16? But, how do you measure it? In lower mounting, the engine is set lower than the recommended standard. These cookies track visitors across websites and collect information to provide customized ads. With this in mind, how can I determine if my outboard has a short or long shaft? Brackets are also handy for boats that do not have flat transoms, like canoe-stern sailboats or fan-tailed motor vessels. In the photo above, we've measured from the motor bracket to the top of stream The outboard comes with mounting holes and brackets. It is very versatile as it generally . var xmlHttp = new XMLHttpRequest(); If you have a fast boat, getting the outboards cavitation plate at the same level of the hull will ensure quick hole shot and fast top-end speeds. They keep water out of your prop and increase water pressure in the system. This could also affect your travelling capabilities on the boat trailer. Outboard Motor Shaft Length: How do I measure? s.setAttribute("rel", "stylesheet"); Take a long straight edge, (long carpenter's level or long However, the motor should not be raised more than 5 inches above the standard position. 3 0 obj There is a simple test to see if your outboard motor is set at the best height. parallel with the straight edge. Measure from there down to the top of the cavitation plate, also known as the anti-ventilation plate. former editor at Boating Magazine and contributor to many national publications Step 3: Add another 10 cm (4'') to the previous calculation for the final ideal shaft length. s.setAttribute("type", "text/javascript"); This number will likely be shorter than that for a single-engine installation since you do not necessarily measure to the point of the keel. straight edge from the center of the pad, but this time you're measuring Doing this can have adverse effects. Small motors built for sailboats might come in a unique configuration with an extremely long shaft since these are mounted higher off the water. Triton. You dont have to be a mathematician to determine the correct boat transomangle. The flat part of the bracket that rests on the transom when mounted will give you the same point of reference as the transom does on the boat. Of course, its always best to go with standard practices when choosing thebest boat engine. Then test the boat and adjust the height, if necessary . Move the bracket as close to the center of the transom as possible while still maintaining clearance to allow the main outboard or rudder to reach its full range of motion without contacting the kicker motor. loadScript(ptScript); In step 3, add another 10 cm (4") to the previous calculation in order to develop the ideal shaft length. This cookie is set by GDPR Cookie Consent plugin. If the propeller fails to ventilate, the motor is mounted to low. Simply start with the engine in idle, followed bytrimming the motor out by one-half to full trim. (Putting a 4 0 obj Copyright 1999-2023 Boats Group. Selecting the Correct Size Outboard Shaft, What is the Best Outboard Motor for Saltwater, Diagnosing Common Outboard Motor Problems, Best Beginner Boats Everything You Need to Know. And the rule of thumb is that you should keep the cavitation plate level with the bottom or keel of the boat. s.setAttribute("src", script); Two years ago, I bought a Boston Whaler to fish off the coast. This alone can outweigh the negatives when deciding to adjust the mount upwards. Cavitation plates are used on the bottom components of boats to help them operate better. 7. The motor length corresponds to the transom height of the boat, measured from the keel to gunwale at the transom. While this is the case there is certain saltwater motors that are extra extra long at 30 and 35 shaft. This will keep the prop in the water when the boat pitches in waves, or hobby-horses. If you said you have a pontoon or a larger style boat such as a bass boat or speed boat, I would be pretty confident in saying it needs a long shaft. So you should just measure the height of the boats transom from the center down to the lowest point of the hull, and compare transom height with the outboard shaft length numbers. Well, raising the outboard motor can be an easy task for you. The boater must also consider if the boat transomsupport is designed to bear the weight of a higher mount. For vessels with transom-mounted outboards, you can easily figure out which type of outboard you need to get. If youre looking for a bracket that can handle motors of up to 10/15 horsepower, go no further. on How to Measure Outboard Shaft Length: The Only Guide You Need, ePropulsion vs Torqeedo: An All-Round Comparison, 55 lb Thrust Trolling Motors: All You Need to Know Before Purchase, Spot Lock Trolling Motor: Is It Worth It & Best Options in 2022, Wiring 24V Trolling Motors: 24 Volt Wiring Diagram (with Video), LiFePO4 Battery: Why Lithium iron Phosphate Batteries Are Your Best Options in 2022, Minn Kota vs MotorGuide: Best Option in 2022. } Raising the motor increases the speed of the boat while decreasing the effort needed to turn the boat. The rearmost structural member of your boat, it not only distributes the stress of the hull generated by the bow's impact as it cleaves the water, it's the place you hang your outboard motor. Determining Your Boat Transom Angle The transom angle - commonly measured in degrees - is the transom's vertical inclination. I mean it is better to be safe than sorry, am I right? The same is true for the newest, high-powered offshore fishing boats, where triple or quadruple motor setups are becoming more and more common. disregard the "hooks" at the front of the The transom is the flat vertical section at the rear of the boat. from the transom. Higher mounting decisions should be left to the professionals. height (that I'm aware of); probably the most common is: maxMicroAmount: 0.0, Workboats, sailboats, and displacement-hulled boats fall into this category.