If it measures anywhere from 17" to around 22", then your going to want to go with a long shaft motor. Then finally test your outboard, if the mount is perfect. Small motors built for sailboats might come in a unique configuration with an extremely long shaft since these are mounted higher off the water. Check out some hot FAQs to help you get the proper outboard shaft lengths. The clamp bracket is designed so that the engine's mounting height on the transom can be adjusted higher than standard. I show you how to consistently measure your prop to pad height. Now that you have a better understanding of boat transom heights its time to take out the ruler and get the perfect measurements. Ill also explain the difference between short and long shafts and how they vary by type of boat. In lower mounting, the engine is set lower than the recommended standard. The transom in a boat today is a place to hang your outboard motor. You also might not be able to lift the outboard out of the water entirely for storage. This email address is being protected from spambots. Doing so, will put the propeller right below the boat. Knowing how this can affect the overall operation of the boat is a factor to be considered. boats.com is part of the Boats Group Network. No matter what size of boat you are running, one of the most critical choices you can make when buying an outboard motor is the shaft length. Before we get started lets see what a boat transom is and what it does. Or it can have an angle degree as high as 30. (function (d) { It is extremely important that the boater understands the significance of the transom's height. primeApr: 12.99, Your goal is to measure how the outboard will sit, so start from the clamping plate and follow the centerline of the hull. Place the point of a yardstick at the middle of the top of the boat transom. Recommended Engine Oil 2-Stroke Outboard Motor Oil. The height of the boat transom dictates the size of the outboard motor. Copyright 2017 Dealer Spike All Rights Reserved. Save my name, email, and website in this browser for the next time I comment. A2: Instead of changing to the short outboard shaft, you can try the Jack Plate first. ), and place it on the bottom of the pad in the center. xmlHttp.open('POST', 'https://bes.gcp.data.bigcommerce.com/nobot'); Measure the area of the transom directly where the engine will be mounted. h[0].appendChild(s); Typical motor lengths include the following. parallel with the straight edge. There are also specialty motor shaft lengths. Cavitation plates are used on the bottom components of boats to help them operate better. To do so, take a measurement from the very top to the very bottom of the transom in the precise center. #3. As mentioned above, the operation of the propeller relies on the transom height. There is a simple test to see if your outboard motor is set at the best height. Most of the standard engined boats it takes shafts that are 15-30inches long. In the second photo, we've measure down from the top of the Detwiler
To make the yard stick long enough to measure the length of all the clubs, tape the ruler to the top. If we run into that scenario, I would still show you the different options of motors and go over pricing, but I would also ask you to hold off and do one thing before you pull the trigger. 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 clamp bracket on the latest Mercury Four-Stoke-model outboards has five mounting bolt holes spaced .75 inches apart. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. Its important to note that manufacturers call their models different things. However, there may be times when a boater strays away from these recommendations. Industry standards dictate that for short shaft engines the transom height should be 15. Beginning boaters should be aware of the boats measurements. Boat hulls are designed in three basic types that range from slow displacement and semi-displacement hulls to the fastest planing hulls. This is measured by the propeller shaft being parallel to the vessels bottom. Check the literature about your model boat online, and you may be surprised to find that the number is published for you. While this is the case there is certain saltwater motors that are extra extra long at 30. Having the cavitation plate too low will cause excess drag and reduced performance at high speeds. 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. This could also affect your travelling capabilities on the boat trailer. It also cuts into speed and fuel efficiency. The pros and cons of properly . The cookie is used to store the user consent for the cookies in the category "Analytics". This restriction includes most fishing boats and longer sailboats. It varies between different motors and boats. Picking the right shaft length is mostly a factor of the transom height or the back of the boat. Allowing the propeller to pull water from underneath and push it out behind the boat. motor brackets
window.dataLayer = window.dataLayer || []; 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. A1: Broadly speaking, the outboard motor shaft length for pontoon boat, bass boat, or other larger boats should be long shaft. Buying a boat can be an exciting purchase. 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. displayPrimeOffers: true, In the past, though, it housed the officers and captain of 17th, 18th and 19th century sailing ships. These allow the mounting of a standard length outboard behind the transom. 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. If you decide to make some custom adjustments we have theexperience and know-howto make it happen. With this in mind, how can I determine if my outboard has a short or long shaft? For example, you can have the Mercury outboard shaft length by model code. Outboard motors can be fitted to a variety of boats, so manufacturers have standardized their engines to go on virtually anything. Trimming in, trimming down, and trimming out are all terms that a beginning boater should learn. stream
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. Figuring out how to measure motor height on a
Which Navigation Lights Does Your Boat Need? 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? The transom is the rear wall of the boat where the outboard engine is mounted in the middle. maxTerm: 36, If the height of the boat transom is off it can cause major issues. 7. The height is approximately six inches higher than with a propeller. "brackets". Other boats that need extra long shafts are: Read my other articles on outboard motors. hulls, such as Allisons, Bullets, Strokers, etc., this measurement could
These two measurements will give you the length of the shaft you need. Boat Transom Heights The Beginners Guide, Buying a boat can be an exciting purchase. Commonly, the transom angle ranges from 0-30 degrees, with the average transom angle set at 14 degrees. Each one has a totally different effect on the boats performance. Read the measurement on the transoms bottom. bracket. <>
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. The lowest point will likely be directly under your drain plug if youve got one. If you are looking to repower, they may be able to offer some sage advice. So how to measure outboard shaft length? center of the propshaft. s.setAttribute("rel", "stylesheet"); 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. The engine must be linked to the transom at the proper height for a propeller to best meet specific boating demands. Get the latest updates on new products and upcoming sales, 2023 Marine Parts Warehouse Incorporated
When fighting waves from the stern, a 20-inch transom is considerably safer. 3 0 obj
})(); As with anything, there are exceptions to the rule. 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 a jackplate, you may have to get a bit creative in your
This is somewhat similar to #2, in that you are again measuring with a
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'+addy_textd53b59933f6c3f2e8b59f1b4a6d41fa5+'<\/a>'; Any questions? Industry standards dictate that for short shaft engines the transom height should be 15. If you have a small boat with a 15 to 17 inch aft transom, youll most likely need a short shaft outboard. If it measures between 17 and 22, you'll want to go with a long shaft motor. I run a 9.9 Mercury Bigfoot 20" shaft off the swim platform of my 89 Trophy 2160. Repowering your boat is one of the most expensive upgrades you can make. All boats are different, and the motor manufacturers produce a variety of standard lengths. With the long side (22 1/2), place a carpenters square ) in opposition to the keel. Take a long straight edge, (long carpenter's level or long
This also means it can affect the safety of the boat. Happy boating! These are vertically aligned so the boater can make adjustments. There is a simple test to see if your outboard motor is set at the best height. You can find your Mercury outboard model code on an ID plate or sticker. It doesnt matter if you have a fiberglass boat, bay boat, big or small boat. 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). The motor length corresponds to the transom height of the boat, measured from the keel to gunwale at the transom. Place the clubs bottom on the ground as though it were going to be used to strike a golf ball. If the propeller fails to ventilate, the motor is mounted to low. Oftentimes you will want to adjust the outboard shaft length in order to improve the boat performance such as speed. You need JavaScript enabled to view it. How to Measure Transom Height For vessels with transom-mounted outboards, you can easily figure out which type of outboard you need to get. from the transom. But opting out of some of these cookies may affect your browsing experience. Measure straight down to the lowest point on the hull. This is the dimension you'll need when selecting a width for your outboard motor's mounting bracket. Boat transomangles play a pivotal role in the flexibility of the boats trimming abilities. What are Apple Podcasts Subscriptions and Channels? The boater must also consider if the boat transomsupport is designed to bear the weight of a higher mount. This, however, is not recommended for the beginning boater. This cookie is set by GDPR Cookie Consent plugin. endobj
measuring; you may have to "extend" the flat part of the
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. Higher mounting decisions should be left to the professionals. You
Knowing how this can affect the overall operation of the boat is a factor to be considered. :$I>M W$h"%U_yzIb?]NHg_G|r@nX eTf."SQ mpeInit(); Outboard Motor Shaft Length: How do I measure? Of course, its always best to go with standard practices when choosing thebest boat engine. It is very versatile as it generally . The transom is the back of the boat where the motor is hung. Shaft lengths are available in increments of 5. Doing this can have adverse effects. 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. Whether you already own a boat or looking for your first watercraft we are here to service your needs. It is possible that the motor could hang low while transporting on the boat trailer causing future boat repairs. A: Any boat that has a 21 to 27 inch aft transom will need an extra long shaft outboard. AztH
^zv_ cT,E1K/rAB54| 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. 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. Your at your local outboard dealer shopping for a new motor and the salesman hits you with the question, "short or long shaft?". You dont have to be a mathematician to determine the correct boat transom angle. One of the great things about an outboard motor is how versatile it is. What matters is the actual measurement in the specifications, not the name. You reply, "Im not sure, I think its a long". Displacement hulled vessels like sailboats and workboats can benefit from a little more space between the hull and cavitation plate, but not much. However, the motor should not be raised more than 5 inches above the standard position. The transom is the boats flat vertical part at the back. Raising the motor increases the speed of the boat while decreasing the effort needed to turn 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. The greater the number, the more the drive may sway (also called tuck under or negative trim). Youll need a short shaft outboard if its 15 or less than an inch shorter. relation to pad
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. Another important measurement is the transom angle. The transom angle is the vertical incline of the transom and is measured in degrees. Because of the increased friction, cavitation reduces efficiency. On the downside, a higher mount can interfere with the boaters steering capabilities. This cookie is set by GDPR Cookie Consent plugin. The prop will be in cleaner, harder water as it advances farther aft, making it more efficient. enableMoreInfoLink: true, priceSelector: ".price--withoutTax, span.price.price--withTax", If it measures 15" or with in a inch of that you will need a short shaft outboard. height (that I'm aware of); probably the most common is:
Wherever the outboard clamping bracket is, use this as the basis for measurement. My family and I used it to fish, ski (yes, you can ski behind a pontoon boat), and cruise the lakes near our home. If you go too short your more than likely going to cavitate and loose power. A long shaft engine requires a height of 20 and extra-long shaft engines will need a transom height of 25. 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. I would also recommend finding your maximum horsepower rating which is located on the yellow coast guard tag towards the back of your boat. Since the length of the shaft of your outboard is associated with the size boat, smaller engines will generally have shorter shafts. The cookie is used to store the user consent for the cookies in the category "Performance". 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. As with anything, there are exceptions to the rule. up to the bottom of the motor brackets, (as in #1). And thats usually the case since the electric outboards are designed with larger and more efficient propeller that needs longer shaft. This measurement would be the inches of
Engine Oil Mixing Ratio Fuel 50: Engine Oil 1. The cavitation plate is the horizontal surface of the lower unit immediately above the propeller. var BCData = {"csrf_token":"d7ecb6b56891bb66aee12dbc01a80162b3ed582c1acbe30f16fc9f1b2abc362f"}; It is where the outboard is mounted, and some boat owners place the name of the boat. For really big boats, the biggest and baddest six- or eight-cylinder outboards can have extra-extra long shafts up to 30 inches. The most common percent angle is probably 12, however spec sheets for O/B and I/O boats may show 10 percent, 12 percent, and 14 degrees. <>/Metadata 127 0 R/ViewerPreferences 128 0 R>>
Boat transom angles play a pivotal role in the flexibility of the boats trimming abilities. To achieve this, the motor itself has to be attached at the correct height. Extra-long shafts are 25-inches long. actually have the propshaft above the pad.). Smaller boats may use adjustable jack plates that can be changed to fit any outboard. 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. The height of the boat transom dictates the size of the outboard motor. Amazon has plate extensions to allow adjustments without buying a new motor: T-H Marine Jack Plate Extension. Anything bigger than that your obviously going to need an extra long shaft. 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. Some boats are equipped with transom-hung outboards while others have a bracket. 12 Small Fishing Boat Accessories to Buy Today. See When St. Peters Basketball Games Are Today! #1: Height
not sure that it's still used. Among them will be first-timers or those who have recently purchased their boats. Depending on the manufacturer, size names might change. It also decreases the boats lift and increases the time it takes for the boat to reach plane. It doesnt matter if you have a fiberglass boat, bay boat, big or small boat. And the rule of thumb is that you should keep the cavitation plate level with the bottom or keel of the 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. C Cheaptoon Cadet Joined Aug 4, 2010 Messages 28 Aug 24, 2010 #4 Re: Motor height on pontoon? Look at the part of your motor that would be
Outboards designed for saltwater applications usually have longer shafts. With the outboard shaft length too long, meaning the prop is too deep in the water, the engine wont be as efficient, and the fuel burn is high. Owners of bass boats, RIBs, or offshore fishing boats need to get this right. Bass boats, ski boats, or center cockpit vessels will want to double-check their measurements to get it just right. manufacturer will recommend the outboard height according to the bracket shape and length. One of the main concerns is causing the engine to overheat if not enough water reaches the engine to keep it cool. The brackets can add 1 inch to the overall mounting height of the outboard. } *The Factors indicates the adjustment affected by on your boat type, the outboard working environment, and the transom distance as discussed above. This alone can outweigh the negatives when deciding to adjust the mount upwards. If you have a short shaft motor, the distance between the top of the transom and the bottom of the boat should be between 15 and 16 inches. Always weigh the risks of making adjustments. Outboard shaft length plays a crucial role in the performance of your boat. On this type of boat, if you are in doubt, default to the longer-shafted outboard. xmlHttp.send('{"store_id":"369079","timezone_offset":"-5","timestamp":"2023-03-04T05:39:31.71020200Z","visit_id":"e2642be3-34e5-4a48-b89d-639d139834e0","channel_id":1}'); If youre looking for a bracket that can handle motors of up to 10/15 horsepower, go no further. The boater must also consider if the boat transom support is designed to bear the weight of a higher mount. The same is true for the newest, high-powered offshore fishing boats, where triple or quadruple motor setups are becoming more and more common. Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. Basically, there are three main ways to measure motor
As mentioned above, the operation of the propeller relies on the transom height. Thats it. 4 0 obj
Triton. Chances are the boat was designed with a specific size of outboard in mind.
It will ensure that the outboards trim will be effective, and it will save you gas too. Step 2 requires the propeller's radius (check the user manual and then the technical drawing).