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.

How far should a cavitation plate be from the bottom of the boat?

The dealer set it at 1/2" above the bottom of the hull when the motor is sitting level or straight up and down. When the motor is trimmed all the way down it is 1/2" below the bottom of the boat but when trimmed up just a little there is slippage or some cavitation.

How far should the prop be below the hull?

Normally the rule of thumb on prop to hull clearances is a minimum of 10% of the prop diameter; yours would be 1.4" with your prop. This is especially true on relatively high speed highly loaded props such as these boats see with 200+ hp with 1 to 1 gearboxes.

How deep should your propeller be in the water?

Determining the proper trolling motor shaft length is one of the key aspects of finding the right motor for your boat. It will help ensure that the motors' shaft is long enough to keep the propeller submerged at least 12" below the water line in your specific fishing conditions.

How do you know if your outboard is mounted too low?

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. That's a very brief, basic accounting of symptoms, but you'll usually find at least one of these symptoms if your motor is too low.

Got BOAT Prop PROBLEMS? Cavitation Vs. Ventilation!!!

How deep should my outboard sit in the water?

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 is the correct height to mount an outboard motor?

Industry standards dictate that for short shaft engines the transom height should be 15″. A long shaft engine requires a height of 20″ and extra-long shaft engines will need a transom height of 25″.

How do you know if your outboard is too high?

If it's too high, the propeller tends to ventilate, losing its bite on the water and blowing out while turning and in steep seas. “If the prop consistently ventilates when heading down a steep wave, the outboard is probably set too high,” says Dean Corbisier, advertising and public relations manager for Suzuki Marine.

Should cavitation plate be underwater?

your cavitation plate should be right at the water level. As a rule of thumb it should be 1 inch above the hull for every 12 inches back. (if you have a eurotransom, or bracket or something.) If your cavitation plate is under water you might get better performance if you raise the motor.

Where should the cavitation plate be?

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.

Why does the front of my boat go up?

Porpoising, or the bow bobbing up and dow, is caused by over-trimming at cruising speed; there's no longer enough hull in the water to support the weight of the boat. Either trim down a little until the porpoising stops, or increase boat speed slightly to create more lifting force under the hull.

Do cavitation plates really work?

They help prevent against "blow out" when taking off shallow. Plates with wings can help boats track better when running. Different boats will see varying improvements depending on the type of boat. Tunnel hull boats usually see the most dramatic performance increase from cavitation plates.

Will raising my outboard stop Porpoising?

By changing the engine setback, propeller selection and motor height, you adjust the dynamic balance of the hull. All of these can have a great effect on the porpoising movement. By raising the prop shaft higher, you shift the Dynamic Configuration forward and further reduce the trim angle.

Where should the cavitation plate be on a tunnel hull?

in the top 2 inches of highly aerated water coming out the tunnel. That means you have to be about 2 inches below the top to maintain bite. or just slightly above the top of the tunnel, depending on running angle.

Why does my outboard cavitation?

Why do boat propellers cavitate? The faster a boat propeller goes, the more bubbles are produced, which is the cause of cavitation. Slowing down or reducing surface pressure will reduce cavitation and therefore save your propeller from unnecessary abuse.

What is transom height?

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.

What causes a rooster tail on a boat?

Rooster tail is caused by a combination of Prop slip and motor height. If you motors are surfacing you will always have some small rooster tail.

Will raising outboard increase speed?

Raising an outboard higher on the transom can reduce drag and raise top speed.

How do you find the transom angle?

Measuring The Transom Angle (Degrees):

Slide forward until the short side of the rule (16") touches the transom straight up. Measuure the distance from the keel point to the inside corner of carpenter's square ruler (see sketch). Each 1/4" is equal to 1° degree.

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.