Description
Mercury 4 HP FourStroke (1F04201KK) — Portable Power for Small Boats
The Mercury 1F04201KK is a reliable 4 HP FourStroke tiller outboard designed for quiet, fuel-efficient performance on small craft. It features a 15" short shaft, manual tilt/trim for shallow-water maneuvering, and manual start for simple, battery-free operation.
Why Owners Choose This 4 HP
- Portable & Practical: Compact size for easy carrying, stowing, and quick installs on dinghies and tenders.
- Quiet FourStroke Efficiency: Smooth running with low emissions and excellent fuel economy.
- Tiller Control: Direct, confident handling for docks, ramps, and tight quarters.
- Manual Tilt/Trim: Fine-tune running angle and protect the prop in shallow areas.
- Manual Start: Dependable pull-start—no battery required for remote launches.
Engine Specifications
| Manufacturer | Mercury Marine |
|---|---|
| Model | 1F04201KK (4MH) |
| Horsepower / kW | 4 HP / 2.9 kW |
| Engine Type | Four-stroke, single-cylinder (tiller) |
| Displacement | ~123 cc (typical for this class) |
| Valve Train | OHV (pushrod) |
| Fuel Induction | Carbureted |
| Ignition | Digital CDI |
| Full-Throttle RPM | 5,000–6,000 RPM (target upper half with typical load) |
| Gear Shift | F-N-R (forward-neutral-reverse) |
| Gear Ratio | 2.15:1 |
| Shaft Length | 15" (short shaft) |
| Tilt / Trim | Manual multi-position |
| Steering | Tiller handle |
| Exhaust | Through-prop exhaust |
| Cooling | Water-cooled with thermostat |
| Charging | Optional/limited on this class (verify if equipped) |
| Dry Weight | ~55–60 lb (varies by configuration) |
| Fuel Type | Unleaded 87 octane (up to E10 acceptable) |
| Fuel Tank | Integral on-engine tank; external tank compatible on many setups |
| Recommended Oil | Mercury FourStroke 10W-30 |
| Emissions | Meets EPA / typically CARB 3-Star |
| Use Case Fit | Dinghies, tenders, inflatables, canoes, small jon boats |
| Best Practices | Select prop to hold WOT in range; measure transom for 15" fit; keep fuel fresh |
| Verification | Confirm exact specs (weight, charging, tank) on the unit’s label/serial |
Great For
- Yacht tenders & dinghies
- Inflatable boats & canoes
- Small jon boats & pond skiffs
- Quiet trolling and short, efficient runs
Rigging & Operation Notes
- Mounting: Designed for 15" short-shaft transoms—measure from keel to transom top to confirm.
- Prop Selection: Target the 5,000–6,000 RPM band at WOT with your usual load and water conditions.
- Fuel Care: Use fresh 87-octane; up to 10% ethanol is acceptable. Treat and rotate fuel for storage.
- Maintenance: Follow Mercury intervals for oil, gear lube, and water-pump/impeller service.
Get Pricing & Availability
Contact our certified team for current pricing, lead times, and recommended accessories for your boat.
Frequently Asked Questions
What boats match a 4 HP Mercury FourStroke?
Great for dinghies, inflatables, canoes, small jon boats, and tenders where light weight, easy starting, and quiet operation matter most.
Does this model have reverse?
Most 4 HP configurations include forward-neutral-reverse (F-N-R) shifting for easier dockside handling. Verify your specific unit before purchase.
What fuel and oil should I use?
Use regular unleaded 87-octane gasoline (E10 acceptable). Follow Mercury guidance for FourStroke 10W-30 engine oil and standard maintenance intervals.
Will it charge a battery?
Charging output on small portables is limited or optional. If you need 12V charging, ask about equipped units or consider a portable charger.
What shaft length do I need?
This model is a 15" short-shaft—ideal for transoms measuring ~15" from the keel to the top of the transom. Measure your boat to confirm.
How should I pick the right prop?
Choose pitch to keep wide-open throttle within the typical 4-hp operating band with your usual load. We can recommend a prop once we know your boat and conditions.
Any storage or fuel tips?
Use fresh fuel, add stabilizer for off-season storage, and run the motor on clean fuel before layup. Follow Mercury’s steps for winterizing and spring recommissioning.
Is manual start difficult?
These engines are designed for easy pull-start. Keep fuel fresh, follow proper starting procedure, and service on schedule for dependable starts.