August 9/08). C Cheaptoon Cadet Joined Aug 4, 2010 Messages 28 Aug 24, 2010 #4 Re: Motor height on pontoon? It is where the outboard is mounted, and some boat owners place the name of the boat. And thats usually the case since the electric outboards are designed with larger and more efficient propeller that needs longer shaft. Keep these numbers in mind if you ever have a need for a new outboard motor for your boat. With it comes a lot of responsibility and new things to learn includingboat maintenanceand boat basics. (Putting a Mounting the motor lower on the boat transom can create excessive spray, increase case drag, reduce underwater clearance, and negatively impact faster boats. displayMicroOffers: false, Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. var addy_textd53b59933f6c3f2e8b59f1b4a6d41fa5 = 'info' + '@' + 'vanssports' + '.' + 'com';document.getElementById('cloakd53b59933f6c3f2e8b59f1b4a6d41fa5').innerHTML += ''+addy_textd53b59933f6c3f2e8b59f1b4a6d41fa5+'<\/a>'; Higher mounting decisions should be left to the professionals. Beefier jack plates can be fitted should a boater be looking to mount an outboard with a shorter shaft than their transom demands. The amount of degrees the transom leans back from vertical is known as the transom angle. bracket forward with a straight edge to where you can then measure up Upstream Securitys Disruptive Telematics Technology, The challenges of scaling a cloud-based security system, OneStreams unified platform streamlines financial data management, OneStreams impact on the financial software market. When the jet drive is on the motor, set the height so that the leading edge of the intake is flush with the boat bottom. maxTerm: 36, Triton. All things considered, sticking with the industry standard is best for the beginner. } This measurement was approximately 4". However, there may be times when a boater strays away from these recommendations. A big NO. You Save my name, email, and website in this browser for the next time I comment. The transom is the back of the boat where the motor is hung. Knowing the width, height and depth of your transom allows you to make several important decisions when selecting or purchasing a new outboard. It can also improve the experience of driving a faster boat. I also love helping others, which is why I created this website. To measure the transom height, measure from the center on for transom (rear of the boat). maxMicroAmount: 0.0, Then, you can pick the right engine. Variables to consider when determining the mounting height include the size and style of the boat and the length of the outboard motor's shaft. The distance between the ends of a transom is measured in inches. The average transom angle is around 14 degrees. h[0].appendChild(s); This is measured by the propeller shaft being parallel to the vessels bottom. This is a measurement that has been used for BassCats, I'm As summer approaches there will be more boaters taking to the water. s = d.createElement("link"); All rights reserved. :$I>M W$h"%U_yzIb?]NHg_G|r@nX eTf."SQ Increased RPM and additional horsepower feed the need for speed. In the past, though, it housed the officers and captain of 17th, 18th and 19th century sailing ships. To achieve this, the motor itself has to be attached at the correct height. gtag('config', 'G-QX0Y76NH40'); Whether your on a pontoon boat, fishing boat, or speedboat boating is always one of the best times you can have. Higher mounting decisions should be left to the professionals. Some may call it a standard length while others may call it a short or a long shaft. since 1986. In lower mounting, the engine is set lower than the recommended standard. Analytical cookies are used to understand how visitors interact with the website. Step 3: Add another 10 cm (4'') to the previous calculation for the final ideal shaft length. Boat transom angles play a pivotal role in the flexibility of the boats trimming abilities. Having the cavitation plate a bit lower than the transom is preferable to having it too high. 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. A hydrofoil will typically level off the ride by driving the stern up and the bow down, and will stop or considerably minimize porposing on a 16 footer with a mid-sized outboard and no tabs, for example. Another important measurement is the transom angle. your motor will be higher.) To make the yard stick long enough to measure the length of all the clubs, tape the ruler to the top. Add yours in the comment and Ill get back to you asap. Then test the boat and adjust the height, if necessary . To do so, you will want to measure at the exact center of the transom from the very top to the very bottom. If the propeller fails to ventilate, the motor is mounted to low. MarinePartsMan.com also says that V6 bass-boat engines have a 20-inch shaft. 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. The brackets can add 1 inch to the overall mounting height of the outboard. The boater must also consider if the boat transom support is designed to bear the weight of a higher mount. Where Onboard a Boat is the Transom Located and More About Transom Heights A propeller operates based on the height of the transom. This will be the But, how do you measure it? There is a simple test to see if your outboard motor is set at the best height. (function () { It is extremely important that the boater understands the significance of the transoms height. It is where the outboard is mounted, and some boat owners place the name of the boat. As you can see, the measurement is about 2 1/2". 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. Step 4. A: The answer varies by boat, but here are some rules of thumb for matching a short shaft outboard to your boat. Take your time and understand your boat and your entire transom. In addition, motor totes will not harm the finish of the lower unit. We also use third-party cookies that help us analyze and understand how you use this website. 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. This allows the engine to idle without the flow of the exhaust being restricted. mpeInit(); You dont have to be a mathematician to determine the correct boat transomangle. %PDF-1.7 Other factors to consider when determining the mounting height of an outboard are related to performance. Measure from the top of the transom to the bottom of the hull. height (that I'm aware of); probably the most common is: Offshore vessels are often equipped with a large mounting bracket so that the transom can be left at full height. Industry standards dictate that for short shaft engines the transom height should be 15. Here we will guide you in how to get the right boat transom height. The boater must also consider if the boat transomsupport is designed to bear the weight of a higher mount. var interval = setInterval(function () { All you need to do is measure how much to rise. Rest the yard stick or another suitable straight edge along the keel on the bottom of the boat so that it makes a straight line aft to the outboard. With a jack plate, you can mount it exactly where you want it. MPW eBay Store - Thousands of New OEM Old Stock Parts! (3) Move horizontally across the chart until you hit the graph curve. Also, the boat will be more likely to hit bottom or submerge objects such as rocks or logs. Re: Dinghy with a long shaft motor? Whether your on a pontoon boat, fishing boat, or speedboat boating is always one of the best times you can have. When you measure the width of the stern, mark the center with a grease pencil. Simply start with the engine in idle, followed by, If you decide to make some custom adjustments we have the. Measure the area of the transom directly where the engine will be mounted. The boat transom height is measured from the lowest point on the keel along the center line to the spot where the outboard motor's mounting holes bracket rests. Happy boating! In the case of a dinghy or johnboat, this point may be the top of the transom. Transom Outboard Engine Position - YouTube 0:00 / 0:56 Transom Outboard Engine Position BOATING SCENE 763 subscribers 609 211K views 5 years ago www.boatingscene.com.au Sometimes when your. This measurement is primarily designed for single motor propulsion. Youll need a short shaft outboard if its 15 or less than an inch shorter. If it measures anywhere from 17" to around 22", then your going to want to go with a long shaft motor. Many single-engine boats mount a smaller auxiliary motor for emergency use. The performance of these boats depends on quite a lot of factors, but getting the outboard length just right is an essential first step. This email address is being protected from spambots. If it measures 15" or with in a inch of that you will need a short shaft outboard. var prefix = 'ma' + 'il' + 'to'; So its easier and safer to communicate with the dealer with the exact measurement of outboard shaft length in order to get the right model. Always weigh the risks of making adjustments. This transom saver will support the weight of your outboard throughout your road travel, steadily bracing it against the trailer frame to relieve your transom of the weight and impact from consistent bouncing. Copyright 1999-2023 Boats Group. It also cuts into speed and fuel efficiency. Plus, a low transom cut is an invitation for the water to flood the boat. A retired ship captain, Charpentier holds a doctorate in applied ocean science and engineering. Should I take the raft onto the water and measure the exact distance from the top of the transom to the water line? 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. If it measures between 17 and 22, you'll want to go with a long shaft motor. The transom is the flat vertical section at the rear of the boat. endobj A reversetransom that sits too high can impact the propellers of the motor and motor bracket. So how to determine the outboard shaft length? In the second photo, we've measure down from the top of the Detwiler What are Apple Podcasts Subscriptions and Channels? 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. The mounting height of the outboard engine is the equivalent of the distance between the base of the motor and the top of the propeller. See When St. Peters Basketball Games Are Today! A long shaft engine requires a height of 20 and extra-long shaft engines will need a transom height of 25. Of course, its always best to go with standard practices when choosing thebest boat engine. A transom saver, which can change the spacing between the lower unit and the trailer, negates some of the support. In extremes, the engine can have overheating problems if the boat is raised to a point where the water inlets for the cooling system are out of the water. Using your existing control box and gauges will save you quite a bit of money in the end. will be to the flat part; if you measure to the bottom of the brackets With such an important, long-term, and expensive upgrade, its never a bad idea to double-check. So if you are measuring the outboard shaft length for smaller boats, inflatables, dinghies, sailboat or other low-speed work boats, the cavitation plate is often about 2 below the bottom. This restriction includes most fishing boats and longer sailboats. var ptScript = "https://cdn.paytomorrow.com/js/pt-mpe.min.js"; The faster your boat, the more critical it is to get the sizing just right. If possible for your peace of mind and not let down that magnificent purchase opportunity, place that 08 kicker at back transom and test for yourself. Because of the increased friction, cavitation reduces efficiency. If youd like to see this in video format, skip to 0:44 in the below YouTube Video: Is it OK to put a long shaft outboard on a boat thats rated for a short shaft? Here we look at the effects of standard, lower and higher mounting. When mounting the engine, you want the cavitation plate to be 1 above the boat bottom for every 12 away from the transom. Since the ventilation plate & foil are burried under water it is obviously too low. If you have a small boat with a 15 to 17 inch aft transom, youll most likely need a short shaft outboard. (updated Propshaft in x\[D~OUCO6[j](l%ay <8cylY{.L2s#]~U6A|Wj]-oo|mubqY6wbY_|!>Z8(RB:RHeTzOGO_=~t\ The form of a boats transom varies depending on the manufacturer and model. In step 3, add another 10 cm (4") to the previous calculation in order to develop the ideal shaft length. I believe 20 to 21 inches is the optimum length for a lengthy shaft. Your email address will not be published. This cookie is set by GDPR Cookie Consent plugin. | Sitemap, The Marine Parts Warehouse Outboard Museum, OBR Powerhead / Shortblock Warranty Claim Form, Remanufactured vs. No one wants to have issues with a new transom or boat repairs. resting on the transom if you had the motor all the way down on the boat The anti-cavitation plate above the prop needs to be within an inch of the bottom of the transom, therefore, the prop should be well below the transom. One of the great things about an outboard motor is how versatile it is. Before we get started lets see what a boat transom is and what it does. Boats with more engine power and weight require longer shaft outboards for better balance. How the outboard will sit on the back of the boat depends on how the transom is designed. Use the mounting bracket on the motor to know where it will sit on 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. debugMode: false, of the "bullet" on your lower unit. However, the shaft length for smaller boats could be long or short depending on its style, speed requirement, etc. Gear case sits just below or at the hull depth due to the deep v. Place the point of a yardstick at the middle of the top of the boat transom. You also have the option to opt-out of these cookies. 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. ), Al Shields With the motor trimmed so that the propshaft is parallel to the keel, the anti-ventilation plate should be just about even with your straight edge, and thus even with the boat bottom at the keel. To break it down a bit more for you: Short shafts are 15-inches long. Your email address will not be published. A yardstick will help you determine if your outboard engine is at the right height. Like Westshore Marine & Leisure on Facebook! It was a 23-foot Crestliner Grand Cayman pontoon boat.
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