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 I know if my outboard is short or long shaft?
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 happens if your outboard shaft is too long?
If you went too long it would still work but it may lack in performance. You will also risk hitting bottom or submerge objects more frequently such as rocks or logs. If you go too short your more than likely going to cavitate and loose power.
How do you measure a motor shaft?
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 an electric motor shaft?
Measure down from the mounting surface of the transom or bow to the water level. Add 5″ to waterline measurement for fishing in rough water. Add 12″ to waterline measurement for steering a hand control motor while standing. Use this measurement and the tables below to find the appropriate trolling motor shaft length.
How do you measure the diameter of an electric motor shaft?
The frame number relates to the “D” dimension (distance from center of shaft to center bottom of mount). For a two digit frame divide the frame number by 16 to arrive at this dimension. For example, in the two-digit 56 frame, the “D” dimension is 3½” (56 divided by 16 = 3½”).
Can you run a short shaft outboard on a 20 inch transom?
If you set the motor back far enough without jacking it up, a short shaft will work on a 20″ transom.
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. For a long shaft, I think 20 to 21 inches is correct.
What happens if you put a long shaft motor on a short shaft boat?
You will drag your motor on the ground. You will have terrible performance, may not even get on plane depending on size of boat. Probably will lug due to hanging so low and could burn a hole through a piston. You really have to raise that engine up.
Can you change a short shaft outboard to a long shaft?
Your short shaft motor can also be sold as a long shaft with a Bay Kit. A long shaft motor can be sold as an extra long with a Bay Kit. Motors can be easily converted back to fit any customers need. Bay Kits come complete with all parts needed to make the conversion.
What size outboard do I need for a 15 foot boat?
Tips for selecting the right size hp for portable outboard motor for your boat.
| Motor HP | Boat length (feet) | Boat length (metres) |
|---|---|---|
| 5hp – 15hp | 8′ – 14′ | up to 4.2m |
| 9hp – 20hp | 11′ – 16′ | up to 4.5m |
| 20hp – 40hp | 13′ – 18′ | up to 5.0m |
| 40hp – 75hp | 14′ – 20′ | up to 5.5m |
How do you measure transom height?
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.
What tool do you use to measure a shaft?
Shaft measurement can be performed with a variety of metrology tools, from handheld devices such as micrometers and snap gages to high-end coordinate measuring machines (CMMs).
Can you change the shaft length on an outboard motor?
If you change to a short drive shaft, you’ll need to change the other shaft that runs through the exhaust tunnel, as it will be too long as well — you’ll need to install a new, shorter shift rod.
What is a shaft size?
The shaft diameter in Emetor is the diameter of the hole in the iron laminations that contains the shaft. For most motors, the diameter of the mechanical shaft and the diamter of the hole in the iron laminations that contains the shaft is the same.
How do you measure the shaft length on a Minn Kota trolling motor?
The shaft length on a trolling motor is measured from the base of the motor head down the the top of the motor compartment.
Can a trolling motor shaft be too long?
A trolling motor shaft can be too long. If the trolling motor shaft is too long, you risk the propeller hitting bottom or the inability to stow the motor properly. Too long of a shaft can not only damage the propeller but also the rest of the motor and the environment beneath the water as well.
What size shaft is on a 56 frame motor?
3-1/2 inches
Similarly, a 56 frame motor would have a shaft height of 3-1/2 inches.
What is a NEMA frame 56 motor shaft diameter?
Electrical motors NEMA frame dimensions.
| NEMA Frame Designation | Frame Dimensions (inches) | |
|---|---|---|
| D | U | |
| 56 | 3 1/2 | 5/8 |
| 56C | 3 1/2 | 5/8 |
| 56H | 3 1/2 | 5/8 |
What is shaft height motor?
The first two digits in the frame size designation give you information about shaft height (the distance from the shaft center to the mounting surface) in inches. For example, the shaft height is the first two digits divided by 4, so if you have a 324T frame motor then the shaft height is 32/4 = 8 inches.
Can you put a 20 inch motor on a 25 inch transom?
It is possible to mount a 20-inch shaft outboard motor on a transom designed for a 25-inch shaft motor, however the lower unit will be mounted too high and performance will suffer. It is possible to modify a motor to a longer shaft length, but this requires buying a spacer kit and perhaps a new drive shaft.
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