How the outboard will sit on the back of the boat depends on how the transom is designed. Before we start measuring the outboard shaft length, lets get it clear about whats referring to when we talk about the outboard shaft length. Always weigh the risks of making adjustments. If you decide to make adjustments, please consult a marine engine dealer about the boat design. A big NO. Trimming in, trimming down, and trimming out are all terms that a beginning boater should learn. Having the cavitation plate too low will cause excess drag and reduced performance at high speeds. Two years ago, I bought a Boston Whaler to fish off the coast. It does not store any personal data. And thats usually the case since the electric outboards are designed with larger and more efficient propeller that needs longer shaft. Engine Oil Mixing Ratio Fuel 50: Engine Oil 1. var interval = setInterval(function () { No one wants to have issues with a new transom or boat repairs. The transom in a boat today is a place to hang your outboard motor. A1: Broadly speaking, the outboard motor shaft length for pontoon boat, bass boat, or other larger boats should be long shaft. Get the latest updates on new products and upcoming sales, 2023 Marine Parts Warehouse Incorporated
your motor will be higher.) Offshore vessels are often equipped with a large mounting bracket so that the transom can be left at full height. If it measures anywhere from 17" to around 22", then your going to want to go with a long shaft motor. Generally, the anti-ventilation plate on most engines is aligned with the bottom of the vessel. Make sure that you are measuring straight up, at a 90 degree angle to
You may wonder how deep your prop should be in the water. This was the height of my 225 Yamaha on my TR21
Smaller inflatables and dinghies needshort shaft motors, whilst bigger boats require long or, in some circumstances, extreme long shaft versions. Step 4. actually have the propshaft above the pad.). document.getElementById('cloakd53b59933f6c3f2e8b59f1b4a6d41fa5').innerHTML = ''; 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. s.setAttribute("rel", "stylesheet"); To do so, measure from the stern (back) of the boat to the midpoint of the hull on both sides. Problems with getting the ventilation plate too low include slower hole-shot and lower top-end speeds. Figuring out how to measure motor height on a
Some fishing boats can handle the motor being underwater. boats.com is part of the Boats Group Network. d.addEventListener("DOMContentLoaded", function (e) { It was a 23-foot Crestliner Grand Cayman pontoon boat. Why Rebounding Is A Key Skill for Fouth Players To Learn, Tips For Attacking a Zone Defense as a Youth Basketball Team, Why This is a Big Deal for the Sports Betting Industry. var addyd53b59933f6c3f2e8b59f1b4a6d41fa5 = 'info' + '@'; This measurement is primarily designed for single motor propulsion. Many single-engine boats mount a smaller auxiliary motor for emergency use. He is a logoColor: "original", 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. Remanufactured 4 Cylinder 4-Stroke Cylinder Heads, Remanufactured 6 Cylinder 4-Stroke Cylinder Heads, Trim Relays, Trim Solenoids & Sending Units, Remanufactured V6 & V8 4-Stroke Cylinder Heads, Volvo Cobra SX Bearings and Bearing Carriers, Volvo Cobra SX Driveshaft, U-Joints & Parts, Volvo Cobra SX Transom Assembly & Bellows. While this is the case there is certain saltwater motors that are extra extra long at 30. Doing this can have adverse effects. Other boats that need long shafts are. August 9/08). Top 10 Choices for Boaters, Mercury Introduces 600HP V12 Verado Outboard Engine, The Outboard Expert: Tohatsu Propane Outboard Engine. Picking the right shaft length for your outboard is an essential step in getting the best performance from your boat. mpeSelector: ".pt-mpe", With this in mind, how can I determine if my outboard has a short or long shaft? The greater the number, the more the drive may sway (also called tuck under or negative trim). The height of the boat transom dictates the size of the outboard motor. (We wont go into name-calling here, but the actual term for the cavitation plate is an anti-ventilation plate.) Mounting the outboard motor in accordance with the industry standards is important. These cookies ensure basic functionalities and security features of the website, anonymously. By clicking Accept, you consent to the use of ALL the cookies. For most boaters this is a no brainer, but for the novice or inexperienced boater it may be a tougher question. Here we look at the effects of standard, lower and higher mounting. I hope this helps someone out in their search for a new or newer outboard this season. You can order an outboard in lengths ranging from 15 inches to 30 inches, depending on its power output and possible uses. disregard the "hooks" at the front of the
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. The outboard comes with mounting holes and brackets. A: Any boat that has a 21 to 27 inch aft transom will need an extra long shaft outboard. How high exactly do you have to raise the transom?-. Boat hulls are designed in three basic types that range from slow displacement and semi-displacement hulls to the fastest planing hulls. 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. How to Buy a Boat: Tips for a First Time Buyer, Top 10 New Fishing Boats for Under $20,000, What Type is Right for You? The prop will be in cleaner, harder water as it advances farther aft, making it more efficient. s = d.createElement("script"); 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? 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. If it measures 15" or with in a inch of that you will need a short shaft outboard. So in hopes that this will help out some new boaters this spring, here's a little rundown on outboard shaft sizes and how to figure out which one you actually need. displayMicroOffers: false, Industry standards dictate that for short shaft engines the transom height should be 15. "brackets". Happy boating! priceSelector: ".price--withoutTax, span.price.price--withTax", It is unsafe to have the engine block too close to the water on a low transom. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". window.dataLayer = window.dataLayer || []; You also have the option to opt-out of these cookies. (Any measurement given as "off the transom"
These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. Beginning boaters should be aware of the boats measurements. 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. Wherever the outboard clamping bracket is, use this as the basis for measurement. Lubrication System Engine Oil Mixed Gasoline. 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. manufacturer will recommend the outboard height according to the bracket shape and length. The performance of these boats depends on quite a lot of factors, but getting the outboard length just right is an essential first step. These are vertically aligned so the boater can make adjustments. However, you will need an understanding of how the degrees will alter the boats usability. 1 0 obj
You dont have to be a mathematician to determine the correct boat transom angle. 4 0 obj
How Transom Height Is Measured Be sure to measure carefully and research thoroughly before diving in. enableMoreInfoLink: true, The same is true for the newest, high-powered offshore fishing boats, where triple or quadruple motor setups are becoming more and more common. (616) 364-0666, On all contiguous US part orders over $100. }) } }); })(document); These two measurements will give you the length of the shaft you need. It is possible that the motor could hang low while transporting on the boat trailer causing future boat repairs. Say the 20 shaft is a long shaft length for gas engines, but it is a short shaft length for electric outboard motors. Among them will be first-timers or those who have recently purchased their boats. Buying a boat can be an exciting purchase. Place the clubs bottom on the ground as though it were going to be used to strike a golf ball. For boats equipped with a bracket, calculate the same measurement but based on the bracket and not the transom. 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. Increased RPM and additional horsepower feed the need for speed. To break it down a bit more for you: Short shafts are 15-inches long. e-mail
The form of a boats transom varies depending on the manufacturer and model. The transom is the rear wall of the boat where the outboard engine is mounted in the middle. If youre looking for a bracket that can handle motors of up to 10/15 horsepower, go no further. But, how do you measure it? 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. Its still smart to measure it yourself though, just in case, the design changed over the years. var h = d.getElementsByTagName("head"), Expectedly, when the transom angle is zero, it means it is flat. The average transom angle is around 14 degrees. I also love helping others, which is why I created this website. Read the measurement on the transoms bottom. As with anything, there are exceptions to the rule. 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. If you are running a twin-engine setup, then measure the same distance from each clamping plate to the bottom of the hull. To do so, you will want to measure at the exact center of the transom from the very top to the very bottom. Which Navigation Lights Does Your Boat Need? want to measure from the transom to the flat part of this bracket,
These are vertically aligned so the boater can make adjustments. var ptScript = "https://cdn.paytomorrow.com/js/pt-mpe.min.js"; I believe 20 to 21 inches is the optimum length for a lengthy shaft. ), and place it on the bottom of the pad in the center. Pretty easy to figure out but like I said its crucial to pairing a motor with a boat. If you go too short your more than likely going to cavitate and loose power. clearInterval(interval); Thats it. High powered boats usually only come in long and extra-long variants. These cookies will be stored in your browser only with your consent. Actually there is no designated letter for short shaft. 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. Anything bigger than that your obviously going to need an extra long shaft. As a result, the issue is whether my boat need a short shaft or long shaft motor. Add the two measurements and you get 6 1/2". 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. Like Westshore Marine & Leisure on Facebook! If the height of the boat transom is off it can cause major issues. 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. If you decide to make adjustments, please consult a marine engine dealer about the boatdesign. If you have a question or need additional information. His works have appeared in regional newspapers in North Dakota and in "North Dakota Horizons" and "Cowboys and Indians" magazines. Ill also explain the difference between short and long shafts and how they vary by type of boat. Where Onboard a Boat is the Transom Located and More About Transom Heights A propeller operates based on the height of the transom. How can you figure out what your transom angle is? Since the length of the shaft of your outboard is associated with the size boat, smaller engines will generally have shorter shafts. 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. storeDisplayName: "Marine Parts Warehouse", Check out some hot FAQs to help you get the proper outboard shaft lengths. But opting out of some of these cookies may affect your browsing experience. 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. x\[D~OUCO6[j](l%ay <8cylY{.L2s#]~U6A|Wj]-oo|mubqY6wbY_|!>Z8(RB:RHeTzOGO_=~t\ If it measures between 17 and 22, you'll want to go with a long shaft motor. To measure the transom height, measure from the center on for transom (rear of the boat). Beefier jack plates can be fitted should a boater be looking to mount an outboard with a shorter shaft than their transom demands. The transom is the back of the boat where the motor is hung. This email address is being protected from spambots. disregard the downward pointing "hooks" at the front of the
maxMicroAmount: 0.0, parallel with the straight edge. *The Factors indicates the adjustment affected by on your boat type, the outboard working environment, and the transom distance as discussed above. maxTerm: 36, A long shaft engine requires a height of 20 and extra-long shaft engines will need a transom height of 25. The cookie is used to store the user consent for the cookies in the category "Performance". 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". 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. 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. For vee-shaped hulls, the lowest spot of the hull will come to point, while on flat-bottomed boats it will be more or less level. 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. With it comes a lot of responsibility and new things to learn including boat maintenance and boat basics. PayTomorrow.mpeInit({ Here we will guide you in how to get the right boat transom height. 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. This is also known as the shaft length. (updated
} An inch or two probably wont make a big difference, but any more than that will lead to trouble. and I'll explain it better, (or point you to someone that can help. Whether you already own a boat or looking for your first watercraft we are here to service your needs. 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. A: The short answer is Yes. Most of the standard engined boats it takes shafts that are 15-30inches long. Basically, there are three main ways to measure motor
(function (d) { However, you will need an understanding of how the degrees will alter the boats usability. My family and I used it to fish, ski (yes, you can ski behind a pontoon boat), and cruise the lakes near our home. Also, how do you determine the length of an outboard transom? The boat transom can be flat with zero degree angles. Cutting the transom down is the only legal method to utilize a short shaft engine on a tall transom. You can find your Mercury outboard model code on an ID plate or sticker. straight edge on the top of the transom to "extend" it out
If you are running a slower boat, the exact location of the ventilation plate is less important. Not to measure boat speed, but to gauge the mounting height of the outboard motor on the boat transom. When the boat transom is too low, the motor could end up underwater. Some may call it a standard length while others may call it a short or a long shaft. What Kind of Fuel Does Your Marine Engine Need? 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. A: The answer varies by boat, but here are some rules of thumb for matching a short shaft outboard to your boat. To achieve this, the motor itself has to be attached at the correct height. 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. However, your boat will have slightly more drag which will reduce your maximum speed. var addy_textd53b59933f6c3f2e8b59f1b4a6d41fa5 = 'info' + '@' + 'vanssports' + '.' + 'com';document.getElementById('cloakd53b59933f6c3f2e8b59f1b4a6d41fa5').innerHTML += ''+addy_textd53b59933f6c3f2e8b59f1b4a6d41fa5+'<\/a>'; The height is approximately six inches higher than with a propeller. 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. If your boat planes, pay extra attention to getting the shaft length as close to perfect as possible. Attention: Remember to measure the outboard shaft length straight up and down instead of measuring along the transom. #2. It is very versatile as it generally . Its where the outboard motor is attached, and its also where some boat owners put the boats name. It also includes attaching the right engine. Then finally test your outboard, if the mount is perfect. 1855 Alpine Avenue NWGrand Rapids, MI 49504This email address is being protected from spambots. Each one has a totally different effect on the boats performance. 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. This alone can outweigh the negatives when deciding to adjust the mount upwards. The brackets can add 1 inch to the overall mounting height of the outboard. ), Al Shields
would be more accurate.) 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. Doing so, will put the propeller right below the boat. These cookies track visitors across websites and collect information to provide customized ads. Depending on the manufacturer, size names might change. resting on the transom if you had the motor all the way down on the boat
Then adjust the motor in a higher hole with a flat head screwdriver. motor brackets
If you went too long it would still work but it may lack in performance. 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. (function () { A yardstick will help you determine if your outboard engine is at the right height. Measure from the top of the straight edge to the center of the front
When trimming your motor, they provide you a greater bow response. jackplate to a point level with the top of the transom. xmlHttp.open('POST', 'https://bes.gcp.data.bigcommerce.com/nobot'); The lowest point will likely be directly under your drain plug if youve got one. out the confusion. For over five years he has worked as a newspaper reporter and historic researcher. Before we get started lets see what a boat transom is and what it does. 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. Displacement hulled vessels like sailboats and workboats can benefit from a little more space between the hull and cavitation plate, but not much. Is my outboard long or short shaft? Save my name, email, and website in this browser for the next time I comment. to where the brackets were actually resting on the transom. Boat transomangles play a pivotal role in the flexibility of the boats trimming abilities. With it comes a lot of responsibility and new things to learn includingboat maintenanceand boat basics. 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. If you have a jackplate, you may have to get a bit creative in your
To make the yard stick long enough to measure the length of all the clubs, tape the ruler to the top. A deep Vee hull will result in a different measurement than a flatter . C Cheaptoon Cadet Joined Aug 4, 2010 Messages 28 Aug 24, 2010 #4 Re: Motor height on pontoon? 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. Rebuilt - What You Need to Know, Lower Unit and Sterndrive Break-In Instructions. When it gets to the short side (14), When the inner corner of the square comes into touch with the transom, measure the distance between the inside corner of the square and the boat bottom (see drawing below). Amazon has plate extensions to allow adjustments without buying a new motor: T-H Marine Jack Plate Extension. Now that you have a better understanding of boat transom heights its time to take out the ruler and get the perfect measurements. It is where the outboard is mounted, and some boat owners place the name of the boat. Beyond motorboats designed for large outboards, you will see outboards hanging on the sterns of everything from small canoes to large cruising sailboats. This also means it can affect the safety of the boat. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. All you need to do is measure how much to rise. This would not be a good thing. Keith Allen, a 1979 graduate of Valley City State College, has worked at a variety of jobs including computer operator, medical clinic manager, radio talk show host and potato sorter. Once you know what will fit on your hull, you can fine-tune your choice based on the performance youre looking for and how you use the boat. The general guideline for longer shaft outboards is that the transom height should be at least 20 inches (50,8cm) above the waterline. So from there, I will try to help out by asking questions about your boat such as what type it is and the length. Brackets are also handy for boats that do not have flat transoms, like canoe-stern sailboats or fan-tailed motor vessels. What's the best height for my boat motor? Finding the right size is a matter of looking at what youve got and taking out the measuring tape. s.setAttribute("type", "text/javascript"); This cookie is set by GDPR Cookie Consent plugin. if (PayTomorrow) { Check out the full chart of the Mercury outboard model code and its features. A2: Instead of changing to the short outboard shaft, you can try the Jack Plate first. Other boats that need extra long shafts are: Read my other articles on outboard motors. Engine Oil Type Genuine or Recommended 2str Engine Oil. However, the motor should not be raised more than 5 inches above the standard position. up to the bottom of the motor brackets, (as in #1). (Putting a
Plus, a low transom cut is an invitation for the water to flood the boat. Outboard motors can be fitted to a variety of boats, so manufacturers have standardized their engines to go on virtually anything. Each one has a totally different effect on the boats performance. Knowing how this can affect the overall operation of the boat is a factor to be considered. Here we will guide you in how to get the right boat transom height. It will ensure that the outboards trim will be effective, and it will save you gas too. Beginning boaters should be aware of the boats measurements. Step 2: Three Variables to Consider The shaft length for outboard motors has nothing to do with the water line. I would ask you to go back and measure the transom of your boat. Raising an outboard higher on the transom can reduce drag and raise top speed. Measuring the shaft length can be done in various ways, but the most common way is by using a tape measure. The outboard comes with mounting holes and brackets. If your boat is newer and the manufacturer is still in business, you might also want to try to give them a call. 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. 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. However, with the outboard shaft length too short, meaning the prop is too close to the surface, the engine is likely to ventilate and therefore slip on acceleration or lose power. Measure from the top of the transom to the bottom of the hull. While this is the case there is certain saltwater motors that are extra extra long at 30 and 35 shaft. %
Repowering your boat is one of the most expensive upgrades you can make. You'll need a short shaft outboard if it's 15 or less than an inch shorter. Attention: Remember to measure the outboard shaft length straight up and down instead of measuring along the transom. publicId: "32bf3437d1346295e03ebcf545f9c839", This placement is not only recommended but it will give you the best performance compared to something that is too long or too short. It doesnt matter if you have a fiberglass boat, bay boat, big or small boat. It is extremely important that the boater understands the significance of the transom's height. The motor is what powers the boat so the two go hand-in-hand. But in many cases, its a little more complicated than that alone. Learn More About Your Boats Systems By Joining The Born Again Boating Academy! Any questions? As mentioned above, the operation of the propeller relies on the transom height. s.setAttribute("src", script); Then open up the clamp bucket. center of the propshaft. Small portable outboards ranging from 2 to 20 horsepower are usually sold only in short or long shaft versions. If you are looking to repower, they may be able to offer some sage advice. Check out the Westshore Marine & Leisure Youtube page! When the boattransom is too low, the motor could end up underwater. Outboard Motor Shaft Length: How do I measure?