F4SMHA Yamaha 4hp Short Shaft Portable Outboard Motor
Original price was: $1,615.51.$1,210.48Current price is: $1,210.48.
| Specifications | |
|---|---|
| Engine Type | OHV, 1-cylinder |
| Displacement | 139.0 cc |
| Bore x Stroke | 62 x 46 mm |
| Recommended Max RPM | 4000-5000 |
| Lubrication System | Wet sump |
| Fuel Management | Carb |
| Ignition | CDI |
| Starter System | Manual Choke |
| Alternator Output | 12V-6Amp with Rectifier Regulator (optional) |
| Operation Method | Tiller Handle |
| Trim & Tilt Method | Manual Tilt |
| Fuel Tank Capacity | 1.1 L |
| Gear Ratio | 2.08:1 |
| Previous model code(s) | F4BMHS |
The Yamaha F4SMHA is a 4hp 4-stroke short-shaft portable outboard motor engineered for effortless transport and dependable performance on small boats, tenders, and dinghies.
Unlike 2-stroke alternatives, the F4SMHA runs on a clean 4-stroke cycle, requires no fuel premixing, delivers significantly lower emissions, operates more quietly, and offers better long-term fuel economy. Yamaha’s renowned engineering ensures this outboard starts reliably and runs consistently, even in demanding conditions.
A standout feature is Yamaha’s side-carry transport system, which allows the engine to be stored and transported on its side without draining the oil first, ideal for car boots, boat lockers, and tight storage spaces. That means more time on the water and less hassle at the dock.
Key Features
4-Stroke — No Premixing
The wet sump lubrication system uses standard engine oil separately from the fuel, eliminating the need for fuel-oil premixing. This design provides lower emissions, improved fuel economy, and cleaner operation compared to equivalent 2-stroke engines.
Side-Carry Storage System
The F4SMHA can be stored and transported on either side without draining the engine oil. This unique Yamaha feature makes transportation easier and is ideal for vehicle storage and compact boat lockers.
CDI Electronic Ignition
Capacitor Discharge Ignition (CDI) technology delivers a strong and reliable spark in all operating conditions. Paired with a manual choke, it ensures dependable starting performance, even in cold weather.
3-Position Tilt Mechanism
The manual tilt system offers three locking positions, allowing you to adjust the engine angle to suit varying transom depths and boating conditions, from shallow-water operation to open-water cruising.
Dual Fuel-Line Connections
A built-in 1.1-litre fuel tank is perfect for short trips, while dual fuel-line connections allow quick attachment to a larger external fuel tank for extended range without requiring tools.
Optional 30W Alternator
An optional rectifier-regulated 12V alternator can be fitted to charge batteries and power onboard accessories. This feature is ideal for running fishing electronics, navigation equipment, or auxiliary lighting systems.
Technical Specifications
- Engine Type — Single-cylinder 4-stroke OHV
- Displacement — 123cc
- Bore × Stroke — 62 × 40mm
- Recommended Max RPM — 4,000 – 6,000 RPM
- Lubrication System — Wet sump
- Fuel Management — Carburettor
- Ignition — CDI (Capacitor Discharge Ignition)
- Starter System — Manual choke/recoil start
- Alternator Output — 30W (optional rectifier regulator)
- Operation Method — Tiller handle
- Trim & Tilt — Manual tilt, 3 locking positions
- Propeller Drive — 3-blade shallow-water drive
- Gear Ratio — 2.08:1
- Transom Height (Short Shaft) — 432mm / 15″
- Dry Weight — 27kg
- Built-in Fuel Tank — 1.1 litres
- Previous Model — F4MHS
F4SMHA vs F4LMHA: Short Shaft vs Long Shaft
The Yamaha F4SMHA and F4LMHA share the same 123cc 4-stroke engine, so performance and fuel efficiency are identical. The only difference is shaft length. The F4SMHA has a 432mm (15″) short shaft for small boats with standard transoms, while the F4LMHA has a 508mm (20″) long shaft for deeper transoms like larger dinghies, runabouts, and pontoons.
Choosing the wrong shaft can hurt performance; too short causes cavitation, too long adds drag. Measure from the transom top to the waterline: up to 15″ means F4SMHA; 17–20″ means F4LMHA. If unsure, go for the longer shaft for smoother operation.
Frequently Asked Questions
Does the Yamaha F4SMHA require premixed fuel?
No. The F4SMHA is a 4-stroke engine with a wet sump lubrication system. Engine oil is filled separately, just like a car. Run it on standard unleaded petrol; no fuel-oil premixing needed at any point.
What is the difference between the F4SMHA and F4LMHA?
The engines are mechanically identical. The F4SMHA has a short shaft (432mm / 15″) suited to standard transoms. The F4LMHA has a long shaft (508mm / 20″) for deeper transoms. Always measure your transom height before purchasing.
Can I store the F4SMHA on its side?
Yes, this is a purpose-built design feature. The side-carry bracket allows you to store, carry, and transport the motor horizontally on either side without draining the engine oil first. Ideal for car boots, van floors, and tight boat lockers.
Does it come with a remote fuel tank?
The F4SMHA includes a built-in 1.1-litre fuel tank. It also features dual fuel-line connections to attach a larger portable remote tank for extended range. The remote tank is not included but is available separately.
Is the alternator included as standard?
No. The 30W alternator with rectifier regulator for 12V battery charging is an optional accessory and is not included as standard. Contact our team to add it at the time of purchase.
How heavy is the F4SMHA?
The F4SMHA weighs 27kg dry. Combined with the side-carry handle, it is manageable for one person for short carries to and from the water.
What warranty does the F4SMHA come with?
The Yamaha F4SMHA comes with the official Yamaha manufacturer’s warranty. Coverage terms vary by region. Contact our team before purchasing for warranty details applicable to your location.
