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.
Can I use a long shaft motor on a short shaft boat?
Re: Longshaft motor on a short transom skiff? It will will *run* fine, but it can cause bad handling. Also trim position settings will have a greater effect.
Does shaft length matter on outboard motor?
Conclusion. Picking the right shaft length for your outboard is an essential step in getting the best performance from your boat. If you have a fast boat, getting the outboard's cavitation plate at the same level of the hull will ensure quick hole shot and fast top-end speeds.
How do I know if my engine is long or short shaft?
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.
Can you run a short shaft outboard on a 20 inch transom?
Can You Run A Short Shaft Outboard On A 20 Inch Transom? A shorter shaft can work on a 20″ transom by setting the motor back properly, without disturbing it too much.
40 related questions foundHow far below 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 length of outboard shaft do I need?
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 size outboard do I need for a 15 foot boat?
What Size Outboard Do I Need For A 15 Foot Boat? You should find one to match your budget for a boat that is about 10-15 feet long. These lightweight boats won't be quite as powerful as larger cars so they'll have an engine about 15 horsepower in the range of 20-30 horsepower.
Can you use a short shaft outboard on a long transom?
If you set the motor back far enough without jacking it up, a short shaft will work on a 20" transom.
What height should an outboard motor be set at?
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″.
What is transom height on a 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.
Can I use a long shaft on a jon boat?
A long shaft will definately work. Wawasee has a jon boat and motor that his grandfather give him that was a low transom boat and (Monarch mod vee??) and an old 20 hp Mercury. I rode in the boat a few times and it actually worked okay.
What happens if outboard is too low?
If the outboard is too low, it creates excessive drag, which cuts into speed and fuel efficiency. 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.
How do you increase transom height?
One non-invasive way of raising the transom on an aluminum boat is to create a "lift" — a bracket that fits over the transom — to increase the motor's height. The completed bracket forms a channel, and the top of the channel holds the top of the outboard bracket a few inches above the transom of the boat.
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.
Can I convert a long shaft outboard to a short shaft?
The only thing to do is get a jack plate or raise your transom. Nothing's impossible. Keep an eye on ebay for the parts you may need. many outboards of that size actually have a one piece drive shaft and a 5" extension on the exhaust housing (part between the cowlings and the lower unit on the outside.)
Can you switch a short shaft 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 motor can you put on a 14 foot jon boat?
Typical horsepower for a 14-foot jon boat would be between 15 HP and 20 HP although up to 25 HP is not uncommon either. 20 HP can comfortably give you a top speed of 20mph, potentially even stretching to 25mph depending on weather conditions and the weight on the boat.
How big of a motor can I put on a 16 foot boat?
To achieve maximum efficiency, you'll have to give it 50 to 300 horsepower. There's a range of the required power as you take into consideration the size and usage. An aluminum boat that is 16 feet long needs to have a 60 horsepower motor. Once equipped, it can have a speed of 25 to 30 miles per hour.
What size motor do I need for a 20 foot boat?
Center console boats from 20'-25' can usually perform well with a single outboard from 200 to 300-hp, depending on load and top speed expectations. Over 25'-26', twin engines are typically recommended.
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 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 I know what pitch prop I need?
When choosing a propeller, choose a pitch that will keep the engine RPM in its recommended operating range. Going under the range will cause the boat to lug, while going over can cause engine strain. Blades have other important features built into their design. Rake is the angle between the blade and the hub.
