How to measure boat motor shaft length

How does one measure shaft length. I have a Honda 115 on it and want to upgrade to a 150 HP motor but not sure of the length of shaft I need.

A shaft length that falls closest to 15 inches is short closest to 20 inches is long and so on.

How to measure boat motor shaft length. To sum up there is a simple calculator of the shaft length for outboard motors. Outboard Shaft Length Transom Height - Factors. The Factors indicates the adjustment affected by on your boat type the outboard working environment and the transom distance as discussed above.

One of the most common questions we receive is How do I measure my boat to find the appropriate shaft length for my outboard. This video will cover the pr. Here is the full answer.

For this matter the propeller shaft length is measured from the inner top side of the motors mounting bracket to the horizontal anti-ventilation plate thats above the propeller. Note that sometimes the anti-ventilation plate is called anti cavitation plate although this is an incorrect term. Outboard Motor Shaft Length.

How do I measure. If mounting directly to a boat transom. Measure from the top of the transom down to the bottom of the hull or keel lowest point.

Measure the area of the transom directly where the engine will be mounted. This measurement is primarily designed for single motor propulsion. Motor Shaft Length Step 1 Place the tip of a yardstick on the top of the mounting clamp bracket that secures it to the boat.

Step 2 Read the measurement at the bottom of the cavitation plate. The cavitation plate is the flat area that is horizontal above the propeller. Write the shaft length down in inches on paper with a pen.

Well in order to get the right shaft length first measure the transom height the length from the top of the boat transom to the bottom of the boat. After that you could choose the recommended shaft length based according to the transom height. Use figures and measure your shaft please no confusion is possible with figures.

Standard shaft lengths are 15 20 and 25 38 50 and 63 cm. Those shaft lengths are an industry standard but there are exceptions. For mid-range engines the most common shaft length is 20 508 mm.

15 shafts should be reserved to protected waters. 25 shaft are rare below 100 HP. Mar 14 2014.

How does one measure shaft length. You should find values near 15 20 and 25 short long extra long. Although on my outboard I was never able to get an exact match when I measured it IIRC.

I think I came up with something around 17 so it wasis a short shaft. Just measure your boat from the top of the transom to the bottom of your boat to get the transom height. A 20 is considered to be a standard or long length.

To achieve this the motor itself has to be attached at the correct height. Beginning boaters should be aware of the boats measurements. 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. A shaft length that falls closest to 15 inches is short closest to 20 inches is long and so on. If your engine is mounted on a boat or a stand locate the transom bracket of your engine and use the guide below to measure.

How to Measure Shaft Length Guide 15 Short 20 Long 25 XL 30 XXL How Tos Maintenance Know Your Boat. Okay I admit it I do not know how to measure my outboard motor shaft length on my 2003 188 Fundeck. I have a Honda 115 on it and want to upgrade to a 150 HP motor but not sure of the length of shaft I need.

Yeah you want a 20. The 25 part is on the centerline of the boat over on the side where a kicker is mounted a 20 works perfect and like Tmac said it will drag in the water. The only time I ever put a 25 kicker on was a Boston Whaler.

As such its important to make sure you select the proper shaft length. Start by measuring the distance from the horizontal mounting point on the bow to the waterline then add 20 to this measurement. Generally you will want a shaft length that is equal to or greater than this sum but not less.

If it measures anywhere from 17 to around 22 then your going to want to go with a long shaft motor. Anything bigger than that your obviously going to need an extra long shaft. When the right length motor is hung on the transom of a boat the cavitation plate the large plate that extends out over the propeller should be even with the very.

With bow-mounted motors there is much greater variation in shaft length requirements. 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. 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. Boat Type One of the factors is that it depends on the transom the vertical part at the read of the boat and boat hulls.

Determine the motor shafts length. Use a tape measure and determine the motor shafts length by measuring from the base of the head down to the propeller housing in inches. Steps to measure transom or bow height Measuring the height of your boat from the water is equally if not more important than measuring your motor.

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. Driveshaft lengths are standard throughout the boating industry. Minnkota specsThe shaft length is from the base of the control box or head down to the collar on the motor or lower unit.

To find the shaft length requirements for your boat. Measure from deck where the motor is to be mounted down to the water line of the boat when at rest. Add 16 to 20 inches to this measurement.

30 1-800-630-1233 Call For Customer Service. Outboard Motors for Sale. Motor Shaft Length with 20 Transom Need Advise Please.

By JL8Jeff 06 Aug 2017 2338. I measured my transom at 225 right next to the tunnel. The tunnel is 25 - 3 and the motor is sitting 25 above the top of the transom.

So you would need the 15 short shaft with the 20 transom or you would need a riser plate to lift it 5-6.