If you have a jackplate, you may have to get a bit creative in your parallel with the straight edge. out the confusion. enableMoreInfoLink: true, 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 Two years ago, I bought a Boston Whaler to fish off the coast. What types of boat need an extra long shaft? 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. Any owner seeking the last bit of speed from an outboard-powered boat should grab a yard stick. Mounting the outboard motor in accordance with the industry standards is important. 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. To achieve 35 mph with a 6 hp engine, the total weight is 135 lbs (boat motor fuel passengers). Beginning boaters should be aware of the boats measurements. boats.com, 1221 Brickell Avenue, 23rd Floor, Miami, FL 33131, USA. Doing this can have adverse effects. Save my name, email, and website in this browser for the next time I comment. displayMicroOffers: false, Simply start with the engine in idle, followed bytrimming the motor out by one-half to full trim. 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. By clicking Accept, you consent to the use of ALL the cookies. var interval = setInterval(function () { Some fishing boats can handle the motor being underwater. A reverse transom that sits too high can impact the propellers of the motor and motor bracket. Will Charpentier is a writer who specializes in boating and maritime subjects. 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. Although the longer outboard shaft length can lead to lower speed and more drag, the boat can push a heavier load. This is a measurement that has been used for BassCats, I'm As summer approaches there will be more boaters taking to the water. However, the shaft length for smaller boats could be long or short depending on its style, speed requirement, etc. 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. Many boat transoms are modified to use a different length of outboard by using a bracket. 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. 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 distance between the ends of a transom is measured in inches. Of course, its always best to go with standard practices when choosing thebest boat engine. 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. 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-To: Pick A Great Portable Outboard Motor (2023 Guide) There is a simple test to see if your outboard motor is set at the best height. The cookie is used to store the user consent for the cookies in the category "Performance". Pad to bottom of A2: Instead of changing to the short outboard shaft, you can try the Jack Plate first. As mentioned above, the operation of the propeller relies on the transom height. There are instances where a lower mount may be okay. I live for the weekends when I can go out on the water and escape the stress of life on land. To do so, you will want to measure at the exact center of the transom from the very top to the very bottom. Its where the outboard motor is attached, and its also where some boat owners put the boats name. Also, how do you determine the length of an outboard transom? |. 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. Boaters who consider going with a higher mount can see increased speeds. The shaft length for outboard motors has nothing to do with the water line. storeDisplayName: "Marine Parts Warehouse", How To Mount An Outboard Motor Properly - Start to Finish! 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. If you decide to make some custom adjustments we have theexperience and know-howto make it happen. Say the 20 shaft is a long shaft length for gas engines, but it is a short shaft length for electric outboard motors. I mean, who wants to purchase something as expensive as an outboard to only realize you bought the wrong one. What Types of Documents Can be Sent to your Kindle Library? 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. With it comes a lot of responsibility and new things to learn including, Why your boat transom needs to be the right height, The pros and cons of properly mounting the outboard motor to the transom, Standard mounting is always best for the beginner, Of course, its always best to go with standard practices when choosing the, Lower mounting is not for the beginning boater, Mounting the motor lower on the boat transom, There is a simple test to see if your outboard motor is set at the best height. It is possible that the motor could hang low while transporting on the boat trailer causing future boat repairs. You will also risk hitting bottom or submerge objects more frequently such as rocks or logs. 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. A big NO. While this is the case there is certain saltwater motors that are extra extra long at 30. <>/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 is the dimension you'll need when selecting a width for your outboard motor's mounting bracket. Some outboards have a serial number that tells you which shaft length to go for. maxMicroAmount: 0.0, If it measures 15" or with in a inch of that you will need a short shaft outboard. Long Shaft vs. Short Shaft Outboard (What Are the Differences?) To sum up, there is a simple calculator of the shaft length for outboard motors: Outboard Shaft Length = Transom Height +/- Factors. Raising an outboard higher on the transom can reduce drag and raise top speed. ), Al Shields Allowing the propeller to pull water from underneath and push it out behind the boat. Check the literature about your model boat online, and you may be surprised to find that the number is published for you. What is Transom Height? d.addEventListener("DOMContentLoaded", function (e) { Now that you have a better understanding of boat transom heights its time to take out the ruler and get the perfect measurements. 4 0 obj Get the latest updates on new products and upcoming sales, 2023 Marine Parts Warehouse Incorporated Follow Westshore Marine & Leisure on Wordpress! 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. endobj trimming the motor out by one-half to full trim. Measuring Motor Height - BassBoat Central Most of the time, adding a hydrofoil to an outboard improves performance. You can use a longer shaft than recommended and your boat will work fine. These two measurements will give you the length of the shaft you need. Mounting the outboard a little bit lower than the standard point could avoid the possible ventilation and slip on acceleration. Place the clubs bottom on the ground as though it were going to be used to strike a golf ball. It will ensure that the outboards trim will be effective, and it will save you gas too. Lubrication System Engine Oil Mixed Gasoline. The brackets can add 1 inch to the overall mounting height of the outboard. Take the center measurement from the top to the bottom of the hull. If it measures anywhere from 17" to around 22", then your going to want to go with a long shaft motor. Thats a fairly simple list of symptoms, but if your motor is too low, youll probably notice at least one of them. LOYALHEARTDY Outboard Motor 6 HP 2-Stroke Inflatable Fishing 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. And thats usually the case since the electric outboards are designed with larger and more efficient propeller that needs longer shaft. 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. However, you will need an understanding of how the degrees will alter the boats usability. Boat hulls are designed in three basic types that range from slow displacement and semi-displacement hulls to the fastest planing hulls. Measuring the shaft length can be done in various ways, but the most common way is by using a tape measure. 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. Theyre also useful if the back of your boat has a non-standard measurement. The engine must be linked to the transom at the proper height for a propeller to best meet specific boating demands. Picking the right shaft length is mostly a factor of the transom height or the back of the boat. Guide to Boat Transom Heights - Marine Parts Warehouse bassboat can be a bit confusing at times; hopefully this will help sort displayPrimeOffers: true, Extra-long shafts are 25-inches long. The Effects of Standard, Lower and Higher Mounting. The pros and cons of properly . Outboard Motor Shaft Length For Pontoon Boat - Survival Tech Shop 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 clamp bracket is designed so that the engine's mounting height on the transom can be adjusted higher than standard. The same is true for the newest, high-powered offshore fishing boats, where triple or quadruple motor setups are becoming more and more common. minAmount: 300.0, It doesnt matter if you have a fiberglass boat, bay boat, big or small boat. Some fishing boats can handle the motor being underwater. Check out the full chart of the Mercury outboard model code and its features. 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". 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). For example, you can have the Mercury outboard shaft length by model code. (3) Move horizontally across the chart until you hit the graph curve. With it comes a lot of responsibility and new things to learn including boat maintenance and boat basics. How Transom Height Is Measured This website uses cookies to improve your experience while you navigate through the website. Bass boats, ski boats, or center cockpit vessels will want to double-check their measurements to get it just right. Measure from the top of the transom to the bottom of the hull. The standard shaft length for most outboard engines less than 125 horsepower is 20 inches. The boat transom can be flat with zero degree angles. In step 3, add another 10 cm (4") to the previous calculation in order to develop the ideal shaft length. Other boats that need long shafts are. I hope this helps someone out in their search for a new or newer outboard this season. Smaller inflatables and dinghies needshort shaft motors, whilst bigger boats require long or, in some circumstances, extreme long shaft versions. Cutting the transom down is the only legal method to utilize a short shaft engine on a tall transom. One of the main concerns is causing the engine to overheat if not enough water reaches the engine to keep it cool. Whether you already own a boat or looking for your first watercraft we are here to service your needs. 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? If you decide to make adjustments, please consult a marine engine dealer about the boatdesign. Industry standards dictate that for short shaft engines the transom height should be 15. The boater must also consider if the boat transom support is designed to bear the weight of a higher mount. var addyd53b59933f6c3f2e8b59f1b4a6d41fa5 = 'info' + '@'; Re: Dinghy with a long shaft motor? It also decreases the boats lift and increases the time it takes for the boat to reach plane. Displacement hulled vessels like sailboats and workboats can benefit from a little more space between the hull and cavitation plate, but not much. The outboard comes with mounting holes and brackets. For over five years he has worked as a newspaper reporter and historic researcher. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". not sure that it's still used. Take a long straight edge, (long carpenter's level or long You dont have to be a mathematician to determine the correct boat transomangle. To do so, take a measurement from the very top to the very bottom of the transom in the precise center. Add the two measurements and you get 6 1/2". Cavitation plates are used on the bottom components of boats to help them operate better. priceSelector: ".price--withoutTax, span.price.price--withTax", Oftentimes you will want to adjust the outboard shaft length in order to improve the boat performance such as speed. An inch or two probably wont make a big difference, but any more than that will lead to trouble. Youll need a short shaft outboard if its 15 or less than an inch shorter. To do so, measure from the stern (back) of the boat to the midpoint of the hull on both sides. 5/rC,aQhsK@Q. It also includes attaching the right engine. 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. (function (d) { They keep water out of your prop and increase water pressure in the system. If so, send me an 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. var xmlHttp = new XMLHttpRequest(); How do you measure a transom on an outboard motor? 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. This measurement was approximately 4". Generally, short shaft outboards are 15 inches, long shaft outboards are 20 inches, and extra-long outboards are 25 inches. With the long side (22 1/2), place a carpenters square ) in opposition to the keel. of the motor off the transom If the propeller fails to ventilate, the motor is mounted to low. Most transom savers can support up to a 150HP motor, which is sufficient for most regular boats. function loadScript(script) { Place the point of a yardstick at the middle of the top of the boat transom. var ptScript = "https://cdn.paytomorrow.com/js/pt-mpe.min.js"; To achieve this, the motor itself has to be attached at the correct height. It varies between different motors and boats. This alone can outweigh the negatives when deciding to adjust the mount upwards. Or it can have an angle degree as high as 30. Outboard Motor Shaft Length - LeeRoy's Ramblings A1: Broadly speaking, the outboard motor shaft length for pontoon boat, bass boat, or other larger boats should be long shaft. 12 Small Fishing Boat Accessories to Buy Today. Knowing how this can affect the overall operation of the boat is a factor to be considered. jackplate to a point level with the top of the transom. Which Navigation Lights Does Your Boat Need? To make the yard stick long enough to measure the length of all the clubs, tape the ruler to the top. 7. 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. If your boat is newer and the manufacturer is still in business, you might also want to try to give them a call. How to Measure Transom Height For vessels with transom-mounted outboards, you can easily figure out which type of outboard you need to get. 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). mpeInit(); Wherever the outboard clamping bracket is, use this as the basis for measurement. Another important measurement is the transom angle. 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 mounting directly to a boat transom: Measure from the top of the transom down to the bottom of the hull or keel (lowest point). When the boat transom is too low, the motor could end up underwater. It is where the outboard is mounted, and some boat owners place the name of the boat. If the propeller fails to ventilate, the motor is mounted to low. Industry standards dictate that for short shaft engines the transom height should be 15. Smaller boats may use adjustable jack plates that can be changed to fit any outboard. })(); 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 will ensure the best performance. Save my name, email, and website in this browser for the next time I comment. However, you will need an understanding of how the degrees will alter the boats usability. Its still smart to measure it yourself though, just in case, the design changed over the years. You dont have to be a mathematician to determine the correct boat transom angle. The height of the boat transom dictates the size of the outboard motor. help with shaft length for a kicker - iboats Boating Forums High powered boats usually only come in long and extra-long variants. Beyond motorboats designed for large outboards, you will see outboards hanging on the sterns of everything from small canoes to large cruising sailboats. Then test the boat and adjust the height, if necessary . former editor at Boating Magazine and contributor to many national publications The performance of these boats depends on quite a lot of factors, but getting the outboard length just right is an essential first step. 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. Outboard Motor Shaft Length & HP to Boat Calculating What Is Boat Transom Height? | Gone Outdoors | Your Adventure Awaits (In the case of the faster Long shafts are 20-inches long. You also might not be able to lift the outboard out of the water entirely for storage. Engine Oil Mixing Ratio Fuel 50: Engine Oil 1. Doing this can have adverse effects. In lower mounting, the engine is set lower than the recommended standard. Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. What Is the Transom of a Boat? EXPLAINED - My Cruiser Life height (that I'm aware of); probably the most common is: The first order of business is to measure your boat for the ideal fit. Follow Westshore Marine & Leisure on Twitter! But, how do you measure it? Youll also want to pay attention when youre in shallow water because your prop will be lower than normal. This is measured by the propeller shaft being parallel to the vessels bottom. Attention: Remember to measure the outboard shaft length straight up and down instead of measuring along the transom. It also cuts into speed and fuel efficiency. There are 2 steps to help get a relatively accurate figure. You need JavaScript enabled to view it. The lowest point will likely be directly under your drain plug if youve got one. Higher mounting decisions should be left to the professionals. 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. This cookie is set by GDPR Cookie Consent plugin. This exhaust port should be about 1 inch above the water line when the boat is idling. Or measure from the main engine prop up to the water line? The transom is the flat vertical section at the rear of the boat. Small portable outboards ranging from 2 to 20 horsepower are usually sold only in short or long shaft versions. However, the motor should not be raised more than 5 inches above the standard position.