Take your time and understand your boat and your entire transom. The clamp bracket is designed so that the engine's mounting height on the transom can be adjusted higher than standard. For example, you can have the Mercury outboard shaft length by model code. 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. Top 10 Choices for Boaters, Mercury Introduces 600HP V12 Verado Outboard Engine, The Outboard Expert: Tohatsu Propane Outboard Engine. Doing so, will put the propeller right below the boat. The boat transom can be flat with zero degree angles. The outboard comes with mounting holes and brackets. Commonly, the transom angle ranges from 0-30 degrees, with the average transom angle set at 14 degrees. e-mail
August 9/08). Not to measure boat speed, but to gauge the mounting height of the outboard motor on the boat transom. It doesnt matter if you have a fiberglass boat, bay boat, big or small boat. I would ask you to go back and measure the transom of your boat. Most of the standard engined boats it takes shafts that are 15-30inches long. (In the case of the faster
Buying a boat can be an exciting purchase. This email address is being protected from spambots. C Cheaptoon Cadet Joined Aug 4, 2010 Messages 28 Aug 24, 2010 #4 Re: Motor height on pontoon? A: The short answer is Yes. There are instances where a lower mount may be okay. A big NO. So from there, I will try to help out by asking questions about your boat such as what type it is and the length. This is somewhat similar to #2, in that you are again measuring with a
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). Since the ventilation plate & foil are burried under water it is obviously too low. measuring; you may have to "extend" the flat part of the
2019s List of the Best Recreational Pontoon Boats for Sale. You can order an outboard in lengths ranging from 15 inches to 30 inches, depending on its power output and possible uses. What Kind of Fuel Does Your Marine Engine Need? displayPrimeOffers: true, Setting Height of Outboard Motor - YouTube mpeInit(); help with shaft length for a kicker - iboats Boating Forums This allows the engine to idle without the flow of the exhaust being restricted. Each one has a totally different effect on the boats performance. This website uses cookies to improve your experience while you navigate through the website. This measurement was approximately 4". This also means it can affect the safety of the boat. What Is Boat Transom Height? | Gone Outdoors | Your Adventure Awaits Place the bracket on the transom to the left of the main outboard or rudder. 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. since 1986. To do so, measure from the stern (back) of the boat to the midpoint of the hull on both sides. Keep these numbers in mind if you ever have a need for a new outboard motor for your boat. Measuring Motor Height - BassBoat Central You also have the option to opt-out of these cookies. These two measurements will give you the length of the shaft you need. Lubrication System Engine Oil Mixed Gasoline. Here we look at the effects of standard, lower and higher mounting. of the motor off the transom
var h = d.getElementsByTagName("head"), and I'll explain it better, (or point you to someone that can help. enableMoreInfoLink: true, 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. Figuring out how to measure motor height on a
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#1: Height
Raising an outboard higher on the transom can reduce drag and raise top speed. Well, raising the outboard motor can be an easy task for you. What Types of Documents Can be Sent to your Kindle Library? What Is a Transom? Where Onboard a Boat is It Located? Always weigh the risks of making adjustments. It is extremely important that the boater understands the significance of the transoms height. There are 2 steps to help get a relatively accurate figure. Yamaha Outboard Motors: How To Measure Leg Length d.addEventListener("DOMContentLoaded", function (e) { He is a However, the motor should not be raised more than 5 inches above the standard position. Your at your local outboard dealer shopping for a new motor and the salesman hits you with the question, "short or long shaft?". How Transom Height Is Measured displayMicroOffers: false, The cavitation plate is the horizontal surface of the lower unit immediately above the propeller. Check out the Westshore Marine & Leisure Youtube page! Typical motor lengths include the following. Necessary cookies are absolutely essential for the website to function properly. If you are running a slower boat, the exact location of the ventilation plate is less important. The clamp bracket on the latest Mercury Four-Stoke-model outboards has five mounting bolt holes spaced .75 inches apart. stream
|. I believe 20 to 21 inches is the optimum length for a lengthy shaft. All rights reserved. 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. It is possible that the motor could hang low while transporting on the boat trailer causing future boat repairs. Anything bigger than that your obviously going to need an extra long shaft.
On the downside, a higher mount can interfere with the boaters steering capabilities. Keith Allen, a 1979 graduate of Valley City State College, has worked at a variety of jobs including computer operator, medical clinic manager, radio talk show host and potato sorter. The general guideline for longer shaft outboards is that the transom height should be at least 20 inches (50,8cm) above the waterline. Its important to note that manufacturers call their models different things. s.setAttribute("type", "text/javascript"); Analytical cookies are used to understand how visitors interact with the website. The prop will be in cleaner, harder water as it advances farther aft, making it more efficient. Eq*^?6R83e+j}UY.(M7k]~4g)g ~wmS{ O7t/o(W|X? For slower boats, its less critical to. Some may call it a standard length while others may call it a short or a long shaft. With such an important, long-term, and expensive upgrade, its never a bad idea to double-check. With some boats I have a pretty good idea as to what length motor should be hung on them. These are vertically aligned so the boater can make adjustments. A2: Instead of changing to the short outboard shaft, you can try the Jack Plate first. Boaters who consider going with a higher mount can see increased speeds. Safely but briskly accelerate. It was a 23-foot Crestliner Grand Cayman pontoon boat. function loadScript(script) { 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. What matters is the actual measurement in the specifications, not the name. As summer approaches there will be more boaters taking to the water. In the case of a larger offshore boat, it may be to the top of a cutout on the . Many single-engine boats mount a smaller auxiliary motor for emergency use. Pretty easy to figure out but like I said its crucial to pairing a motor with a boat. Remember, if you use a longer outboard shaft than you need you will be increasing your draft. Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. To do so, take a measurement from the very top to the very bottom of the transom in the precise center. You need JavaScript enabled to view it. Propshaft in
As you can see, the measurement is about 2 1/2". Then adjust the motor in a higher hole with a flat head screwdriver. Disclaimer: As an affiliate I may earn a commission on any qualifying purchases, including those from Amazon.com, at no extra cost to you read more. If you went too long it would still work but it may lack in performance. 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. The propellers will also have trouble reaching the water. Your goal is to measure how the outboard will sit, so start from the clamping plate and follow the centerline of the hull. When mounting the engine, you want the cavitation plate to be 1 above the boat bottom for every 12 away from the transom. This exhaust port should be about 1 inch above the water line when the boat is idling. However, the motor should not be raised more than 5 inches above the standard position. 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. resting on the transom if you had the motor all the way down on the boat
As a dealer I don't really like hearing this because there is a chance it could go either way and you have to get it right. We also use third-party cookies that help us analyze and understand how you use this website. Chances are the boat was designed with a specific size of outboard in mind. Check out the Westshore Marine & Leisure google plus page! Having the cavitation plate too low will cause excess drag and reduced performance at high speeds. %
The motor is what powers the boat so the two go hand-in-hand. (Any measurement given as "off the transom"
A long shaft engine requires a height of 20 and extra-long shaft engines will need a transom height of 25. function gtag(){dataLayer.push(arguments);} High powered boats usually only come in long and extra-long variants. If you have a question or need additional information. Owners of bass boats, RIBs, or offshore fishing boats need to get this right. Beyond motorboats designed for large outboards, you will see outboards hanging on the sterns of everything from small canoes to large cruising sailboats. Copyright 2017 Dealer Spike All Rights Reserved. One of the main concerns is causing the engine to overheat if not enough water reaches the engine to keep it cool. This restriction includes most fishing boats and longer sailboats. To do so, take a measurement from the very top to the very bottom of the transom in the precise center. In the case of a dinghy or johnboat, this point may be the top of the transom. It will ensure that the outboards trim will be effective, and it will save you gas too. clearInterval(interval); Any owner seeking the last bit of speed from an outboard-powered boat should grab a yard stick. It also decreases the boats lift and increases the time it takes for the boat to reach plane. However, there may be times when a boater strays away from these recommendations. Where Onboard a Boat is the Transom Located and More About Transom Heights A propeller operates based on the height of the transom.