Tohatsu model number meaning comes down to a few building blocks: the MFS prefix marks a four-stroke outboard, the number is the horsepower, the letter after it identifies the model generation, and the letters at the end describe the shaft length and features such as start type and controls. An MFS3.5CS, for example, is a 3.5 hp four-stroke, C generation, with a short shaft. Read the code left to right and most of the mystery disappears.
The catch is that Tohatsu packs several features into a short string of letters, and not every letter is used the same way across every horsepower size and model year. Below I explain the parts of the code that are consistent and well documented, then show you how to confirm the rest so you order the right motor the first time.
Tohatsu model number meaning, piece by piece
Take a code like MFS9.9EEFTUL and split it into pieces:
- MFS: the four-stroke family. Tohatsu’s outboard codes start with M, and FS indicates four-stroke. You will also see older two-stroke Tohatsu codes with different prefixes on the used market, so do not assume every Tohatsu is an MFS.
- 9.9: rated horsepower.
- E (first letter after the horsepower): the series or generation letter. On a 9.9 or 20 hp this is often E; on a 3.5 hp it is C; on the 4, 5 and 6 hp motors you will see C or D depending on the generation. Parts often differ between generations, so this letter matters when you order spares.
- The middle letters: features such as start type, steering setup and tilt or trim.
- The last letters: shaft length.
Shaft length letters: S, L and UL
This is the part of the code you most need to get right, and luckily it is the most consistent. On Tohatsu four-strokes the final letters indicate shaft length:
| Ending | Shaft length | Common use |
|---|---|---|
| S | Short shaft, about 15 inches | Small tenders, jon boats, inflatables, low transoms |
| L | Long shaft, about 20 inches | Most small aluminum and fiberglass boats with a 20-inch transom |
| UL | Ultra long shaft, about 25 inches | Sailboats, some pontoons and higher transoms |
So the Tohatsu MFS3.5CS is a short-shaft 3.5 hp, while the Tohatsu MFS9.9EL is a long-shaft 9.9 hp. Measure your transom from the top of the mounting surface to the bottom of the hull before you buy. Our guide on outboard shaft length shows how, and why too short or too long both cause problems.
Start type, steering and tilt letters
The letters between the generation letter and the shaft length describe how the motor starts, how you steer it and whether it has power tilt. Here is what you can generally read from them:
- No extra letters, as in MFS9.9EL or MFS3.5CS: a basic configuration. On these small motors that means manual pull start and tiller steering.
- A second E, as in MFS9.9EEFTUL or MFS20EEPTL: Tohatsu commonly uses this to indicate electric start.
- T: commonly indicates power tilt or power trim and tilt.
- F, P and W: these relate to the steering and control setup, such as remote control versus tiller. Their exact meaning can vary by model and year, so I do not recommend decoding them from memory.
Take the Tohatsu MFS9.9EEFTUL as an example. You can read 9.9 hp, E generation, electric start, a power tilt feature and a 25-inch shaft from the code with confidence. For whether it is set up for remote steering or tiller, read the product description and the Tohatsu literature for that model. The same goes for the Tohatsu MFS20EEFTL, a 20 hp long-shaft motor in the same family.
The honest rule: if a letter in the code is not one of the well-established ones above, confirm it in the Tohatsu owner’s manual or on the model decal rather than guessing. Remote and tiller versions of the same horsepower need different rigging, and an electric start motor needs a battery and charging setup.
Special versions: Sail Pro and high thrust
Some Tohatsu names add words to the code. The Sail Pro models, such as the MFS6 and MFS5 Sail Pro, are aimed at sailboats and similar displacement hulls that need thrust at low speed more than top speed. They are usually paired with long or ultra long shafts. If you run a sailboat or heavy displacement boat, look at these versions first and read the listing details carefully.
Where to find the model number on your motor
When you are replacing a Tohatsu or ordering parts, start with what is already on the boat:
- Find the identification decal. On most outboards it is on the transom clamp bracket or swivel bracket. It shows the model code and serial number.
- Check the owner’s manual. The specification pages list every version of that motor with its code.
- Write down the full code exactly, including every letter. MFS9.9EEFTUL and MFS9.9EEPTUL are close, but not the same motor.
- Note the serial number as well, because parts can change within a model’s production run.
For a broader walkthrough of decals, plates and serial numbers across brands, see how to identify an outboard before ordering a replacement.
Why the code matters when you buy
A wrong letter can mean a motor that sits too high on the transom and cavitates, one that sits too low and drags, or one that arrives as a tiller when your boat is rigged for remote controls. Decoding the model number up front saves you the hassle. When in doubt, go to the source: Tohatsu publishes owner’s manuals and specifications for its outboards, and an authorized Tohatsu dealer can confirm a code against the serial number.
Shopping Tohatsu outboards
Once you have decoded what your boat needs, browse the full Tohatsu outboard lineup or compare against other brands in our outboard motors category. Match the code on the listing to your notes, and check the product page specs before you order.
Frequently asked questions
What does MFS stand for on a Tohatsu outboard?
MFS identifies Tohatsu’s four-stroke outboards. The M is the outboard prefix and FS stands for four-stroke.
What is the difference between MFS9.9ES and MFS9.9EL?
The ending letter is the shaft length. S is a short shaft, about 15 inches, and L is a long shaft, about 20 inches. The rest of the model is the same horsepower and generation.
What does UL mean in a Tohatsu model number?
UL means ultra long shaft, about 25 inches. It is common on sailboat motors and boats with tall transoms.
Can I tell if a Tohatsu is tiller or remote from the model number?
Sometimes, but the steering letters are not used identically across every model and year. Basic codes like MFS3.5CS and MFS9.9EL are tiller motors. For anything with extra letters, confirm in the owner’s manual, on the decal or in the product description.
Start with the right reference 
Plan the arrival Always confirm the exact model, part number, condition and included components on the product listing. For a compatibility question, contact TorqueHarbor before ordering.