how to measure transom height for outboard motor

function mpeInit() { manufacturer will recommend the outboard height according to the bracket shape and length. A retired ship captain, Charpentier holds a doctorate in applied ocean science and engineering. Be sure to measure carefully and research thoroughly before diving in. To do so, you will want to measure at the exact center of the transom from the very top to the very bottom. All rights reserved. The engine may be lifted one inch for every eight to ten inches of distance between the transom and the prop, according to a boat riggers rule of thumb. Outboard Motor Shaft Length - LeeRoy's Ramblings Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. Having the cavitation plate a bit lower than the transom is preferable to having it too high. var h = d.getElementsByTagName("head"), Mounting the outboard a little bit lower than the standard point could avoid the possible ventilation and slip on acceleration. and I'll explain it better, (or point you to someone that can help. The dealer just hit you with the long or short shaft question and you have no clue as to what you need or even what he's talking about. Well, raising the outboard motor can be an easy task for you. 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. 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. 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. To do so, take a measurement from the very top to the very bottom of the transom in the precise center. As with anything, there are exceptions to the rule. Increased RPM and additional horsepower feed the need for speed. The boat transom can be flat with zero degree angles. Place the point of a yardstick at the middle of the top of the boat transom. loadScript(ptScript); What the relationship to the pontoons is, I couldn't say. See When St. Peters Basketball Games Are Today! Your at your local outboard dealer shopping for a new motor and the salesman hits you with the question, "short or long shaft?". MarinePartsMan.com also says that V6 bass-boat engines have a 20-inch shaft. s = d.createElement("link"); Your email address will not be published. How to Measure Transom Height For vessels with transom-mounted outboards, you can easily figure out which type of outboard you need to get. Having the cavitation plate too low will cause excess drag and reduced performance at high speeds. Most transom savers can support up to a 150HP motor, which is sufficient for most regular boats. Some may call it a standard length while others may call it a short or a long shaft. Raising an outboard higher on the transom can reduce drag and raise top speed. 4 0 obj A2: Instead of changing to the short outboard shaft, you can try the Jack Plate first. mpeInit(); Adjusting the mounting height of an outboard on the boat transom can affect performance and every boat can be different, so actual on-water testing is best. What Types of Documents Can be Sent to your Kindle Library? This is a measurement that has been used for BassCats, I'm These cookies track visitors across websites and collect information to provide customized ads. The motor length corresponds to the transom height of the boat, measured from the keel to gunwale at the transom. Sailboats use these sometimes, as well as some boaters who want to install a much smaller auxiliary motor to use in case of primary engine failure. Boat transom angles play a pivotal role in the flexibility of the boats trimming abilities. The boat transom can be flat with zero degree angles. Beyond motorboats designed for large outboards, you will see outboards hanging on the sterns of everything from small canoes to large cruising sailboats. clearInterval(interval); A reversetransom that sits too high can impact the propellers of the motor and motor bracket. (Any measurement given as "off the transom" The outboard comes with mounting holes and brackets. Copyright 1999-2023 Boats Group. I hope this helps someone out in their search for a new or newer outboard this season. 12 Small Fishing Boat Accessories to Buy Today. Here we will guide you in how to get the right boat transom height. Whether your on a pontoon boat, fishing boat, or speedboat boating is always one of the best times you can have. displayMicroOffers: false, displayPrimeOffers: true, I live for the weekends when I can go out on the water and escape the stress of life on land. Among them will be first-timers or those who have recently purchased their boats. (function () { Spark Plug 25.0nm(18.4 Ft-lb) (2.55 Kgf-m) Industry standards dictate that for short shaft engines the transom height should be 15. A: The answer varies by boat, but here are some rules of thumb for matching a short shaft outboard to your boat. This alone can outweigh the negatives when deciding to adjust the mount upwards. For slower boats, its less critical to. Bass boats, ski boats, or center cockpit vessels will want to double-check their measurements to get it just right. maxAmount: 6500.0, If it measures anywhere from 17" to around 22", then your going to want to go with a long shaft motor. It is very versatile as it generally . These are vertically aligned so the boater can make adjustments. A long shaft engine requires a height of 20 and extra-long shaft engines will need a transom height of 25. Not to measure boat speed, but to gauge the mounting height of the outboard motor on the boat transom. It also cuts into speed and fuel efficiency. 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. And thats usually the case since the electric outboards are designed with larger and more efficient propeller that needs longer shaft. It can also improve the experience of driving a faster boat. This exhaust port should be about 1 inch above the water line when the boat is idling. Actually there is no designated letter for short shaft. Offshore vessels are often equipped with a large mounting bracket so that the transom can be left at full height. % The transom in a boat today is a place to hang your outboard motor. If your boats transom height is 15-16, a short shaft engine is required, and if it is 20-21, a long shaft engine is required. To achieve 35 mph with a 6 hp engine, the total weight is 135 lbs (boat motor fuel passengers). His works have appeared in regional newspapers in North Dakota and in "North Dakota Horizons" and "Cowboys and Indians" magazines. It varies between different motors and boats. Where Onboard a Boat is the Transom Located and More About Transom Heights A propeller operates based on the height of the transom. Wherever the outboard clamping bracket is, use this as the basis for measurement. (616) 364-0666, On all contiguous US part orders over $100. Say the 20 shaft is a long shaft length for gas engines, but it is a short shaft length for electric outboard motors. In the second photo, we've measure down from the top of the Detwiler With the long side (22 1/2), place a carpenters square ) in opposition to the keel. Of course, its always best to go with standard practices when choosing thebest boat engine. the aluminum plate on top of the transom), to the bottom of the motor This placement is not only recommended but it will give you the best performance compared to something that is too long or too short. 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. There Theyre also useful if the back of your boat has a non-standard measurement. You also might not be able to lift the outboard out of the water entirely for storage. Tightening Torque for Engine. Determining Your Boat Transom Angle The transom angle - commonly measured in degrees - is the transom's vertical inclination. would be more accurate.) In the case of a dinghy or johnboat, this point may be the top of the transom. Boats with more engine power and weight require longer shaft outboards for better balance. *The Factors indicates the adjustment affected by on your boat type, the outboard working environment, and the transom distance as discussed above. Whats the best height for my boat motor? mpeSelector: ".pt-mpe", This is handy if youre shopping for second-hand outboards or looking to sell the one that came with your boat. Doing this can have adverse effects. Happy boating! You can use a longer shaft than recommended and your boat will work fine. This will be the 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. If it measures 15" or with in a inch of that you will need a short shaft outboard. measuring; you may have to "extend" the flat part of the Here is a picture that shows you exactly where the outboard motor shaft length stands: Usually the shaft length for outboard motors falls into the following 4 sizes: In practice, you may find the outboard motor shaft length varies among different brands and manufacturers like the Honda,Suzuki, Yamaha, Torqeedo, etc. function loadScript(script) { As a dealer I don't really like hearing this because there is a chance it could go either way and you have to get it right. Here we will guide you in how to get the right boat transom height. primeApr: 12.99, Plus, a low transom cut is an invitation for the water to flood the boat. former editor at Boating Magazine and contributor to many national publications Small portable outboards ranging from 2 to 20 horsepower are usually sold only in short or long shaft versions. priceSelector: ".price--withoutTax, span.price.price--withTax", To break it down a bit more for you: Short shafts are 15-inches long. It doesnt matter if you have a fiberglass boat, bay boat, big or small boat. With some boats I have a pretty good idea as to what length motor should be hung on them. How to Choose Between a Motor Tote and Transom Saver to Support an If your outboard motor height. It is extremely important that the boater understands the significance of the transoms height. However, there may be times when a boater strays away from these recommendations. The height is approximately six inches higher than with a propeller. bracket. brackets. LOYALHEARTDY Outboard Motor 6 HP 2-Stroke Inflatable Fishing Boat 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. (1) Multiply the overall length of your boat (in feet) by it's widest beam at the stern (excluding any Fins and or Shear) (2) Locate that value on the left hand vertical column of the chart below. straight edge from the center of the pad, but this time you're measuring Measuring Motor Height - BassBoat Central Check out some hot FAQs to help you get the proper outboard shaft lengths. An inch or two probably wont make a big difference, but any more than that will lead to trouble. Boaters who consider going with a higher mount can see increased speeds. It is unsafe to have the engine block too close to the water on a low transom. This is somewhat similar to #2, in that you are again measuring with a 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 same is true for the newest, high-powered offshore fishing boats, where triple or quadruple motor setups are becoming more and more common. All rights reserved. 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. For vessels with transom-mounted outboards, you can easily figure out which type of outboard you need to get. var addyd53b59933f6c3f2e8b59f1b4a6d41fa5 = 'info' + '@'; This is also known as the shaft length. When trimming your motor, they provide you a greater bow response. Hold the tape on the top, center of the taffrail and measure straight down to the point, usually a sharp angle, where the transom joins the bottom of the boat. (updated Other factors to consider when determining the mounting height of an outboard are related to performance. Read the measurement on the transoms bottom. If it measures anywhere from 17" to around 22", then your going to want to go with a long shaft motor. Charles Plueddeman is Boats.com's outboard, trailer, and PWC expert. e-mail These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. 2019s List of the Best Recreational Pontoon Boats for Sale. Or measure from the main engine prop up to the water line? ensure that your measurement is accurate. straight edge on the top of the transom to "extend" it out Set the end of the tape on the outside edge of the taffrail at the center and measure inward to the inside edge of the taffrail. bracket forward with a straight edge to where you can then measure up How do you measure a transom on an outboard motor? 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. Engine Oil Type Genuine or Recommended 2str Engine Oil. Boat hulls are designed in three basic types that range from slow displacement and semi-displacement hulls to the fastest planing hulls. One of the main concerns is causing the engine to overheat if not enough water reaches the engine to keep it cool. On most newer center consoles and offshoreboat transoms might include a rear door leading to a swim platform as well as a molded setback bracket. The transom is the back of the boat where the motor is hung. Doing this can have adverse effects. Other boats that need long shafts are. Place the rulers end on the ground behind the club and let the club to rest on top of it. While this is the case there is certain saltwater motors that are extra extra long at 30 and 35 shaft. Any questions? Smaller inflatables and dinghies needshort shaft motors, whilst bigger boats require long or, in some circumstances, extreme long shaft versions. Buying a boat can be an exciting purchase. If your boat is newer and the manufacturer is still in business, you might also want to try to give them a call. endobj Basically, there are three main ways to measure motor The propellers will also have trouble reaching the water. This distance is very important to the performance of you boat. Motor height on pontoon? | Boating Forum - iboats Boating Forums All you need to do is measure how much to rise. This provides seaworthiness and offers maximum protection from large seas. With it comes a lot of responsibility and new things to learn includingboat maintenanceand boat basics. It doesnt matter if you have a fiberglass boat, bay boat, big or small boat. 5/rC,aQhsK@Q. It moves an outboard up and down to optimize performance and enable a boat to venture into shallower water than it might otherwise. Typical motor lengths include the following. Outboard motors can be fitted to a variety of boats, so manufacturers have standardized their engines to go on virtually anything. Brackets are also handy for boats that do not have flat transoms, like canoe-stern sailboats or fan-tailed motor vessels. Mounting kicker motor - General Discussion Forum | In-Depth Outdoors So from there, I will try to help out by asking questions about your boat such as what type it is and the length. The cookies is used to store the user consent for the cookies in the category "Necessary". What are Apple Podcasts Subscriptions and Channels? If you are running a slower boat, the exact location of the ventilation plate is less important. 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. 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. The boater must also consider if the boat transomsupport is designed to bear the weight of a higher mount. I also love helping others, which is why I created this website. Trimming in, trimming down, and trimming out are all terms that a beginning boater should learn. With a motor tote, the outboard and boat move as one, independently of the trailer, so there are no concerns about the boat shifting on the trailer, he says. Although the longer outboard shaft length can lead to lower speed and more drag, the boat can push a heavier load. Small motors built for sailboats might come in a unique configuration with an extremely long shaft since these are mounted higher off the water. The motor is what powers the boat so the two go hand-in-hand. However, there may be times when a boater strays away from these recommendations. When you measure the width of the stern, mark the center with a grease pencil. Boat Transom Heights - The Beginner's Guide | My Westshore But opting out of some of these cookies may affect your browsing experience. Also, how do you determine the length of an outboard transom? For boats equipped with a bracket, calculate the same measurement but based on the bracket and not the transom. All things considered, sticking with the industry standard is best for the beginner. Youll need a short shaft outboard if its 15 or less than an inch shorter. Figuring out how to measure motor height on a Among them will be first-timers or those who have recently purchased their boats. Use the mounting bracket on the motor to know where it will sit on the boat. var ptScript = "https://cdn.paytomorrow.com/js/pt-mpe.min.js"; If it measures between 17 and 22, youll want to go with a long shaft motor. Workboats, sailboats, and displacement-hulled boats fall into this category. As a result, the issue is whether my boat need a short shaft or long shaft motor. window.dataLayer = window.dataLayer || []; A: Any boat that has a 21 to 27 inch aft transom will need an extra long shaft outboard. And the rule of thumb is that you should keep the cavitation plate level with the bottom or keel of the boat. How high exactly do you have to raise the transom?-. C Cheaptoon Cadet Joined Aug 4, 2010 Messages 28 Aug 24, 2010 #4 Re: Motor height on pontoon? a Detwiler manual jackplate. bassboat can be a bit confusing at times; hopefully this will help sort Outboard Motor Shaft Length: How do I measure? This cookie is set by GDPR Cookie Consent plugin. Industry transom height standards have been evolved during the last 30 years: 15 for short shaft engines, 20 for long shaft engines, and 25 for extra-long shaft engines. You dont have to be a mathematician to determine the correct boat transom angle. d.addEventListener("DOMContentLoaded", function (e) { Safely but briskly accelerate. 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. s = d.createElement("script"); 7. How high exactly do you have to raise the transom?- - Outboard Jets endobj Smaller boats may use adjustable jack plates that can be changed to fit any outboard. Some fishing boats can handle the motor being underwater. The brackets can add 1 inch to the overall mounting height of the outboard. For over five years he has worked as a newspaper reporter and historic researcher. The vertical distance between the interior of the clamp and the cavitation plate is the shaft length specified by the outboard manufacturer. To measure the transom height, measure from the center on for transom (rear of the boat). Boats that use longer outboard shafts include: Over time, Boating Hub has grown into a resource for boating enthusiasts around world. Kicker Motor Shaft Length - This Old Boat - Lake Ontario United - Lake Proper Mounting Height for an Outboard - Gone Outdoors This measurement is primarily designed for single motor propulsion. The form of a boats transom varies depending on the manufacturer and model. Boats with extended transoms, brackets that extend the mounting bracket for the outboard motor behind the back of the boat, can use a higher outboard height. The mounting height of an outboard motor can impact the speed and handling characteristics of the boat. The transom is the flat vertical section at the rear of the boat. Allowing the propeller to pull water from underneath and push it out behind the boat. This cookie is set by GDPR Cookie Consent plugin. This alone can outweigh the negatives when deciding to adjust the mount upwards. Outboards designed for saltwater applications usually have longer shafts. Owners of bass boats, RIBs, or offshore fishing boats need to get this right. minAmount: 300.0, To achieve this, the motor itself has to be attached at the correct height. This cookie is set by GDPR Cookie Consent plugin. Many single-engine boats mount a smaller auxiliary motor for emergency use. Outboard shaft length plays a crucial role in the performance of your boat. <>/Metadata 127 0 R/ViewerPreferences 128 0 R>> 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. How the outboard will sit on the back of the boat depends on how the transom is designed. Using your existing control box and gauges will save you quite a bit of money in the end. The height of the boat transom dictates the size of the outboard motor. Extra-long shafts are 25-inches long. 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. The transom is the flat vertical section at the rear of the boat. #2. To do so, measure from the stern (back) of the boat to the midpoint of the hull on both sides. The Best Way to Measure Prop to Pad | How to measure Outboard Motor Height 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. So you should just measure the height of the boat's transom from the center down to the lowest point of the hull, and compare transom height with the outboard shaft length numbers. |. 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. All boats are different, and the motor manufacturers produce a variety of standard lengths. Oftentimes you will want to adjust the outboard shaft length in order to improve the boat performance such as speed. So if you are measuring the outboard shaft length for the powerboat, planing boat, or any boat for which the speed is the priority, take the outboard shaft length 1 to 1.5 (depending on your boat types) shorter than standard would be better. h[0].appendChild(s); Mounting the motor lower on the boat transom can create excessive spray, increase case drag, reduce underwater clearance, and negatively impact faster boats.