Product details
Your First Nitro Engine: A Real SOHC Twin You Build Yourself
Never built a running engine before? The ST-FL2 is made for that first step. It has a simple setup, push-button start, and a full build video to follow, all in the layout of a real car engine.
- 1Simple to tune. One carburetor and an adjustable cam, so there's just one mixture to learn instead of one per cylinder.
- 2Push-button start. A 480 brushed electric starter does the work. No pull cord and no starter box technique to master.
- 3Build along with video. Follow the full assembly video and the printed manual step by step.
- 4Real automotive design. SOHC inline twin in CNC-machined, anodized aluminum. A first engine you'll still want on display.
Hear it start up
You'll need the Starter Kit to fire up your ST-FL2. Order both together and the first 10 customers save the most.
- Add this engine and the Starter Kit to your cart.
- At checkout, enter code E50 for $50 off the engine and code M2026 for 10% off the Starter Kit.
- If yours is one of the first 10 orders, we'll refund $20 plus half of your Starter Kit price to your original payment method once your order is delivered. You don't need to do anything else.
Missed the first 10? With codes E50 and M2026, you still save $61 on the bundle.
New to Engines? You'll Feel at Home
A single carburetor feeds both cylinders, so you set one mixture and learn how the engine responds.
Electric start plus the 3-in-1 starter/ignition module: connect the battery, press the button.
The built-in water pump circulates coolant automatically. No extra pump to set up.
The Starter Kit brings the ignition, glow plugs, fuel and cooling parts together, so you don't have to hunt for compatible pieces.
Your First Start in 4 Easy Steps
- Build the engine. Follow the build video and the manual. The basic tool is included.
- Fit the Starter Kit. Install the glow plugs, fuel tank and line, water tank and pipes, and wire up the 3-in-1 module.
- Add battery and fuel. Use an 11.1V 3S LiPo with a T-plug and 25% nitro fuel.
- Press start. Then fine-tune the single carburetor as the engine warms up.
What You'll Receive & What You'll Need
You're getting the KIT version, so you build the engine yourself. The parts that make it run come in the Starter Kit. A quick check now means you'll have everything ready the day your engine is finished.
In the box
- ST-FL2 engine kit ×1
- Basic installation tool ×1
- Instruction manual ×1
You'll also need
- Starter / ignition / power module, F-type glow plugs ×2, fuel tank and fuel line, water tank and water pipes: all in the ST-FL2 Starter Kit
- 11.1V 3S LiPo battery with T-plug
- 25% nitro fuel
- A mounting base or stand for your setup
See How You'll Build It
Not sure if you can do it? Watch the whole build first. You'll follow the same steps with your own kit.
What You'll Love About It
Specifications
View full specifications
| Brand / Model | SEMTO ENGINE ST-FL2 |
|---|---|
| Version | KIT (assembly required) |
| Engine type | Nitro internal combustion, four-stroke |
| Cylinders | Inline twin |
| Displacement | 8.6cc (2 × 4.3cc) |
| Bore × stroke | 18.00 mm × 17.00 mm |
| Valve train | Single overhead camshaft (SOHC) |
| Power | 1.2 HP |
| RPM range | 3,000–20,000 rpm |
| Carburetor | Single |
| Cooling | Water cooling, built-in centrifugal water pump |
| Lubrication | Mixed / oil-mist lubrication |
| Starting | Electric start (480 brushed motor) |
| Glow plugs | F-type ×2 (included in Starter Kit) |
| Fuel | 25% nitro fuel |
| Material | CNC-machined aluminum, anodized |
| Engine size | 11.31 × 9.15 × 10.34 cm |
| Engine weight | 900 g |
| Package size / weight | 14.5 × 11 × 11.2 cm / 1,400 g |
| Recommended age | 16+ |
FAQ
How does the flash deal work?
Engine: enter code E50 at checkout and you pay $349.99 instead of $399.99. The code works on the engine only.
Starter Kit: enter code M2026 at checkout and you pay $98.99 instead of $109.99.
First 10 orders: once your order is delivered, we refund $20 for the engine, plus half of what you paid for the Starter Kit (about $49.50), to your original payment method.
Example: buy both and you pay $448.98 at checkout. If you're one of the first 10, you get $69.50 back, so the whole setup costs you $379.48.
Will the engine run straight out of the box?
No. This is a KIT version that you assemble, and the ignition, fuel and cooling parts are sold separately. The ST-FL2 Starter Kit covers those parts. You will also need an 11.1V 3S LiPo battery with a T-plug and 25% nitro fuel.
Is this a good first engine?
Yes. The ST-FL2 is one of our recommended first engines. It has a single carburetor to tune, push-button electric start, built-in water cooling, and a full assembly video to follow, so you can focus on learning how a four-stroke works rather than fighting the setup. Take your time with the manual during assembly and the first runs. See more starter options in our beginner engine collection.
Can I put it in an RC car?
It is designed with RC use in mind and leaves room for a clutch and transmission, which suits 1/8-scale builds. The clutch, transmission and mounts are not included, and fitting depends on your chassis.
Where can I find the manual?
A printed manual is in the box. You can also check our Download Manual page.
Safety notes
- Recommended for ages 16+. Younger builders should work with an adult.
- Run the engine outdoors or in a well-ventilated area, away from open flames.
- Nitro fuel is flammable. Store it sealed, away from heat and out of reach of children.
- The cylinder head and exhaust get hot during running. Let the engine cool before touching it.