Measure from the bottom of your outboard's engine compartment down to the bottom of the cavitation plate -- the horizontal metal wing above the propeller. If the measurement lies between 19 and 21 inches, it's a short shaft. If it's about five inches longer than that, it's a long shaft.
How do you measure outboard motor shaft length?
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.
How do you measure a boat for a new hull?
Measure straight down to the lowest point on the hull. For vee-shaped hulls, the lowest spot of the hull will come to point, while on flat-bottomed boats it will be more or less level. The lowest point will likely be directly under your drain plug if you’ve got one.
What is the best outboard shaft length for my Boat?
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.
How do you measure the length of a boat transom?
So you should just measure the height of the boat’s transom from the center down to the lowest point of the hull, and compare transom height with the outboard shaft length numbers. Attention: Remember to measure the outboard shaft length straight up and down instead of measuring along the transom.
How is outboard shaft length measured?
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. Later in the article is an image that shows you exactly where to measure.
How do I know if I have a long or short shaft?
Short or Long -- or Extra Long? Measure from the bottom of your outboard's engine compartment down to the bottom of the cavitation plate -- the horizontal metal wing above the propeller. If the measurement lies between 19 and 21 inches, it's a short shaft. If it's about five inches longer than that, it's a long shaft.
How do you determine shaft length?
The following lists what length of shafts you should consider for certain heights. If the crease where your wrist and hand meet to the floor is: 29 to 32 inches = irons should be based on a 5-iron of 37 inches. 33 to 34 inches = irons should be based on a 5-iron of 37 1/2 inches.
How do you measure a lower unit shaft?
0:241:21Helpful Hints - How to Measure for Outboard Shaft Length - YouTubeYouTubeStart of suggested clipEnd of suggested clipWhen measuring your transom height take your tape measure measure from the highest point of theMoreWhen measuring your transom height take your tape measure measure from the highest point of the transom. To the lowest part of the v.
How do I know if my outboard is short or long shaft?
For electric outboards, the shaft length is measured from the top of the clamp bracket to the center of the propeller. For gas outboards, it's measured from the top of the clamp bracket to the anti-ventilation plate.
How do you measure a short shaft or long shaft on a boat motor?
Measure from the top of your transom to the bottom of your keel. If it is from 15" to 17" long you'll need to get a Tohatsu outboard with a "short" shaft. If it is from 20" to 22" long you'll need our "long" shaft outboard.
What shaft length should I use?
Driver Shaft Length Based Solely on HeightHeight (feet/inches)Driver Shaft Length5'4″-5'7″45.5″5'2″-5'4″45″5'0″-5'2″44.5″4'10”-5'0″44″6 more rows•May 9, 2021
How do you measure the transom height of an outboard motor?
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. On most newer center consoles and offshore boat transoms might include a rear door leading to a swim platform as well as a molded setback bracket.
How is drive shaft length measured?
How to Measure a Driveshaft with a Slip Yoke and U-jointPlace one end of the tape measure near the middle of the front u-joint.Place the other end of the tape measure near the middle of the rear u-joint.Note the measurement on the tape measure to determine the length of the driveshaft (without the slip yoke).
How do you measure outboard lower unit shaft?
0:293:39What Shaft Length Do I Need? - YouTubeYouTubeStart of suggested clipEnd of suggested clipFrom the transom to the keel. The way that we do that is we take out just a standard tape measure orMoreFrom the transom to the keel. The way that we do that is we take out just a standard tape measure or a yardstick you measure from the transom all the way down to the keel transom to the keel.
What size outboard shaft do I need?
To do so, you will want to measure at the exact center of the transom from the very top to the very bottom. If it measures 15" or with in a inch of that you will need a short shaft outboard. If it measures anywhere from 17" to around 22", then your going to want to go with a long shaft motor.
How far below the bottom of the boat should the prop be?
If you have a short shaft motor, the top most part of the transom and the lower most part of the boat should be about 15 to 16 inches.
Why is the outboard shaft lower than the standard point?
Smaller boats. Mounting the outboard a little bit lower than the standard point could avoid the possible ventilation and slip on acceleration. Although the longer outboard shaft length can lead to lower speed and more drag, the boat can push a heavier load.
What happens if your outboard shaft is too long?
Outboard shaft length plays a crucial role in the performance of your boat. With the outboard shaft length too long, meaning the prop is too deep in the water, the engine won’t be as efficient, and the fuel burn is high. Also, the boat will be more likely to hit bottom or submerge objects such as rocks or logs.
How far away from the transom should the cavitation plate be?
When mounting the engine, you want the cavitation plate to be 1″ above the boat bottom for every 12″ away from the transom. To sum up, there is a simple calculator ...
How far below the bottom is the cavitation plate on an inflatable boat?
So if you are measuring the outboard shaft length for smaller boats, inflatables, dinghies, sailboat or other low-speed work boats, the cavitation plate is often about 2″ below the bottom. Transom distance.
Why does my outboard boat slip on acceleration?
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.
Is a 20 shaft a long shaft?
Say the 20’’ shaft is a long shaft length for gas engines, but it is a short shaft length for electric outboard motors. And that’s usually the case since the electric outboards are designed with larger and more efficient propeller that needs longer shaft. So it’s easier and safer to communicate with the dealer with the exact measurement ...
How many inches is a short shaft?
To be clear, if I take a lower unit off and measure the driveshaft at 17", that would be considered a short shaft, being closest to 15 inches.
How long is a 15" motor shaft?
When an engine is referred to as a short shaft, it's considered to be a 15" motor. Long shaft is considered 20”. An XL shaft is 25". In rare cases, mostly in big saltwater models, engines were made in a 30" shaft, or an XXL. In none of these cases is the shaft length exactly 15, 20, or 25 inches.
How to measure for a lower unit replacement?
If you are measuring for a lower unit replacement and your original lower unit is off of the engine, simply measure from the top of the waterpump to the top of your driveshaft. A shaft length that falls closest to 15 inches is short, closest to 20 inches is long, and so on.
How to tell if an outboard is a long shaft or short shaft?
If the measurement lies between 19 and 21 inches, it's a short shaft. If it's about five inches longer than that, it's a long shaft. If it's about 10 inches longer than the short shaft's 20 inches, it's an extra-long shaft.
What is an outboard shaft?
An outboard might come equipped with a short shaft, a long shaft or an extra-long shaft, the shaft being the driveshaft that connects the powerhead -- the engine -- to the lower unit, where the propeller shaft, the propeller and the forward and reverse gears all live.
Is a long shaft a long shaft?
If it's about five inches longer than that, it's a long shaft. If it's about 10 inches longer than the short shaft's 20 inches, it's an extra-long shaft. Will Charpentier is a writer who specializes in boating and maritime subjects.
