Cutting the transom down is the only legal method to utilize a short shaft engine on a tall transom. Mounting the outboard motor in accordance with the industry standards is important. With more than a decade of experience cruising the lakes in my Crestliner Grand Cayman pontoon boat and my Boston Whaler, I now want to share everything I've learned with my community here at Boating Hub. Ill also explain the difference between short and long shafts and how they vary by type of boat. In addition, motor totes will not harm the finish of the lower unit. "brackets". For slower boats, its less critical to. C Cheaptoon Cadet Joined Aug 4, 2010 Messages 28 Aug 24, 2010 #4 Re: Motor height on pontoon? The cookies is used to store the user consent for the cookies in the category "Necessary". Whether you already own a boat or looking for your first watercraft we are here to service your needs. In the past, though, it housed the officers and captain of 17th, 18th and 19th century sailing ships. Beefier jack plates can be fitted should a boater be looking to mount an outboard with a shorter shaft than their transom demands. The brackets can add 1 inch to the overall mounting height of the outboard. s.setAttribute("src", script); Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. All you need to do is measure how much to rise. 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. The boat transom can be flat with zero degree angles. 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. 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. The mounting height of an outboard motor can impact the speed and handling characteristics of the boat. However, your boat will have slightly more drag which will reduce your maximum speed. Also, how do you determine the length of an outboard transom? The collapsing bubbles are loaded with extremely low-pressure water vapor, which causes damage to a variety of surfaces as they collapse. % var path = 'hr' + 'ef' + '='; This alone can outweigh the negatives when deciding to adjust the mount upwards. (3) Move horizontally across the chart until you hit the graph curve. This alone can outweigh the negatives when deciding to adjust the mount upwards. When you measure the width of the stern, mark the center with a grease pencil. Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. 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}'); When the right length motor is hung on the transom of a boat, the cavitation plate (the large plate that extends out over the propeller) should be even with the very bottom of the boat. Get the latest updates on new products and upcoming sales, 2023 Marine Parts Warehouse Incorporated The transom is the flat vertical section at the rear of the boat. parallel with the straight edge. You can use a longer shaft than recommended and your boat will work fine. Expectedly, when the transom angle is zero, it means it is flat. Problems with getting the ventilation plate too low include slower hole-shot and lower top-end speeds. Extra-long shafts are 25-inches long. 12 Small Fishing Boat Accessories to Buy Today. Boat transomangles play a pivotal role in the flexibility of the boats trimming abilities. There is a simple test to see if your outboard motor is set at the best height. Small portable outboards ranging from 2 to 20 horsepower are usually sold only in short or long shaft versions. Among them will be first-timers or those who have recently purchased their boats. Read the measurement on the transoms bottom. MarinePartsMan.com also says that V6 bass-boat engines have a 20-inch shaft. It is very versatile as it generally . Industry standards dictate that for short shaft engines the transom height should be 15. The clamp bracket is designed so that the engine's mounting height on the transom can be adjusted higher than standard. The outboard shaft length is the vertical distance between the top of the mounting clamp bracket and the bottom of the cavitation plate (aka the ventilation plate). This cookie is set by GDPR Cookie Consent plugin. The outboard comes with mounting holes and brackets. 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. Many single-engine boats mount a smaller auxiliary motor for emergency use. Mounting the outboard a little bit lower than the standard point could avoid the possible ventilation and slip on acceleration. What's the best height for my boat motor? A long shaft engine requires a height of 20 and extra-long shaft engines will need a transom height of 25. Typical motor lengths include the following. If the propeller fails to ventilate, the motor is mounted to low. The boater must also consider if the boat transom support is designed to bear the weight of a higher mount. Look at the part of your motor that would be Ideally, you want the outboards cavitation plate, also called the anti-ventilation plate, to be at the same level as the bottom of your hull. Height Measurement: Recommended Shaft Length: 14" - 17.25" 15" Shaft (Short) 17.25" - 19.5" Varies by application 19.5" - 22.5" PayTomorrow.mpeInit({ relation to pad var prefix = 'ma' + 'il' + 'to'; The point where these measurements intersect is your centerline. maxTerm: 36, Some may call it a standard length while others may call it a short or a long shaft. My family and I used it to fish, ski (yes, you can ski behind a pontoon boat), and cruise the lakes near our home. For example, you can have the Mercury outboard shaft length by model code. Later in the article is an image that shows you exactly where to measure. If your boat is newer and the manufacturer is still in business, you might also want to try to give them a call. The cookie is used to store the user consent for the cookies in the category "Analytics". Step 2 requires the propeller's radius (check the user manual and then the technical drawing). Another important measurement is the transom angle. This restriction includes most fishing boats and longer sailboats. If the propeller fails to ventilate, the motor is mounted to low. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. Having the cavitation plate a bit lower than the transom is preferable to having it too high. I would also recommend finding your maximum horsepower rating which is located on the yellow coast guard tag towards the back of your boat. maxMicroAmount: 0.0, Doing so, will put the propeller right below the boat. 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. 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. var BCData = {"csrf_token":"d7ecb6b56891bb66aee12dbc01a80162b3ed582c1acbe30f16fc9f1b2abc362f"}; To sum up, there is a simple calculator of the shaft length for outboard motors: Outboard Shaft Length = Transom Height +/- Factors. Lubrication System Engine Oil Mixed Gasoline. Many boat transoms are modified to use a different length of outboard by using a bracket. 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. You may wonder how deep your prop should be in the water. The standard shaft length for most outboard engines less than 125 horsepower is 20 inches. x\[D~OUCO6[j](l%ay <8cylY{.L2s#]~U6A|Wj]-oo|mubqY6wbY_|!>Z8(RB:RHeTzOGO_=~t\ straight edge on the top of the transom to "extend" it out The propellers will also have trouble reaching the water. s.setAttribute("rel", "stylesheet"); 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. window.dataLayer = window.dataLayer || []; When trimming your motor, they provide you a greater bow response. Higher mounting decisions should be left to the professionals. To do so, you will want to measure at the exact center of the transom from the very top to the very bottom. 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. Some fishing boats can handle the motor being underwater. #3. s.setAttribute("type", "text/javascript"); When measuring the transom height, you should start from the hull's bottom at the boat's center line up to the top of the transom. Although the longer outboard shaft length can lead to lower speed and more drag, the boat can push a heavier load. However, youll notice a little increase in drag and a decrease in top-end performance. Now that you have a better understanding of boat transom heights its time to take out the ruler and get the perfect measurements. All things considered, sticking with the industry standard is best for the beginner. The height of the boat transom dictates the size of the outboard motor. 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. 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. The lowest point will likely be directly under your drain plug if youve got one. Cavitation is when the propeller is out of the water due to the boat forming a wake of "air bubbles" or "vapor cavities" around the prop. 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. 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. However, there may be times when a boater strays away from these recommendations. This is measured by the propeller shaft being parallel to the vessels bottom. not sure that it's still used. storeDisplayName: "Marine Parts Warehouse", The cavitation plate is the horizontal surface of the lower unit immediately above the propeller. How can you figure out what your transom angle is? Your email address will not be published. There are 2 steps to help get a relatively accurate figure. The average transom angle is around 14 degrees. Smaller boats may use adjustable jack plates that can be changed to fit any outboard. 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. If it measures 15" or with in a inch of that you will need a short shaft outboard. However, the shaft length for smaller boats could be long or short depending on its style, speed requirement, etc. This measurement was approximately 4". Beginning boaters should be aware of the boats measurements. If you decide to make adjustments, please consult a marine engine dealer about the boatdesign. 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. var ptScript = "https://cdn.paytomorrow.com/js/pt-mpe.min.js"; 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. Wherever the outboard clamping bracket is, use this as the basis for measurement. This will keep the prop in the water when the boat pitches in waves, or hobby-horses. It is possible that the motor could hang low while transporting on the boat trailer causing future boat repairs. Place the bracket on the transom to the left of the main outboard or rudder. If mounting directly to a boat transom: Measure from the top of the transom down to the bottom of the hull or keel (lowest point). If youre looking for a bracket that can handle motors of up to 10/15 horsepower, go no further. Measure from there down to the top of the cavitation plate, also known as the anti-ventilation plate. Check out the full chart of the Mercury outboard model code and its features. 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. The transom is the back of the boat where the motor is hung. It doesnt matter if you have a fiberglass boat, bay boat, big or small boat. 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. I show you how to consistently measure your prop to pad height. Because of the increased friction, cavitation reduces efficiency. Oftentimes you will want to adjust the outboard shaft length in order to improve the boat performance such as speed. These allow the mounting of a standard length outboard behind the transom. function gtag(){dataLayer.push(arguments);} <>/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. The cookie is used to store the user consent for the cookies in the category "Performance". How the outboard will sit on the back of the boat depends on how the transom is designed. } You need JavaScript enabled to view it. :$I>M W$h"%U_yzIb?]NHg_G|r@nX eTf."SQ Before we get started lets see what a boat transom is and what it does. Its still smart to measure it yourself though, just in case, the design changed over the years. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". The shaft length for outboard motors has nothing to do with the water line.

Dasani Promotional Campaign Car Wrap, Ihra Bracket Finals 2021 Dragway 42, Credit Score Needed For Crutchfield, Hensel Phelps General Superintendent Salary, The Ooltewah Club Membership Cost, Articles H