How Do You Measure The Shaft Length On A Pontoon Boat?

The trolling motor shaft length is measured from the bottom of the head, down to the top of the propeller housing. If you measure this incorrectly, you’ll get the wrong size, so be careful.

How do you measure shaft on pontoon boat?

Ideally, to measure the correct shaft length needed for your boat. You should measure the distance from where the motor will be mounted down to the water. Then you should add about 18-22 inches extra.

How do I know if my boat motor is long or short 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.

How do you measure a transom on a pontoon boat?

The transom is the flat vertical section at the rear of the boat. It is where the outboard is mounted, and some boat owners place the name of the boat. 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.

How do you measure the shaft length on an outboard motor?

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 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.

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.

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 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.

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 convert 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.

Where is the transom on a pontoon boat?

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Transom: The back section of the hull upon which the outboard is mounted. Trim: The angle by which the outboard is adjusted to improve performance. Twin Engine: A boat with two outboards.

How far in the water should an outboard motor be on a pontoon?

A boat rigger’s rule of thumb is that the motor can be raised one inch for each eight to 10 inches of distance between the transom and prop. As the prop moves further aft, it’s also likely to be in cleaner, “harder” water, and be more efficient.

What is the difference between short shaft and long shaft outboards?

If your boat has a Transom Height 15″-16″ you will need short shaft and if it is 20″-21″ you will require long shaft engine.Auxiliary engines for yachts usually require a long shaft engine so as to make sure the propeller remains well submerged when the boat is in a seaway.

How do you tell if my outboard is 2 or 4 stroke?

Here are some easy ways to tell if your engine is two-cycle or four-cycle:

1. Look at the fuel cap.
2. Look for stickers labeling the equipment (e.g., “Four Cycle” or “No Fuel Mixing”).
3. Look for an engine oil fill cap.
4. The Operator’s Manual will have engine fuel and oil information in it.

How do you know if your outboard is too low?

An outboard that is mounted too low will limit your boat’s optimal operation. You can often tell that an outboard is too low if you are experiencing sluggish speeds, poor handling, excessive spray, porpoising, or even water pushing up into the cowling.

How far should the cavitation plate be below the boat?

The cavitation plate should be nearly even with or slightly below the bottom. For a short shaft the vertical measurement of the transom should be about 15 inches.

How do you know if your outboard is too high?

Too high usually results in low water pressure, prop letting go in turns, or lack of bow lift are usually the telltale signs. Sometimes porpoising is caused by too much bow lift and dropping the motor will give it more bite and make it worse.

How do you measure a shaft?

Inputs that we need to calculate shaft diameter

1. τ = Torsional stress induced at the outer surface of the shaft (Maximum Shear stress).
2. r = Radius of the shaft.
3. T = Twisting Moment or Torque.
4. J = Polar moment of inertia.
5. C = Modulus of rigidity for the shaft material.
6. l = Length of the shaft.

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 use a short shaft outboard on a pontoon boat?

You should have the long shaft version of the motor. Small outboard motors normally come in either short shaft for fishing boats, and long shaft for use on pontoons and sailboats as an auxiliary to the sail. Having the long shaft would be preferable.