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. No one wants to have issues with a new transom or boat repairs. Read the following to get the optimal shaft length for outboard motors! 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). It is extremely important that the boater understands the significance of the transoms height. minAmount: 300.0, https://www.bornagainboating.com/Get Your Born Again Boating Clothing! Whats the best height for my boat motor? Measure from the top of the straight edge to the center of the front
brackets. It moves an outboard up and down to optimize performance and enable a boat to venture into shallower water than it might otherwise. (Any measurement given as "off the transom"
I also love helping others, which is why I created this website. According to MarinePartsMan.com, the outboard can be raised 1 inch above the standard height for every 10 miles per hour of speed the boat can attain. hulls, such as Allisons, Bullets, Strokers, etc., this measurement could
To measure the transom height, measure from the center on for transom (rear of the boat). No one wants to have issues with a new transom or boat repairs. And the rule of thumb is that you should keep the cavitation plate level with the bottom or keel of the boat. } I would ask you to go back and measure the transom of your boat. The Effects of Standard, Lower and Higher Mounting. Mounting the motor lower on the boat transom can create excessive spray, increase case drag, reduce underwater clearance, and negatively impact faster boats. It is extremely important that the boater understands the significance of the transom's height. The mounting height of an outboard motor can impact the speed and handling characteristics of the boat. the propshaft below or above the pad. 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 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. With such an important, long-term, and expensive upgrade, its never a bad idea to double-check. Propshaft in
You also might not be able to lift the outboard out of the water entirely for storage. addyd53b59933f6c3f2e8b59f1b4a6d41fa5 = addyd53b59933f6c3f2e8b59f1b4a6d41fa5 + 'vanssports' + '.' + 'com'; 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. The outboard comes with mounting holes and brackets. While this is the case there is certain saltwater motors that are extra extra long at 30 and 35 shaft. C Cheaptoon Cadet Joined Aug 4, 2010 Messages 28 Aug 24, 2010 #4 Re: Motor height on pontoon? Most of the time, adding a hydrofoil to an outboard improves performance. Each one has a totally different effect on the boats performance. Boat transomangles play a pivotal role in the flexibility of the boats trimming abilities. would be more accurate.) This measurement would be the inches of
(function (d) { The boat transom can be flat with zero degree angles. As summer approaches there will be more boaters taking to the water. At least if its too long you can raise the motor or "build up" your transom. Again, make sure that you are measuring to the flat part of the brackets;
xmlHttp.open('POST', 'https://bes.gcp.data.bigcommerce.com/nobot'); It is possible that the motor could hang low while transporting on the boat trailer causing future boat repairs. 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. If you said something smaller than that, thats where it can get tricky. If the height of the boat transom is off it can cause major issues. Finding the right size is a matter of looking at what youve got and taking out the measuring tape. With a jack plate, you can mount it exactly where you want it. The outboard comes with mounting holes and brackets. bassboat can be a bit confusing at times; hopefully this will help sort
of the motor off the transom
One of the great things about an outboard motor is how versatile it is. Measuring the shaft length can be done in various ways, but the most common way is by using a tape measure. Will Charpentier is a writer who specializes in boating and maritime subjects. d.addEventListener("DOMContentLoaded", function (e) { Extra-extra long shafts are 30-inches long. 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. Height Measurement: Recommended Shaft Length: 14" - 17.25" 15" Shaft (Short) 17.25" - 19.5" Varies by application 19.5" - 22.5" One of the main concerns is causing the engine to overheat if not enough water reaches the engine to keep it cool. The height of the boat transom dictates the size of the outboard motor. Check out the Westshore Marine & Leisure google plus page! It varies between different motors and boats. However, the motor should not be raised more than 5 inches above the standard position. It is possible that the motor could hang low while transporting on the boat trailer causing future boat repairs. This is measured by the propeller shaft being parallel to the vessels bottom. The transom is the "back wall" of your boat, the most rearward part of your hull. maxAmount: 6500.0, Tightening Torque for Engine. Of course, its always best to go with standard practices when choosing thebest boat engine. The cookie is used to store the user consent for the cookies in the category "Other. publicId: "32bf3437d1346295e03ebcf545f9c839", 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. Check out the full chart of the Mercury outboard model code and its features. For vessels with transom-mounted outboards, you can easily figure out which type of outboard you need to get. Because of the increased friction, cavitation reduces efficiency. The how to measure the shaft length of an outboard motor is a question that many people have asked. (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. Picking the right shaft length is mostly a factor of the transom height or the back of the boat. parallel with the straight edge. 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. 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. All things considered, sticking with the industry standard is best for the beginner. These cookies will be stored in your browser only with your consent. Here we will guide you in how to get the right boat transom height. If it measures 15" or with in a inch of that you will need a short shaft outboard. 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. These are vertically aligned so the boater can make adjustments. To do so, take a measurement from the very top to the very bottom of the transom in the precise center. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". It also cuts into speed and fuel efficiency. will be to the flat part; if you measure to the bottom of the brackets
The correct shaft length for your boat depends on a few factors. %
Also, how do you determine the length of an outboard transom? You can find your Mercury outboard model code on an ID plate or sticker. Shaft lengths are available in increments of 5. 7. These cookies track visitors across websites and collect information to provide customized ads. The cookie is used to store the user consent for the cookies in the category "Analytics". This illustration depicts four different outboard mounting height options (courtesy Mercury Marine). I hope this helps someone out in their search for a new or newer outboard this season. bracket. Pad to bottom of
Doing so, will put the propeller right below the boat. 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. <>
This cookie is set by GDPR Cookie Consent plugin. As with anything, there are exceptions to the rule. Step 2 requires the propeller's radius (check the user manual and then the technical drawing). They keep water out of your prop and increase water pressure in the system. Cutting the transom down is the only legal method to utilize a short shaft engine on a tall transom. However, the shaft length for smaller boats could be long or short depending on its style, speed requirement, etc. Once you know what will fit on your hull, you can fine-tune your choice based on the performance youre looking for and how you use the boat. If you go too short your more than likely going to cavitate and loose power. logoColor: "original", Place the bracket on the transom to the left of the main outboard or rudder. This provides seaworthiness and offers maximum protection from large seas. Small motors built for sailboats might come in a unique configuration with an extremely long shaft since these are mounted higher off the water. There are 2 steps to help get a relatively accurate figure. 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. Another important measurement is the transom angle. Engine Oil Mixing Ratio Fuel 50: Engine Oil 1. The motor length corresponds to the transom height of the boat, measured from the keel to gunwale at the transom. Attention: Remember to measure the outboard shaft length straight up and down instead of measuring along the transom. The motor is what powers the boat so the two go hand-in-hand. Boat Transom Heights The Beginners Guide, Buying a boat can be an exciting purchase. To sum up, there is a simple calculator of the shaft length for outboard motors: Outboard Shaft Length = Transom Height +/- Factors. var path = 'hr' + 'ef' + '='; Raising an outboard higher on the transom can reduce drag and raise top speed. On the downside, a higher mount can interfere with the boaters steering capabilities. To do so, you will want to measure at the exact center of the transom from the very top to the very bottom. 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. This will be the
My family and I used it to fish, ski (yes, you can ski behind a pontoon boat), and cruise the lakes near our home. Measure from the top of the transom to the bottom of the hull. Outboards designed for saltwater applications usually have longer shafts. Displacement hulled vessels like sailboats and workboats can benefit from a little more space between the hull and cavitation plate, but not much. ensure that your measurement is accurate. (616) 364-0666, On all contiguous US part orders over $100. If you decide to make adjustments, please consult a marine engine dealer about the boatdesign. 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. s = d.createElement("script"); 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. In step 3, add another 10 cm (4") to the previous calculation in order to develop the ideal shaft length. 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. The transom is the flat vertical section at the rear of the boat. Industry standards dictate that for short shaft engines the transom height should be 15. In the case of a dinghy or johnboat, this point may be the top of the transom. However, there may be times when a boater strays away from these recommendations. Knowing how this can affect the overall operation of the boat is a factor to be considered. 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. e-mail
Mounting the outboard a little bit lower than the standard point could avoid the possible ventilation and slip on acceleration. 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.com, 1221 Brickell Avenue, 23rd Floor, Miami, FL 33131, USA. With the long side (22 1/2), place a carpenters square ) in opposition to the keel. 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. }) } }); })(document); Small portable outboards ranging from 2 to 20 horsepower are usually sold only in short or long shaft versions. The cookies is used to store the user consent for the cookies in the category "Necessary". They operate as a planing surface, allowing your boat to climb to the top more quickly. Increased RPM and additional horsepower feed the need for speed. In the second photo, we've measure down from the top of the Detwiler
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. What Types of Documents Can be Sent to your Kindle Library? Basically, there are three main ways to measure motor
If it measures between 17 and 22, you'll want to go with a long shaft motor. resting on the transom if you had the motor all the way down on the boat
|. Measure from the top of the transom to the bottom of the hull. An outboard motor can drive just about any sort of boat with proper mounting. I live for the weekends when I can go out on the water and escape the stress of life on land. Beginning boaters should be aware of the boats measurements. If you are looking to repower, they may be able to offer some sage advice. Depending on the manufacturer, size names might change. This measurement is primarily designed for single motor propulsion. Your at your local outboard dealer shopping for a new motor and the salesman hits you with the question, "short or long shaft?". 2 0 obj
Bass boats, ski boats, or center cockpit vessels will want to double-check their measurements to get it just right. 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. 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. I believe 20 to 21 inches is the optimum length for a lengthy shaft. endobj
Figuring out how to measure motor height on a
Then, you can pick the right engine. If your outboard motor height. Tilt your motor until the bullet of the gearcase is
jackplate to a point level with the top of the transom. Typical motor lengths include the following. The average transom angle is around 14 degrees. If you have a question or need additional information. This measurement was approximately 4". There are a series of four to six holes at the top of the bracket, and the lower bolts actually fit into slots. Always weigh the risks of making adjustments. Boat hulls are designed in three basic types that range from slow displacement and semi-displacement hulls to the fastest planing hulls. The boater must also consider if the boat transomsupport is designed to bear the weight of a higher mount. This, however, is not recommended for the beginning boater. want to measure from the transom to the flat part of this bracket,
It can also improve the experience of driving a faster boat. Is my outboard long or short shaft? If you have a small boat with a 15 to 17 inch aft transom, youll most likely need a short shaft outboard. A1: Broadly speaking, the outboard motor shaft length for pontoon boat, bass boat, or other larger boats should be long shaft.