Transom Outboard Engine Position - YouTube We also use third-party cookies that help us analyze and understand how you use this website. His works have appeared in regional newspapers in North Dakota and in "North Dakota Horizons" and "Cowboys and Indians" magazines. e-mail They keep water out of your prop and increase water pressure in the system. As mentioned above, the operation of the propeller relies on the transom height. Repowering your boat is one of the most expensive upgrades you can make. My family and I used it to fish, ski (yes, you can ski behind a pontoon boat), and cruise the lakes near our home. Extra-extra long shafts are 30-inches long. One of the main concerns is causing the engine to overheat if not enough water reaches the engine to keep it cool. Industry standards dictate that for short shaft engines the transom height should be 15. One of the factors in determining the height of the outboard is the placement of the exhaust port on the lower unit of the outboard engine. Some outboards have a serial number that tells you which shaft length to go for. A long shaft engine requires a height of 20 and extra-long shaft engines will need a transom height of 25. The amount of degrees the transom leans back from vertical is known as the transom angle. For example, you can have the Mercury outboard shaft length by model code. The motor is what powers the boat so the two go hand-in-hand. hulls, such as Allisons, Bullets, Strokers, etc., this measurement could According to MarinePartsMan.com, the outboard can be raised 1 inch above the standard height for every 10 miles per hour of speed the boat can attain. Higher mounting decisions should be left to the professionals. Step 4. var addyd53b59933f6c3f2e8b59f1b4a6d41fa5 = 'info' + '@'; Simply start with the engine in idle, followed bytrimming the motor out by one-half to full trim. Spark Plug 25.0nm(18.4 Ft-lb) (2.55 Kgf-m) Most of the time, adding a hydrofoil to an outboard improves performance. The point where these measurements intersect is your centerline. parallel with the straight edge. Boaters who consider going with a higher mount can see increased speeds. How Transom Height Is Measured var path = 'hr' + 'ef' + '='; Gear case sits just below or at the hull depth due to the deep v. It is where the outboard is mounted, and some boat owners place the name of the boat. Outboard Motor Shaft Length - LeeRoy's Ramblings (3) Move horizontally across the chart until you hit the graph curve. To do so, measure from the stern (back) of the boat to the midpoint of the hull on both sides. Displacement hulled vessels like sailboats and workboats can benefit from a little more space between the hull and cavitation plate, but not much. Setting Height of Outboard Motor - YouTube bracket. 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. Outboard motors can be fitted to a variety of boats, so manufacturers have standardized their engines to go on virtually anything. mpeSelector: ".pt-mpe", Youll also want to pay attention when youre in shallow water because your prop will be lower than normal. Beyond motorboats designed for large outboards, you will see outboards hanging on the sterns of everything from small canoes to large cruising sailboats. Top 10 Choices for Boaters, Mercury Introduces 600HP V12 Verado Outboard Engine, The Outboard Expert: Tohatsu Propane Outboard Engine. Having the cavitation plate a bit lower than the transom is preferable to having it too high. Safely but briskly accelerate. For vessels with transom-mounted outboards, you can easily figure out which type of outboard you need to get. AztH ^zv_ cT,E1K/rAB54| Your at your local outboard dealer shopping for a new motor and the salesman hits you with the question, "short or long shaft?". Always weigh the risks of making adjustments. 2019s List of the Best Recreational Pontoon Boats for Sale. If it measures 15" or with in a inch of that you will need a short shaft outboard. s.setAttribute("rel", "stylesheet"); Look at the part of your motor that would be (function () { } Copyright 1999-2023 Boats Group. How do you measure a transom on an outboard motor? Measure straight down to the lowest point on the hull. How Low Should a Motor Set on a Pontoon Boat? (Explained) The transom is the boats flat vertical part at the back. function gtag(){dataLayer.push(arguments);} Mounting the motor lower on the boat transomcan createexcessive spray, increase case drag, reduce underwater clearance, and negatively impact faster boats. This is the dimension you'll need when selecting a width for your outboard motor's mounting bracket. The height of the transom is estimated by using the center line to measure from the bottom of the hull to the top of the transom. What is a Transom Saver And Do I Need One? - Boat Safe A transom saver, which can change the spacing between the lower unit and the trailer, negates some of the support. Outboard shaft length plays a crucial role in the performance of your boat. brackets. However, there may be times when a boater strays away from these recommendations. Depending on the manufacturer, size names might change. Increased RPM and additional horsepower feed the need for speed. Industry standards dictate that for short shaft engines the transom height should be 15. This is probably the worst case scenario out of the two. Save my name, email, and website in this browser for the next time I comment. Increased RPM and additional horsepower feed the need for speed. How to Measure Transom Height For vessels with transom-mounted outboards, you can easily figure out which type of outboard you need to get. 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. trimming the motor out by one-half to full trim. If it measures between 17 and 22, you'll want to go with a long shaft motor. How to Raise Outboard Motor on Transom? - Raising the Outboard Motor When the right length motor is hung on the transom of a boat, the cavitation plate (the large plate that extends out over the propeller) should be even with the very bottom of the boat. If you have already measured you transom tip to bottom to be 20", then if you place aux sdieways to central engine your available transom height will be probably 1"-1.5" " higher and work perfecty. ), Al Shields It also decreases the boats lift and increases the time it takes for the boat to reach plane. Generally, the anti-ventilation plate on most engines is aligned with the bottom of the vessel. As a dealer I run into this situation from time to time, which is fine but getting the right length outboard for your boat is crucial. The general guideline for longer shaft outboards is that the transom height should be at least 20 inches (50,8cm) above the waterline. 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. endobj Whether you already own a boat or looking for your first watercraft we are here to service your needs. The height of the transom is calculated by measuring from the bottom of the hull to the top of the transom, using the center line. will be to the flat part; if you measure to the bottom of the brackets disregard the "hooks" at the front of the Tightening Torque for Engine. Most of the standard engined boats it takes shafts that are 15-30inches long. https://www.bornagainboating.com/Get Your Born Again Boating Clothing! The height of the boat transom dictates the size of the outboard motor. jackplate to a point level with the top of the transom. And the rule of thumb is that you should keep the cavitation plate level with the bottom or keel of the boat. While this is the case there is certain saltwater motors that are extra extra long at 30. It also includes attaching the right engine. Boat Transom Heights The Beginners Guide, Buying a boat can be an exciting purchase. not sure that it's still used. and I'll explain it better, (or point you to someone that can help. enableMoreInfoLink: true, It does not store any personal data. Each one has a totally different effect on the boats performance. When mounting the engine, you want the cavitation plate to be 1 above the boat bottom for every 12 away from the transom. measuring; you may have to "extend" the flat part of the You can use a longer shaft than recommended and your boat will work fine. Your email address will not be published. window.dataLayer = window.dataLayer || []; Basically, there are three main ways to measure motor height (that I'm aware of); probably the most common is: # 1: Height of the motor off the transom This is simply a measurement taken from the top of the transom (top of the aluminum plate on top of the transom), to the bottom of the motor "brackets". Measuring the shaft length can be done in various ways, but the most common way is by using a tape measure. The same is true for the newest, high-powered offshore fishing boats, where triple or quadruple motor setups are becoming more and more common. Knowing how this can affect the overall operation of the boat is a factor to be considered. The transom is the flat vertical section at the rear of the boat. actually have the propshaft above the pad.). To make the yard stick long enough to measure the length of all the clubs, tape the ruler to the top. ), and place it on the bottom of the pad in the center. To do so, take a measurement from the very top to the very bottom of the transom in the precise center. What Types of Documents Can be Sent to your Kindle Library? Figuring out how to measure motor height on a If you go too short your more than likely going to cavitate and loose power. The engine must be linked to the transom at the proper height for a propeller to best meet specific boating demands. It will ensure that the outboards trim will be effective, and it will save you gas too. "brackets". Amazon has plate extensions to allow adjustments without buying a new motor: T-H Marine Jack Plate Extension. This is measured by the propeller shaft being parallel to the vessels bottom. Cavitation is when the propeller is out of the water due to the boat forming a wake of "air bubbles" or "vapor cavities" around the prop. stream var h = d.getElementsByTagName("head"), If it measures 15" or with in a inch of that you will need a short shaft outboard. manufacturer will recommend the outboard height according to the bracket shape and length. Determining Your Boat Transom Angle The transom angle - commonly measured in degrees - is the transom's vertical inclination. But, how do you measure it? Here we will guide you in how to get the right boat transom height. Doing this can have adverse effects. Take the center measurement from the top to the bottom of the hull. I run a 9.9 Mercury Bigfoot 20" shaft off the swim platform of my 89 Trophy 2160. Place the rulers end on the ground behind the club and let the club to rest on top of it. Step 2: After you get the transom height, add the radius of the propeller (check the user manual, and then technical drawing for the number) to calculate the minimum shaft length needed to make it work. mpeInit(); Eq*^?6R83e+j}UY.(M7k]~4g)g ~wmS{ O7t/o(W|X? Ten years ago I bought my first boat. Disclaimer: As an affiliate I may earn a commission on any qualifying purchases, including those from Amazon.com, at no extra cost to you read more. On the downside, a higher mount can interfere with the boaters steering capabilities. PayTomorrow.mpeInit({ Charles Plueddeman is Boats.com's outboard, trailer, and PWC expert. Get the latest updates on new products and upcoming sales, 2023 Marine Parts Warehouse Incorporated document.getElementById('cloakd53b59933f6c3f2e8b59f1b4a6d41fa5').innerHTML = ''; height (that I'm aware of); probably the most common is: As summer approaches there will be more boaters taking to the water. The clamp bracket is designed so that the engine's mounting height on the transom can be adjusted higher than standard. As you can see, the measurement is about 2 1/2". <> The transom is the rear wall of the boat where the outboard engine is mounted in the middle.