Then finally test your outboard, if the mount is perfect. <>/Metadata 127 0 R/ViewerPreferences 128 0 R>> Whether you already own a boat or looking for your first watercraft we are here to service your needs. 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. up to the bottom of the motor brackets, (as in #1). And the rule of thumb is that you should keep the cavitation plate level with the bottom or keel of the boat. Place the rulers end on the ground behind the club and let the club to rest on top of it. At least if its too long you can raise the motor or "build up" your transom. Analytical cookies are used to understand how visitors interact with the website. var h = d.getElementsByTagName("head"), As mentioned above, the operation of the propeller relies on the transom height. This cookie is set by GDPR Cookie Consent plugin. Long shafts are 20-inches long. Doing this can have adverse effects. 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. Other boats that need extra long shafts are: Read my other articles on outboard motors. It can also improve the experience of driving a faster boat. var addyd53b59933f6c3f2e8b59f1b4a6d41fa5 = 'info' + '@'; The first step is to determine the height of your boat's transom. 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. Check the literature about your model boat online, and you may be surprised to find that the number is published for you. manufacturer will recommend the outboard height according to the bracket shape and length. This distance is very important to the performance of you boat. This was the height of my 225 Yamaha on my TR21 To do so, take a measurement from the very top to the very bottom of the transom in the precise center. var ptScript = "https://cdn.paytomorrow.com/js/pt-mpe.min.js"; Since the ventilation plate & foil are burried under water it is obviously too low. Boats that use longer outboard shafts include: Measure straight down to the lowest point on the hull. Using your existing control box and gauges will save you quite a bit of money in the end. This number will likely be shorter than that for a single-engine installation since you do not necessarily measure to the point of the keel. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. Of course, its always best to go with standard practices when choosing thebest boat engine. Where Onboard a Boat is the Transom Located and More About Transom Heights A propeller operates based on the height of the transom. } Check out the Westshore Marine & Leisure google plus page! Cutting the transom down is the only legal method to utilize a short shaft engine on a tall transom. This placement is not only recommended but it will give you the best performance compared to something that is too long or too short. your motor will be higher.) The center is the point where your outboard motor is (ideally) located. straight edge on the top of the transom to "extend" it out 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 motor is what powers the boat so the two go hand-in-hand. Place the point of a yardstick at the middle of the top of the boat transom. There Many single-engine boats mount a smaller auxiliary motor for emergency use. disregard the "hooks" at the front of the What types of boat need an extra long shaft? Determining Your Boat Transom Angle The transom angle - commonly measured in degrees - is the transom's vertical inclination. This is also known as the shaft length. loadScript(ptScript); Outboard motors can be fitted to a variety of boats, so manufacturers have standardized their engines to go on virtually anything. The distance between the ends of a transom is measured in inches. former editor at Boating Magazine and contributor to many national publications Later in the article is an image that shows you exactly where to measure. For example, you can have the Mercury outboard shaft length by model code. If your boat planes, pay extra attention to getting the shaft length as close to perfect as possible. want to measure from the transom to the flat part of this bracket, But opting out of some of these cookies may affect your browsing experience. 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. If you have a question or need additional information. When the boattransom is too low, the motor could end up underwater. Outboards designed for saltwater applications usually have longer shafts. Another important measurement is the transom angle. Always weigh the risks of making adjustments. Before we start measuring the outboard shaft length, lets get it clear about whats referring to when we talk about the outboard shaft length. 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. Smaller inflatables and dinghies needshort shaft motors, whilst bigger boats require long or, in some circumstances, extreme long shaft versions. I would also recommend finding your maximum horsepower rating which is located on the yellow coast guard tag towards the back of your boat. Because of the increased friction, cavitation reduces efficiency. mpeInit(); However, the motor should not be raised more than 5 inches above the standard position. 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. Why wont Touch ID be under the screen in the iPhone 15 and iPhone 16? A: The short answer is Yes. However, you will need an understanding of how the degrees will alter the boats usability. 3 0 obj However, there may be times when a boater strays away from these recommendations. The shaft length for outboard motors has nothing to do with the water line. 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. With it comes a lot of responsibility and new things to learn includingboat maintenanceand boat basics. If you decide to make some custom adjustments we have theexperience and know-howto make it happen. This will keep the prop in the water when the boat pitches in waves, or hobby-horses. This exhaust port should be about 1 inch above the water line when the boat is idling. 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. s = d.createElement("script"); (We wont go into name-calling here, but the actual term for the cavitation plate is an anti-ventilation plate.) the propshaft below or above the pad. } He is a The pros and cons of properly . The first order of business is to measure your boat for the ideal fit. jackplate to a point level with the top of the transom. Follow Westshore Marine & Leisure on Wordpress! With a jack plate, you can mount it exactly where you want it. var h = d.getElementsByTagName("head"), For vessels with transom-mounted outboards, you can easily figure out which type of outboard you need to get. If it measures between 17 and 22, you'll want to go with a long shaft motor. The height of the boat transom dictates the size of the outboard motor. You must be still in the blue about that matter. While this is the case there is certain saltwater motors that are extra extra long at 30 and 35 shaft. All rights reserved. This, however, is not recommended for the beginning boater. Boat transom angles play a pivotal role in the flexibility of the boats trimming abilities. s.setAttribute("rel", "stylesheet"); Recommended Engine Oil 2-Stroke Outboard Motor Oil. The outboard comes with mounting holes and brackets. There is a simple test to see if your outboard motor is set at the best height. Your email address will not be published. Other boats that need long shafts are. With the motor trimmed so that the propshaft is parallel to the keel, the anti-ventilation plate should be just about even with your straight edge, and thus even with the boat bottom at the keel. (3) Move horizontally across the chart until you hit the graph curve. Attention: Remember to measure the outboard shaft length straight up and down instead of measuring along the transom. A: The answer varies by boat, but here are some rules of thumb for matching a short shaft outboard to your boat. % For really big boats, the biggest and baddest six- or eight-cylinder outboards can have extra-extra long shafts up to 30 inches. Its where the outboard motor is attached, and its also where some boat owners put the boats name. Small portable outboards ranging from 2 to 20 horsepower are usually sold only in short or long shaft versions. Simply start with the engine in idle, followed bytrimming the motor out by one-half to full trim. 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. 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. 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. Beginning boaters should be aware of the boats measurements. Remember, if you use a longer outboard shaft than you need you will be increasing your draft. Trimming in, trimming down, and trimming out are all terms that a beginning boater should learn. Attention: Remember to measure the outboard shaft length straight up and down instead of measuring along the transom. A transom saver, which can change the spacing between the lower unit and the trailer, negates some of the support. As summer approaches there will be more boaters taking to the water. A long shaft engine requires a height of 20 and extra-long shaft engines will need a transom height of 25. straight edge from the center of the pad, but this time you're measuring Next, measure from your centerline to where the outboard will be mounted on each side. Anything bigger than that your obviously going to need an extra long shaft. By clicking Accept, you consent to the use of ALL the cookies. Make sure that you are measuring straight up, at a 90 degree angle to Thats it. This allows the engine to idle without the flow of the exhaust being restricted. storeDisplayName: "Marine Parts Warehouse", 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. It will ensure that the outboards trim will be effective, and it will save you gas too. There are a series of four to six holes at the top of the bracket, and the lower bolts actually fit into slots. There are also specialty motor shaft lengths. boats.com, 1221 Brickell Avenue, 23rd Floor, Miami, FL 33131, USA. mpeSelector: ".pt-mpe", You can use a longer shaft than recommended and your boat will work fine. Smaller boats may use adjustable jack plates that can be changed to fit any outboard. will be to the flat part; if you measure to the bottom of the brackets This alone can outweigh the negatives when deciding to adjust the mount upwards. 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. var xmlHttp = new XMLHttpRequest(); Triton. The average transom angle is around 14 degrees. These allow the mounting of a standard length outboard behind the transom. brackets. https://www.bornagainboating.com/Get Your Born Again Boating Clothing! 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. (function (d) { Depending on the manufacturer, size names might change. Necessary cookies are absolutely essential for the website to function properly. This also means it can affect the safety of the boat. This restriction includes most fishing boats and longer sailboats. 12 Small Fishing Boat Accessories to Buy Today. if (PayTomorrow) { Save my name, email, and website in this browser for the next time I comment. The motor is what powers the boat so the two go hand-in-hand. Is my outboard long or short shaft? Thats a fairly simple list of symptoms, but if your motor is too low, youll probably notice at least one of them. Engine Oil Type Genuine or Recommended 2str Engine Oil. s.setAttribute("href", "https://cdn.paytomorrow.com/css/pt-mpe.min.css"); xmlHttp.setRequestHeader('Content-Type', 'application/json'); We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. 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. Buying a boat can be an exciting purchase. Many boat transoms are modified to use a different length of outboard by using a bracket. trimming the motor out by one-half to full trim. To measure the transom height, measure from the center on for transom (rear of the boat). | Sitemap, The Marine Parts Warehouse Outboard Museum, OBR Powerhead / Shortblock Warranty Claim Form, Remanufactured vs. hulls, such as Allisons, Bullets, Strokers, etc., this measurement could Boat Transom Heights The Beginners Guide, Buying a boat can be an exciting purchase. This is simply a measurement taken from the top of the transom (top of gtag('js', new Date()); Youll also want to pay attention when youre in shallow water because your prop will be lower than normal. 2019s List of the Best Recreational Pontoon Boats for Sale. 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. It is unsafe to have the engine block too close to the water on a low transom. Follow Westshore Marine & Leisure on Twitter! All rights reserved. If measuring an existing outboard: Measure from the inside top of mounting bracket down to anti-cavitation plate above propeller (this is the largest plate/fin directly above the propeller). (Putting a Most transom savers can support up to a 150HP motor, which is sufficient for most regular boats. The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. Be sure to measure carefully and research thoroughly before diving in. Having the cavitation plate too low will cause excess drag and reduced performance at high speeds. These two measurements will give you the length of the shaft you need.