However, with the outboard shaft length too short, meaning the prop is too close to the surface, the engine is likely to ventilate and therefore slip on acceleration or lose power. The height of the boat transom dictates the size of the outboard motor. Necessary cookies are absolutely essential for the website to function properly. }) } }); })(document); If you go too short your more than likely going to cavitate and loose power. Height Measurement: Recommended Shaft Length: 14" - 17.25" 15" Shaft (Short) 17.25" - 19.5" Varies by application 19.5" - 22.5" 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. Ten years ago I bought my first boat. How to Measure Shaft Length on Outboard Motor? - TrollinMotorsGuide MarinePartsMan.com also says that V6 bass-boat engines have a 20-inch shaft. Pretty easy to figure out but like I said its crucial to pairing a motor with a boat. Measure straight down to the lowest point on the hull. Your at your local outboard dealer shopping for a new motor and the salesman hits you with the question, "short or long shaft?". Always weigh the risks of making adjustments. motor brackets To achieve this, the motor itself has to be attached at the correct height. Remember, if you use a longer outboard shaft than you need you will be increasing your draft. Attention: Remember to measure the outboard shaft length straight up and down instead of measuring along the transom. A: The short answer is Yes. So you should just measure the height of the boats transom from the center down to the lowest point of the hull, and compare transom height with the outboard shaft length numbers. 12 Small Fishing Boat Accessories to Buy Today. ensure that your measurement is accurate. Make sure that you are measuring straight up, at a 90 degree angle to This provides seaworthiness and offers maximum protection from large seas. Or measure from the main engine prop up to the water line? There are instances where a lower mount may be okay. How do you measure a transom on an outboard motor? This measurement was approximately 4". Mounting kicker motor - General Discussion Forum | In-Depth Outdoors 3 0 obj It will ensure that the outboards trim will be effective, and it will save you gas too. bracket. Take your time and understand your boat and your entire transom. 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. Should I take the raft onto the water and measure the exact distance from the top of the transom to the water line? He is a The cookies is used to store the user consent for the cookies in the category "Necessary". The average transom angle is around 14 degrees. The propellers will also have trouble reaching the water. This is simply a measurement taken from the top of the transom (top of The first step is to determine the height of your boat's transom. I would also recommend finding your maximum horsepower rating which is located on the yellow coast guard tag towards the back of your boat. Youll also want to pay attention when youre in shallow water because your prop will be lower than normal. Picking the right shaft length is mostly a factor of the transom height or the back of the boat. This would not be a good thing. if (PayTomorrow) { The point where these measurements intersect is your centerline. 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. |. AztH ^zv_ cT,E1K/rAB54| 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. Take your time and understand your boat and your entire transom. It is very versatile as it generally . See When St. Peters Basketball Games Are Today! 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. boats.com is part of the Boats Group Network. Later in the article is an image that shows you exactly where to measure. Keep these numbers in mind if you ever have a need for a new outboard motor for your boat. Add yours in the comment and Ill get back to you asap. 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. Whether you already own a boat or looking for your first watercraft we are here to service your needs. This illustration depicts four different outboard mounting height options (courtesy Mercury Marine). Most of the time, adding a hydrofoil to an outboard improves performance. disregard the "hooks" at the front of the This could also effect your travelling capabilities on the boat trailer. Long shafts are 20-inches long. Its important to note that manufacturers call their models different things. What's the best height for my boat motor? Simply start with the engine in idle, followed by trimming the motor out by one-half to full trim. Some fishing boats can handle the motor being underwater. 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. I believe 20 to 21 inches is the optimum length for a lengthy shaft. height (that I'm aware of); probably the most common is: So from there, I will try to help out by asking questions about your boat such as what type it is and the length. The cookie is used to store the user consent for the cookies in the category "Other. up to the bottom of the motor brackets, (as in #1). Two years ago, I bought a Boston Whaler to fish off the coast. The Best Way to Measure Prop to Pad | How to measure Outboard Motor Height 1855 Alpine Avenue NWGrand Rapids, MI 49504This email address is being protected from spambots. endobj This placement is not only recommended but it will give you the best performance compared to something that is too long or too short. Outboard Motor Shaft Length & HP to Boat Calculating When the boat transom is too low, the motor could end up underwater. 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. Any questions? A reverse transom that sits too high can impact the propellers of the motor and motor bracket. It is extremely important that the boater understands the significance of the transoms height. 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. Analytical cookies are used to understand how visitors interact with the website. It is where the outboard is mounted, and some boat owners place the name of the boat. All boats are different, and the motor manufacturers produce a variety of standard lengths. var xmlHttp = new XMLHttpRequest(); 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. Place the point of a yardstick at the middle of the top of the boat transom. If youre going the other way around and trying to figure out how long the shaft on your outboard is, measuring it is equally easy. 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. Determining Your Boat Transom Angle The transom angle - commonly measured in degrees - is the transom's vertical inclination. Ill also explain the difference between short and long shafts and how they vary by type of boat. clearInterval(interval); With such an important, long-term, and expensive upgrade, its never a bad idea to double-check. Step 3: Add another 10 cm (4'') to the previous calculation for the final ideal shaft length. These two measurements will give you the length of the shaft you need. 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. Measuring Motor Height - BassBoat Central h[0].appendChild(s); The pressure behind your hand dropped as you slid your hand back and forth through the water. Where Onboard a Boat is the Transom Located and More About Transom Heights A propeller operates based on the height of the transom. Allowing the propeller to pull water from underneath and push it out behind the boat. To break it down a bit more for you: Short shafts are 15-inches long. Raising the motor increases the speed of the boat while decreasing the effort needed to turn the boat. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. 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. 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}'); storeDisplayName: "Marine Parts Warehouse", maxTerm: 36, Because of the increased friction, cavitation reduces efficiency. How to Buy a Boat: Tips for a First Time Buyer, Top 10 New Fishing Boats for Under $20,000, What Type is Right for You? Having the cavitation plate a bit lower than the transom is preferable to having it too high. 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. Industry standards dictate that for short shaft engines the transom height should be 15. Measure the area of the transom directly where the engine will be mounted. Learn More About Your Boats Systems By Joining The Born Again Boating Academy! This is measured by the propeller shaft being parallel to the vessels bottom. <> You need JavaScript enabled to view it. Anything bigger than that your obviously going to need an extra long shaft. A deep Vee hull will result in a different measurement than a flatter . 7. For slower boats, its less critical to. minAmount: 300.0, It can also improve the experience of driving a faster boat. Before we start measuring the outboard shaft length, lets get it clear about whats referring to when we talk about the outboard shaft length. On the downside, a higher mount can interfere with the boaters steering capabilities. out the confusion. 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. If you said something smaller than that, thats where it can get tricky. Finding the right size is a matter of looking at what youve got and taking out the measuring tape. Owners of bass boats, RIBs, or offshore fishing boats need to get this right. 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 performance of these boats depends on quite a lot of factors, but getting the outboard length just right is an essential first step. In the past, though, it housed the officers and captain of 17th, 18th and 19th century sailing ships. 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. Add the two measurements and you get 6 1/2". resting on the transom if you had the motor all the way down on the boat mpeInit(); } document.getElementById('cloakd53b59933f6c3f2e8b59f1b4a6d41fa5').innerHTML = ''; 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. Theyre also useful if the back of your boat has a non-standard measurement. 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. 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. Repowering your boat is one of the most expensive upgrades you can make. It is extremely important that the boater understands the significance of the transom's height. former editor at Boating Magazine and contributor to many national publications On the downside, a higher mount can interfere with the boaters steering capabilities. Your goal is to measure how the outboard will sit, so start from the clamping plate and follow the centerline of the hull. 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. Any owner seeking the last bit of speed from an outboard-powered boat should grab a yard stick.