However, there may be times when a boater strays away from these recommendations. Knowing the width, height and depth of your transom allows you to make several important decisions when selecting or purchasing a new outboard. For vessels with transom-mounted outboards, you can easily figure out which type of outboard you need to get. Also, how do you determine the length of an outboard transom? relation to pad
Picking the right shaft length for your outboard is an essential step in getting the best performance from your boat. 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. Follow Westshore Marine & Leisure on Wordpress! Which Navigation Lights Does Your Boat Need? Make sure that you are measuring straight up, at a 90 degree angle to
Some fishing boats can handle the motor being underwater. Doing so, will put the propeller right below the boat. 4 0 obj
How Transom Height Is Measured Boat Transom Heights The Beginners Guide, Buying a boat can be an exciting purchase. mpeSelector: ".pt-mpe", 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. 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. 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). Beginning boaters should be aware of the boats measurements. <>
If you are looking to repower, they may be able to offer some sage advice. This cookie is set by GDPR Cookie Consent plugin. center of the propshaft. 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. <>/ExtGState<>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 595.2 841.8] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>>
To do so, take a measurement from the very top to the very bottom of the transom in the precise center. 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). In the past, though, it housed the officers and captain of 17th, 18th and 19th century sailing ships. For example, you can have the Mercury outboard shaft length by model code. These cookies ensure basic functionalities and security features of the website, anonymously. There are instances where a lower mount may be okay. } This, however, is not recommended for the beginning boater. The cookie is used to store the user consent for the cookies in the category "Analytics". The average transom angle is around 14 degrees. However, there may be times when a boater strays away from these recommendations. This measurement was approximately 4". Lastly, knowing the year of your motor and what style of controls you have (side mount, concealed side mount, or binnacle) is also a plus because it will tell the dealer if your current controls are compatible with the motor you are purchasing. Bass boats, ski boats, or center cockpit vessels will want to double-check their measurements to get it just right. Here we will guide you in how to get the right boat transom height. To do so, measure from the stern (back) of the boat to the midpoint of the hull on both sides. 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. This is a measurement that has been used for BassCats, I'm
However, the motor should not be raised more than 5 inches above the standard position. Add the two measurements and you get 6 1/2". Charles Plueddeman is Boats.com's outboard, trailer, and PWC expert. Generally, the anti-ventilation plate on most engines is aligned with the bottom of the vessel. Long shafts are 20-inches long. This distance is very important to the performance of you boat. If your boat planes, pay extra attention to getting the shaft length as close to perfect as possible. Youll also want to pay attention when youre in shallow water because your prop will be lower than normal. Place the rulers end on the ground behind the club and let the club to rest on top of it. resting on the transom if you had the motor all the way down on the boat
Why wont Touch ID be under the screen in the iPhone 15 and iPhone 16? (Putting a
The lowest point will likely be directly under your drain plug if youve got one. The outboard comes with mounting holes and brackets. straight edge on the top of the transom to "extend" it out
The vertical distance between the interior of the clamp and the cavitation plate is the shaft length specified by the outboard manufacturer. 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. When you measure the width of the stern, mark the center with a grease pencil. 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. 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. The propellers will also have trouble reaching the water. To make the yard stick long enough to measure the length of all the clubs, tape the ruler to the top. It also cuts into speed and fuel efficiency. The engine must be linked to the transom at the proper height for a propeller to best meet specific boating demands. Boaters who consider going with a higher mount can see increased speeds. The prop will be in cleaner, harder water as it advances farther aft, making it more efficient. Outboard motors can be fitted to a variety of boats, so manufacturers have standardized their engines to go on virtually anything. With this in mind, how can I determine if my outboard has a short or long shaft? If it measures anywhere from 17" to around 22", then your going to want to go with a long shaft motor. All rights reserved. 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.
All things considered, sticking with the industry standard is best for the beginner. You can find your Mercury outboard model code on an ID plate or sticker. Commonly, the transom angle ranges from 0-30 degrees, with the average transom angle set at 14 degrees. An outboard motor can drive just about any sort of boat with proper mounting. This is handy if youre shopping for second-hand outboards or looking to sell the one that came with your boat. a Detwiler manual jackplate. Measure the area of the transom directly where the engine will be mounted. Increased RPM and additional horsepower feed the need for speed. A: The answer varies by boat, but here are some rules of thumb for matching a short shaft outboard to your boat. Be sure to measure carefully and research thoroughly before diving in. It is extremely important that the boater understands the significance of the transom's height. Buying a boat can be an exciting purchase. var BCData = {"csrf_token":"d7ecb6b56891bb66aee12dbc01a80162b3ed582c1acbe30f16fc9f1b2abc362f"}; endobj
High powered boats usually only come in long and extra-long variants. Your email address will not be published. This is the dimension you'll need to know when deciding between a short shaft, long shaft or extra long shaft for your outboard motor. Small portable outboards ranging from 2 to 20 horsepower are usually sold only in short or long shaft versions. When fighting waves from the stern, a 20-inch transom is considerably safer. endobj
It is where the outboard is mounted, and some boat owners place the name of the boat. As a yacht designer and boater, I prefer longer shafts. You can use a longer shaft than recommended and your boat will work fine. I would ask you to go back and measure the transom of your boat. Keep these numbers in mind if you ever have a need for a new outboard motor for your boat. Top 10 Choices for Boaters, Mercury Introduces 600HP V12 Verado Outboard Engine, The Outboard Expert: Tohatsu Propane Outboard Engine. Two years ago, I bought a Boston Whaler to fish off the coast. Now that you have a better understanding of boat transom heights its time to take out the ruler and get the perfect measurements. motor brackets
Some fishing boats can handle the motor being underwater. 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. Theyre also useful if the back of your boat has a non-standard measurement. This placement is not only recommended but it will give you the best performance compared to something that is too long or too short. Picking the right shaft length is mostly a factor of the transom height or the back of the boat. parallel with the straight edge. What Kind of Fuel Does Your Marine Engine Need? s.setAttribute("href", "https://cdn.paytomorrow.com/css/pt-mpe.min.css"); At least if its too long you can raise the motor or "build up" your transom. This cookie is set by GDPR Cookie Consent plugin. It moves an outboard up and down to optimize performance and enable a boat to venture into shallower water than it might otherwise. 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. One of the factors in determining the height of the outboard is the placement of the exhaust port on the lower unit of the outboard engine. Other boats that need long shafts are. These cookies track visitors across websites and collect information to provide customized ads. With it comes a lot of responsibility and new things to learn includingboat maintenanceand boat basics. Industry standards dictate that for short shaft engines the transom height should be 15. Well, raising the outboard motor can be an easy task for you. So how to measure outboard shaft length? steel ruler, etc. A: The short answer is Yes. The cookie is used to store the user consent for the cookies in the category "Other. Among them will be first-timers or those who have recently purchased their boats. The distance between the ends of a transom is measured in inches. Then adjust the motor in a higher hole with a flat head screwdriver. This, however, is not recommended for the beginning boater. How do you measure a transom on an outboard motor? In the photo above, we've measured from the motor bracket to the top of
These cookies will be stored in your browser only with your consent. But opting out of some of these cookies may affect your browsing experience. Thats it. Here are several situations on how you should adjust the outboard shaft length: Mounting the outboard a little bit higher than the standard point could reduce drag, improve RPM at full throttle, and therefore improve speed and make it easier for the boat to get on plane. To achieve this, the motor itself has to be attached at the correct height. Before we start measuring the outboard shaft length, lets get it clear about whats referring to when we talk about the outboard shaft length. If you decide to make some custom adjustments we have theexperience and know-howto make it happen. Place the bracket on the transom to the left of the main outboard or rudder. Some outboards have a serial number that tells you which shaft length to go for. This is also known as the shaft length. Safely but briskly accelerate. measuring; you may have to "extend" the flat part of the
and I'll explain it better, (or point you to someone that can help. Attention: Remember to measure the outboard shaft length straight up and down instead of measuring along the transom. Height Measurement: Recommended Shaft Length: 14" - 17.25" 15" Shaft (Short) 17.25" - 19.5" Varies by application 19.5" - 22.5" To achieve this, the motor itself has to be attached at the correct height. Oftentimes you will want to adjust the outboard shaft length in order to improve the boat performance such as speed. Doing this can have adverse effects. var h = d.getElementsByTagName("head"), By clicking Accept, you consent to the use of ALL the cookies. Most transom savers can support up to a 150HP motor, which is sufficient for most regular boats. So from there, I will try to help out by asking questions about your boat such as what type it is and the length. There are a series of four to six holes at the top of the bracket, and the lower bolts actually fit into slots. 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. 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. 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. 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. This could also effect your travelling capabilities on the boat trailer. (Any measurement given as "off the transom"
If your outboard motor height. As with anything, there are exceptions to the rule. 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? (1) Multiply the overall length of your boat (in feet) by it's widest beam at the stern (excluding any Fins and or Shear) (2) Locate that value on the left hand vertical column of the chart below. 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. When mounting the engine, you want the cavitation plate to be 1 above the boat bottom for every 12 away from the transom. Read the measurement on the transoms bottom. 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. Simply start with the engine in idle, followed by trimming the motor out by one-half to full trim. This alone can outweigh the negatives when deciding to adjust the mount upwards. The pros and cons of properly . function mpeInit() { maxAmount: 6500.0, I mean, who wants to purchase something as expensive as an outboard to only realize you bought the wrong one. If the height of the boat transom is off it can cause major issues. Check out the Westshore Marine & Leisure google plus page! 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. displayMicroOffers: false, Boats with more engine power and weight require longer shaft outboards for better balance. 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. Beefier jack plates can be fitted should a boater be looking to mount an outboard with a shorter shaft than their transom demands. Depending on the manufacturer, size names might change. 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. var interval = setInterval(function () { How the outboard will sit on the back of the boat depends on how the transom is designed. h[0].appendChild(s); What is the Virtual Sundance Film Festival? AztH
^zv_ cT,E1K/rAB54| When the boat transom is too low, the motor could end up underwater. var xmlHttp = new XMLHttpRequest(); out the confusion. Outboard Motor Shaft Length: How do I measure? s.setAttribute("type", "text/javascript"); ), and place it on the bottom of the pad in the center. A reversetransom that sits too high can impact the propellers of the motor and motor bracket. Some boats are equipped with transom-hung outboards while others have a bracket. What is Transom Height? These are vertically aligned so the boater can make adjustments. Having the cavitation plate a bit lower than the transom is preferable to having it too high. height (that I'm aware of); probably the most common is:
August 9/08). So how to determine the outboard shaft length? The height of the boat transom dictates the size of the outboard motor. On the downside, a higher mount can interfere with the boaters steering capabilities. Pad to bottom of
An inch or two probably wont make a big difference, but any more than that will lead to trouble. jackplate to a point level with the top of the transom. 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. (127 mm). There are 2 steps to help get a relatively accurate figure. 12 Small Fishing Boat Accessories to Buy Today. Mounting the outboard motor in accordance with the industry standards is important. 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. There is a simple test to see if your outboard motor is set at the best height. C Cheaptoon Cadet Joined Aug 4, 2010 Messages 28 Aug 24, 2010 #4 Re: Motor height on pontoon? Many single-engine boats mount a smaller auxiliary motor for emergency use. Wherever the outboard clamping bracket is, use this as the basis for measurement. Generally, the anti-ventilation plate on most engines is aligned with the bottom of the vessel. Look at the part of your motor that would be
This is measured by the propeller shaft being parallel to the vessels bottom. straight edge from the center of the pad, but this time you're measuring
But in many cases, its a little more complicated than that alone. Other factors to consider when determining the mounting height of an outboard are related to performance. %PDF-1.7
Happy boating! You also might not be able to lift the outboard out of the water entirely for storage. Gear case sits just below or at the hull depth due to the deep v. If youre looking for a bracket that can handle motors of up to 10/15 horsepower, go no further. Step 4. If you said something smaller than that, thats where it can get tricky. trimming the motor out by one-half to full trim. However, the shaft length for smaller boats could be long or short depending on its style, speed requirement, etc. }) } }); })(document); One of the main concerns is causing the engine to overheat if not enough water reaches the engine to keep it cool. Smaller 12-14 foot boats can require either a short or long shaft outboard depending on the style of the boat and the brand. This restriction includes most fishing boats and longer sailboats. However, youll notice a little increase in drag and a decrease in top-end performance. In the second photo, we've measure down from the top of the Detwiler
He is also a certified marine technician and the author of a popular text on writing local history. Smaller inflatables and dinghies needshort shaft motors, whilst bigger boats require long or, in some circumstances, extreme long shaft versions. It is possible that the motor could hang low while transporting on the boat trailer causing future boat repairs. I live for the weekends when I can go out on the water and escape the stress of life on land. 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. from the transom. Your goal is to measure how the outboard will sit, so start from the clamping plate and follow the centerline of the hull. want to measure from the transom to the flat part of this bracket,
You will also risk hitting bottom or submerge objects more frequently such as rocks or logs. 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. Add yours in the comment and Ill get back to you asap. How to Measure Transom Height For vessels with transom-mounted outboards, you can easily figure out which type of outboard you need to get. | Sitemap, The Marine Parts Warehouse Outboard Museum, OBR Powerhead / Shortblock Warranty Claim Form, Remanufactured vs. To do so, you will want to measure at the exact center of the transom from the very top to the very bottom. The standard installation of an outboard has the top of the transom of the boat at the same level as the bottom of the motor portion of the outboard. What types of boat need an extra long shaft? For over five years he has worked as a newspaper reporter and historic researcher. Cutting the transom down is the only legal method to utilize a short shaft engine on a tall transom. Its where the outboard motor is attached, and its also where some boat owners put the boats name. function gtag(){dataLayer.push(arguments);} It can also improve the experience of driving a faster boat. 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. While this is the case there is certain saltwater motors that are extra extra long at 30 and 35 shaft. These allow the mounting of a standard length outboard behind the transom. Each one has a totally different effect on the boats performance. the aluminum plate on top of the transom), to the bottom of the motor
If it measures 15" or with in a inch of that you will need a short shaft outboard. will be to the flat part; if you measure to the bottom of the brackets
This is simply a measurement taken from the top of the transom (top of
Where Onboard a Boat is the Transom Located and More About Transom Heights A propeller operates based on the height of the transom. publicId: "32bf3437d1346295e03ebcf545f9c839", All things considered, sticking with the industry standard is best for the beginner. var addyd53b59933f6c3f2e8b59f1b4a6d41fa5 = 'info' + '@'; window.dataLayer = window.dataLayer || []; As a result, the issue is whether my boat need a short shaft or long shaft motor. disregard the "hooks" at the front of the
Or it can have an angle degree as high as 30. Beginning boaters should be aware of the boats measurements. (3) Move horizontally across the chart until you hit the graph curve. This illustration depicts four different outboard mounting height options (courtesy Mercury Marine). Industry standards dictate that for short shaft engines the transom height should be 15. Allowing the propeller to pull water from underneath and push it out behind the boat. Another important measurement is the transom angle.
Although the longer outboard shaft length can lead to lower speed and more drag, the boat can push a heavier load. It is where the outboard is mounted, and some boat owners place the name of the boat. 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. Small motors built for sailboats might come in a unique configuration with an extremely long shaft since these are mounted higher off the water. Typical motor lengths include the following. On the downside, a higher mount can interfere with the boaters steering capabilities. This cookie is set by GDPR Cookie Consent plugin. The standard shaft length for most outboard engines less than 125 horsepower is 20 inches. maxTerm: 36, Each one has a totally different effect on the boats performance. actually have the propshaft above the pad.). To do so, take a measurement from the very top to the very bottom of the transom in the precise center. Lubrication System Engine Oil Mixed Gasoline. Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. Whats the best height for my boat motor? This is the dimension you'll need when selecting a width for your outboard motor's mounting bracket. since 1986. The transom angle is the vertical incline of the transom and is measured in degrees. As with anything, there are exceptions to the rule. I hope this helps someone out in their search for a new or newer outboard this season. In the case of a larger offshore boat, it may be to the top of a cutout on the . Your goal is to measure how the outboard will sit, so start from the clamping plate and follow the centerline of the hull. There are instances where a lower mount may be okay. You need JavaScript enabled to view it. As mentioned above, the operation of the propeller relies on the transom height. 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. While this is the case there is certain saltwater motors that are extra extra long at 30. If the propeller fails to ventilate, the motor is mounted to low. The height of the boat transom dictates the size of the outboard motor. Extra-long shafts are 25-inches long. Mounting the outboard a little bit lower than the standard point could avoid the possible ventilation and slip on acceleration. 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.