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. Boat hulls are designed in three basic types that range from slow displacement and semi-displacement hulls to the fastest planing hulls. height (that I'm aware of); probably the most common is: Some may call it a standard length while others may call it a short or a long shaft. If your boat is newer and the manufacturer is still in business, you might also want to try to give them a call. 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. maxAmount: 6500.0, Pretty easy to figure out but like I said its crucial to pairing a motor with a boat. Typical motor lengths include the following. 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. It can also improve the experience of driving a faster boat. 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. How to Measure Transom Height For vessels with transom-mounted outboards, you can easily figure out which type of outboard you need to get. This illustration depicts four different outboard mounting height options (courtesy Mercury Marine). Step 3: Add another 10 cm (4'') to the previous calculation for the final ideal shaft length. On the downside, a higher mount can interfere with the boaters steering capabilities. %PDF-1.7 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. 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. All boats are different, and the motor manufacturers produce a variety of standard lengths. will be to the flat part; if you measure to the bottom of the brackets Before we get started lets see what a boat transom is and what it does. Look at the part of your motor that would be window.dataLayer = window.dataLayer || []; When fighting waves from the stern, a 20-inch transom is considerably safer. #2. You may wonder how deep your prop should be in the water. Since the ventilation plate & foil are burried under water it is obviously too low. There are 2 steps to help get a relatively accurate figure. But opting out of some of these cookies may affect your browsing experience. Rebuilt - What You Need to Know, Lower Unit and Sterndrive Break-In Instructions. Extra-extra long shafts are 30-inches long. s.setAttribute("rel", "stylesheet"); This cookie is set by GDPR Cookie Consent plugin. Determining Your Boat Transom Angle The transom angle - commonly measured in degrees - is the transom's vertical inclination. 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. The cookie is used to store the user consent for the cookies in the category "Analytics". Measure the area of the transom directly where the engine will be mounted. clearInterval(interval); var xmlHttp = new XMLHttpRequest(); It also cuts into speed and fuel efficiency. of the motor off the transom This will be the Top 10 Choices for Boaters, Mercury Introduces 600HP V12 Verado Outboard Engine, The Outboard Expert: Tohatsu Propane Outboard Engine. Take your time and understand your boat and your entire transom. Place the bracket on the transom to the left of the main outboard or rudder. This is somewhat similar to #2, in that you are again measuring with a Is my outboard long or short shaft? Beginning boaters should be aware of the boats measurements. It was a 23-foot Crestliner Grand Cayman pontoon boat. While this is the case there is certain saltwater motors that are extra extra long at 30. This is simply a measurement taken from the top of the transom (top of Or it can have an angle degree as high as 30. the aluminum plate on top of the transom), to the bottom of the motor I would ask you to go back and measure the transom of your boat. Setting Height of Outboard Motor - YouTube 0:00 / 0:46 Setting Height of Outboard Motor nates90 71 subscribers Subscribe 83 Share 63K views 7 years ago #boatservice #outboardmotor. The propellers will also have trouble reaching the water. It is extremely important that the boater understands the significance of the transom's height. 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. 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. However, the shaft length for smaller boats could be long or short depending on its style, speed requirement, etc. To achieve this, the motor itself has to be attached at the correct height. Since the length of the shaft of your outboard is associated with the size boat, smaller engines will generally have shorter shafts. Your goal is to measure how the outboard will sit, so start from the clamping plate and follow the centerline of the hull. 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. Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. However, your boat will have slightly more drag which will reduce your maximum speed. There are also specialty motor shaft lengths. In the past, though, it housed the officers and captain of 17th, 18th and 19th century sailing ships. (3) Move horizontally across the chart until you hit the graph curve. Brackets are also handy for boats that do not have flat transoms, like canoe-stern sailboats or fan-tailed motor vessels. Here we look at the effects of standard, lower and higher mounting. How do you measure a transom on an outboard motor? x\[D~OUCO6[j](l%ay <8cylY{.L2s#]~U6A|Wj]-oo|mubqY6wbY_|!>Z8(RB:RHeTzOGO_=~t\ Other boats that need long shafts are. Boats that use longer outboard shafts include: Add the two measurements and you get 6 1/2". Follow Westshore Marine & Leisure on Wordpress! Keep these numbers in mind if you ever have a need for a new outboard motor for your boat. 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. function mpeInit() { 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. You reply, "Im not sure, I think its a long". The pros and cons of properly . Later in the article is an image that shows you exactly where to measure. The standard shaft length for most outboard engines less than 125 horsepower is 20 inches. Add yours in the comment and Ill get back to you asap. The cookie is used to store the user consent for the cookies in the category "Other. You dont have to be a mathematician to determine the correct boat transomangle. If you have a question or need additional information. Also, the boat will be more likely to hit bottom or submerge objects such as rocks or logs. Other boats that need short shafts are: A: If you have a small boat with a 18 to 21 inch aft transom, youll most likely need a long shaft outboard. So how to determine the outboard shaft length? The form of a boats transom varies depending on the manufacturer and model. 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. It will ensure that the outboards trim will be effective, and it will save you gas too. Mounting the motor lower on the boat transomcan createexcessive spray, increase case drag, reduce underwater clearance, and negatively impact faster boats. Step 2 requires the propeller's radius (check the user manual and then the technical drawing). % So how to measure outboard shaft length? The boat transom can be flat with zero degree angles. What Types of Documents Can be Sent to your Kindle Library? If you have an outboard motor, the distance from one end to another will be found on the side or on a label near its bottom. Many boat transoms are modified to use a different length of outboard by using a bracket. These two measurements will give you the length of the shaft you need. If it measures 15" or with in a inch of that you will need a short shaft outboard. Learn More About Your Boats Systems By Joining The Born Again Boating Academy! motor brackets a Detwiler manual jackplate. No one wants to have issues with a new transom or boat repairs. Other factors to consider when determining the mounting height of an outboard are related to performance. A retired ship captain, Charpentier holds a doctorate in applied ocean science and engineering. Attention: Remember to measure the outboard shaft length straight up and down instead of measuring along the transom. Cavitation plates are used on the bottom components of boats to help them operate better. Thats a fairly simple list of symptoms, but if your motor is too low, youll probably notice at least one of them. The transom in a boat today is a place to hang your outboard motor. Check out the Westshore Marine & Leisure google plus page! Any owner seeking the last bit of speed from an outboard-powered boat should grab a yard stick. not sure that it's still used. 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. At least if its too long you can raise the motor or "build up" your transom. To measure your outboard motor shaft length, measure from the bottom of the mounting bracket where it rests on the transom to the top of the cavitation plate, this is the horizontal surface of the lower unit immediately above the propeller. Get the latest updates on new products and upcoming sales, 2023 Marine Parts Warehouse Incorporated Boaters who consider going with a higher mount can see increased speeds. (Putting a Happy boating! I mean it is better to be safe than sorry, am I right? Place the clubs bottom on the ground as though it were going to be used to strike a golf ball. Keep these numbers in mind if you ever have a need for a new outboard motor for your boat. The center is the point where your outboard motor is (ideally) located. Having the cavitation plate a bit lower than the transom is preferable to having it too high. The cookie is used to store the user consent for the cookies in the category "Performance". priceSelector: ".price--withoutTax, span.price.price--withTax", As a result, the issue is whether my boat need a short shaft or long shaft motor. This is the dimension you'll need when selecting a width for your outboard motor's mounting bracket. 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. If the height of the boat transom is off it can cause major issues. A reverse transom that sits too high can impact the propellers of the motor and motor bracket. and I'll explain it better, (or point you to someone that can help. Knowing how this can affect the overall operation of the boat is a factor to be considered. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. This distance is very important to the performance of you boat. The first order of business is to measure your boat for the ideal fit. Industry standards dictate that for short shaft engines the transom height should be 15. With this in mind, how can I determine if my outboard has a short or long shaft? Generally, the anti-ventilation plate on most engines is aligned with the bottom of the vessel. ), and place it on the bottom of the pad in the center. Usually speaking, the farther the outboard is set off the transom, the higher the propeller should be in the water (or the higher the outboard can be mounted). My family and I used it to fish, ski (yes, you can ski behind a pontoon boat), and cruise the lakes near our home. 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. Boat transomangles play a pivotal role in the flexibility of the boats trimming abilities. Long shafts are 20-inches long. document.getElementById('cloakd53b59933f6c3f2e8b59f1b4a6d41fa5').innerHTML = ''; Follow Westshore Marine & Leisure on Twitter! loadScript(ptScript); Offshore vessels are often equipped with a large mounting bracket so that the transom can be left at full height. If you decide to make some custom adjustments we have theexperience and know-howto make it happen. This is probably the worst case scenario out of the two. 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. Trimming in, trimming down, and trimming out are all terms that a beginning boater should learn. Then adjust the motor in a higher hole with a flat head screwdriver. Knowing the width, height and depth of your transom allows you to make several important decisions when selecting or purchasing a new outboard. The mounting height of an outboard motor can impact the speed and handling characteristics of the boat. Check the literature about your model boat online, and you may be surprised to find that the number is published for you. The propellers will also have trouble reaching the water. One of the great things about an outboard motor is how versatile it is. Triton. What are Apple Podcasts Subscriptions and Channels? This, however, is not recommended for the beginning boater. This could also affect your travelling capabilities on the boat trailer. This is handy if youre shopping for second-hand outboards or looking to sell the one that came with your boat. Read the following to get the optimal shaft length for outboard motors! Will Charpentier is a writer who specializes in boating and maritime subjects. The transom is the rear wall of the boat where the outboard engine is mounted in the middle. This website uses cookies to improve your experience while you navigate through the website. To do so, you will want to measure at the exact center of the transom from the very top to the very bottom. (function () { Your at your local outboard dealer shopping for a new motor and the salesman hits you with the question, "short or long shaft?". The transom is the flat vertical section at the rear of the boat. These allow the mounting of a standard length outboard behind the transom. parallel with the straight edge. Here we will guide you in how to get the right boat transom height. Step 2: Three Variables to Consider gtag('js', new Date()); This is measured by the propeller shaft being parallel to the vessels bottom. In step 3, add another 10 cm (4") to the previous calculation in order to develop the ideal shaft length. Again, make sure that you are measuring to the flat part of the brackets; Displacement hulled vessels like sailboats and workboats can benefit from a little more space between the hull and cavitation plate, but not much. Then finally test your outboard, if the mount is perfect. 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. You will also risk hitting bottom or submerge objects more frequently such as rocks or logs. But in many cases, its a little more complicated than that alone. addyd53b59933f6c3f2e8b59f1b4a6d41fa5 = addyd53b59933f6c3f2e8b59f1b4a6d41fa5 + 'vanssports' + '.' + 'com'; A long shaft engine requires a height of 20 and extra-long shaft engines will need a transom height of 25. Any questions? It does not store any personal data. These cookies ensure basic functionalities and security features of the website, anonymously. AztH ^zv_ cT,E1K/rAB54| Most of the time, adding a hydrofoil to an outboard improves performance. Like Westshore Marine & Leisure on Facebook! <>/ExtGState<>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 595.2 841.8] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> This measurement was approximately 4". relation to pad The current measurement is the ventilation plate is about 1 1/2" above the true keel line which is about 24" in front of the motor edge. Some boats are equipped with transom-hung outboards while others have a bracket. Gear Oil Quantity 195ml(6.6 Fl.oz.) I live for the weekends when I can go out on the water and escape the stress of life on land. How can you figure out what your transom angle is? 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. If your outboard motor height. endobj Basically, there are three main ways to measure motor 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. Expectedly, when the transom angle is zero, it means it is flat. Each one has a totally different effect on the boats performance. Whether your on a pontoon boat, fishing boat, or speedboat boating is always one of the best times you can have. Recommended Engine Oil 2-Stroke Outboard Motor Oil. I believe 20 to 21 inches is the optimum length for a lengthy shaft. Plus, a low transom cut is an invitation for the water to flood the boat. This alone can outweigh the negatives when deciding to adjust the mount upwards. It doesnt matter if you have a fiberglass boat, bay boat, big or small boat. The boater must also consider if the boat transomsupport is designed to bear the weight of a higher mount. Knowing how this can affect the overall operation of the boat is a factor to be considered. 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. Youll also want to pay attention when youre in shallow water because your prop will be lower than normal. Some fishing boats can handle the motor being underwater. Problems with getting the ventilation plate too low include slower hole-shot and lower top-end speeds. It is where the outboard is mounted, and some boat owners place the name of the boat. To achieve 35 mph with a 6 hp engine, the total weight is 135 lbs (boat motor fuel passengers). Oftentimes you will want to adjust the outboard shaft length in order to improve the boat performance such as speed. 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. hulls, such as Allisons, Bullets, Strokers, etc., this measurement could Yes, if there is adequate space while the engine is tilted in the up position, a larger shaft length than what is specified may be used. However, you will need an understanding of how the degrees will alter the boats usability. Amazon has plate extensions to allow adjustments without buying a new motor: T-H Marine Jack Plate Extension. What types of boat need an extra long shaft? Anything bigger than that your obviously going to need an extra long shaft. The clamp bracket on the latest Mercury Four-Stoke-model outboards has five mounting bolt holes spaced .75 inches apart. In the photo above, we've measured from the motor bracket to the top of Safely but briskly accelerate. debugMode: false, The pressure behind your hand dropped as you slid your hand back and forth through the water. Not to measure boat speed, but to gauge the mounting height of the outboard motor on the boat transom. You can order an outboard in lengths ranging from 15 inches to 30 inches, depending on its power output and possible uses. There Two years ago, I bought a Boston Whaler to fish off the coast. With some boats I have a pretty good idea as to what length motor should be hung on them. 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. How high exactly do you have to raise the transom?-. It is possible that the motor could hang low while transporting on the boat trailer causing future boat repairs. 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. :$I>M W$h"%U_yzIb?]NHg_G|r@nX eTf."SQ The amount of degrees the transom leans back from vertical is known as the transom angle. On this type of boat, if you are in doubt, default to the longer-shafted outboard. In the second photo, we've measure down from the top of the Detwiler Shaft lengths are available in increments of 5. to where the brackets were actually resting on the transom. Ten years ago I bought my first boat. enableMoreInfoLink: true, The faster your boat, the more critical it is to get the sizing just right. var h = d.getElementsByTagName("head"), 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. Engine Oil Type Genuine or Recommended 2str Engine Oil. Owners of bass boats, RIBs, or offshore fishing boats need to get this right. Most transom savers can support up to a 150HP motor, which is sufficient for most regular boats. actually have the propshaft above the pad.). If you are running a slower boat, the exact location of the ventilation plate is less important. 12 Small Fishing Boat Accessories to Buy Today. With it comes a lot of responsibility and new things to learn includingboat maintenanceand boat basics.