Learn More About Your Boats Systems By Joining The Born Again Boating Academy! There is a simple test to see if your outboard motor is set at the best height.
Recommended Engine Oil 2-Stroke Outboard Motor Oil. Also, the boat will be more likely to hit bottom or submerge objects such as rocks or logs. "brackets". This measurement is primarily designed for single motor propulsion. As you can see, the measurement is about 2 1/2". It can also improve the experience of driving a faster boat. If you have a question or need additional information,contact ustoday. Measuring the shaft length can be done in various ways, but the most common way is by using a tape measure. Step 2 requires the propeller's radius (check the user manual and then the technical drawing). manufacturer will recommend the outboard height according to the bracket shape and length. center of the propshaft. Doing this can have adverse effects. 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. Now that you have a better understanding of boat transom heights its time to take out the ruler and get the perfect measurements. clearInterval(interval); It doesnt matter if you have a fiberglass boat, bay boat, big or small boat. | Sitemap, The Marine Parts Warehouse Outboard Museum, OBR Powerhead / Shortblock Warranty Claim Form, Remanufactured vs. It varies between different motors and boats. Your email address will not be published. Not to measure boat speed, but to gauge the mounting height of the outboard motor on the boat transom. Read the following to get the optimal shaft length for outboard motors! 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. However, there may be times when a boater strays away from these recommendations. 1 0 obj
This cookie is set by GDPR Cookie Consent plugin. Add the two measurements and you get 6 1/2". 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". Simply start with the engine in idle, followed by, If you decide to make some custom adjustments we have the. The faster your boat, the more critical it is to get the sizing just right. Check the literature about your model boat online, and you may be surprised to find that the number is published for you. This cookie is set by GDPR Cookie Consent plugin. This is handy if youre shopping for second-hand outboards or looking to sell the one that came with your boat. Raising an outboard higher on the transom can reduce drag and raise top speed. If you have a question or need additional information. Gear case sits just below or at the hull depth due to the deep v. How do you measure a transom on an outboard motor? Place the point of a yardstick at the middle of the top of the boat transom. Depending on the manufacturer, size names might change. This is a measurement that has been used for BassCats, I'm
Mounting the motor lower on the boat transomcan createexcessive spray, increase case drag, reduce underwater clearance, and negatively impact faster boats. You can order an outboard in lengths ranging from 15 inches to 30 inches, depending on its power output and possible uses. You need JavaScript enabled to view it. If you have a small boat with a 15 to 17 inch aft transom, youll most likely need a short shaft outboard. As a dealer I run into this situation from time to time, which is fine but getting the right length outboard for your boat is crucial. If your outboard motor height. disregard the downward pointing "hooks" at the front of the
Workboats, sailboats, and displacement-hulled boats fall into this category. former editor at Boating Magazine and contributor to many national publications Problems with getting the ventilation plate too low include slower hole-shot and lower top-end speeds. Thats a fairly simple list of symptoms, but if your motor is too low, youll probably notice at least one of them. However, the motor should not be raised more than 5 inches above the standard position. The boater must also consider if the boat transom support is designed to bear the weight of a higher mount. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. I show you how to consistently measure your prop to pad height. want to measure from the transom to the flat part of this bracket,
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. Height Measurement: Recommended Shaft Length: 14" - 17.25" 15" Shaft (Short) 17.25" - 19.5" Varies by application 19.5" - 22.5" The lowest point will likely be directly under your drain plug if youve got one. Brackets are also handy for boats that do not have flat transoms, like canoe-stern sailboats or fan-tailed motor vessels. 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. Each one has a totally different effect on the boats performance. For boats equipped with a bracket, calculate the same measurement but based on the bracket and not 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. 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. I believe 20 to 21 inches is the optimum length for a lengthy shaft. It also cuts into speed and fuel efficiency. 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). Place the bracket on the transom to the left of the main outboard or rudder. Many single-engine boats mount a smaller auxiliary motor for emergency use. As with anything, there are exceptions to the rule. Take your time and understand your boat and your entire transom. Knowing the width, height and depth of your transom allows you to make several important decisions when selecting or purchasing a new outboard. 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. This would not be a good thing. Another important measurement is the transom angle. I would ask you to go back and measure the transom of your boat. The boat transom can be flat with zero degree angles. Shaft lengths are available in increments of 5. To sum up, there is a simple calculator of the shaft length for outboard motors: Outboard Shaft Length = Transom Height +/- Factors. Measure straight down to the lowest point on the hull. boats.com, 1221 Brickell Avenue, 23rd Floor, Miami, FL 33131, USA. loadScript(ptScript); It can also improve the experience of driving a faster boat. Boat transomangles play a pivotal role in the flexibility of the boats trimming abilities. var h = d.getElementsByTagName("head"), In the case of a dinghy or johnboat, this point may be the top of the transom. If you decide to make some custom adjustments we have theexperience and know-howto make it happen. Propshaft in
Then adjust the motor in a higher hole with a flat head screwdriver. Or measure from the main engine prop up to the water line? 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. Other boats that need long shafts are. bracket forward with a straight edge to where you can then measure up
Mounting the motor lower on the boat transom can create excessive spray, increase case drag, reduce underwater clearance, and negatively impact faster boats. At least if its too long you can raise the motor or "build up" your transom. The vertical distance between the interior of the clamp and the cavitation plate is the shaft length specified by the outboard manufacturer. stream
When you measure the width of the stern, mark the center with a grease pencil. (In the case of the faster
Small motors built for sailboats might come in a unique configuration with an extremely long shaft since these are mounted higher off the water. When mounting the engine, you want the cavitation plate to be 1 above the boat bottom for every 12 away from the transom. What Types of Documents Can be Sent to your Kindle Library? Most of the standard engined boats it takes shafts that are 15-30inches long. The outboard comes with mounting holes and brackets. Top 10 Choices for Boaters, Mercury Introduces 600HP V12 Verado Outboard Engine, The Outboard Expert: Tohatsu Propane Outboard Engine. So from there, I will try to help out by asking questions about your boat such as what type it is and the length. storeDisplayName: "Marine Parts Warehouse", Two years ago, I bought a Boston Whaler to fish off the coast. https:/. How high exactly do you have to raise the transom?-. The first order of business is to measure your boat for the ideal fit. The propellers will also have trouble reaching the water. 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. Outboards designed for saltwater applications usually have longer shafts. trimming the motor out by one-half to full trim. My family and I used it to fish, ski (yes, you can ski behind a pontoon boat), and cruise the lakes near our home. It will ensure that the outboards trim will be effective, and it will save you gas too. 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. mpeSelector: ".pt-mpe", bracket. To do so, you will want to measure at the exact center of the transom from the very top to the very bottom. debugMode: false, Doing so, will put the propeller right below the boat. endobj
Youll need a short shaft outboard if its 15 or less than an inch shorter. In the case of a larger offshore boat, it may be to the top of a cutout on the . Sluggish speeds, poor handling, heavy spray, porpoising, or even water pushing up into the cowling are all signs that an outboard is set too low. Raising the motor increases the speed of the boat while decreasing the effort needed to turn the boat. If you have an outboard motor, the distance from one end to another will be found on the side or on a label near its bottom. 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. The pressure behind your hand dropped as you slid your hand back and forth through the water. 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. 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. You can use a longer shaft than recommended and your boat will work fine. Beyond motorboats designed for large outboards, you will see outboards hanging on the sterns of everything from small canoes to large cruising sailboats. Since the ventilation plate & foil are burried under water it is obviously too low. :$I>M W$h"%U_yzIb?]NHg_G|r@nX eTf."SQ With such an important, long-term, and expensive upgrade, its never a bad idea to double-check. (Any measurement given as "off the transom"
Say the 20 shaft is a long shaft length for gas engines, but it is a short shaft length for electric outboard motors. The amount of degrees the transom leans back from vertical is known as the transom angle. The average transom angle is around 14 degrees. Boat transom angles play a pivotal role in the flexibility of the boats trimming abilities. With it comes a lot of responsibility and new things to learn including boat maintenance and boat basics. Your goal is to measure how the outboard will sit, so start from the clamping plate and follow the centerline of the hull. 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. A long shaft engine requires a height of 20 and extra-long shaft engines will need a transom height of 25. These cookies ensure basic functionalities and security features of the website, anonymously. Small portable outboards ranging from 2 to 20 horsepower are usually sold only in short or long shaft versions. your motor will be higher.) The transom is the rear wall of the boat where the outboard engine is mounted in the middle. resting on the transom if you had the motor all the way down on the boat
With this in mind, how can I determine if my outboard has a short or long shaft? Generally, short shaft outboards are 15 inches, long shaft outboards are 20 inches, and extra-long outboards are 25 inches. steel ruler, etc. 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. This alone can outweigh the negatives when deciding to adjust the mount upwards. Whether your on a pontoon boat, fishing boat, or speedboat boating is always one of the best times you can have. 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. This allows the engine to idle without the flow of the exhaust being restricted. With the outboard shaft length too long, meaning the prop is too deep in the water, the engine wont be as efficient, and the fuel burn is high. 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? No one wants to have issues with a new transom or boat repairs. If you said something smaller than that, thats where it can get tricky. 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. The transom is the back of the boat where the motor is hung. minAmount: 300.0, Buying a boat can be an exciting purchase. Before we get started lets see what a boat transom is and what it does. 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. the propshaft below or above the pad. Of course, its always best to go with standard practices when choosing thebest boat engine.