Product details
Give Your RC Car Its First Real 2-Cylinder Engine
If you want a real nitro engine in your RC car, the SEMTO ST-FL2 gives you the most power for your money: 1.2 PS from a water-cooled 8.6cc 2-cylinder that fits 1/8-scale cars.
Pre-Order Now · $349.99 with Code E50Already own an NR200? The SEMTO ST-FL2 is its upgraded successor.
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.
- Own an NR200? Add your NR200 order number in the order note and we'll include 2 free F-type glow plugs.
Missed the first 10? With codes E50 and M2026, you still save $61 on the bundle.
Why RC Car Fans Choose the SEMTO ST-FL2
Two cylinders firing in turn give it the deep, even rumble of a real car engine, not the buzz of a single-cylinder nitro.
1.2 PS from a water-cooled 8.6cc moves a real 1/8-scale car, even a heavier one, instead of just running on a stand.
Water cooling keeps the temperature steady, so you can keep driving instead of stopping to let the engine cool down.
Better-oiled connecting rods and an adjustable belt fix the two problems that most often stop engines like this.
The starter motor goes on either side and the engine is compact and light, so you spend less time making custom brackets.
The connecting rods come out without stripping the engine, and spare parts are in stock. No sending the engine away for repair.
On a tighter budget? The air-cooled SEMTO ST-NF2 starts at $199.99 and is a great first engine.
See It on the Road
Curious how this engine layout handles in a real RC car? Here's the NR200, the model the SEMTO ST-FL2 is built on, on the dyno, at full revs and out on the road, tested by YouTuber JohnnyQ90. The SEMTO ST-FL2 adds more power and new upgrades on top.
Video shows the NR200, predecessor of the SEMTO ST-FL2.
A Closer Look
1.2 PS from 8.6cc gives you about twice the power of the air-cooled SEMTO ST-NF2, so heavier 1/8-scale cars still feel lively.
A built-in water pump circulates coolant through an 80 mm radiator, so the engine keeps a steady temperature lap after lap.
At about 700 g, it suits 1/8-scale builds, and the starter motor mounts on the left or right side.
Clear parts layout and easy-to-reach components make adjustments and repairs in your car quicker.
Already own an NR200? See everything that's new in the SEMTO ST-FL2.
Build It Yourself. Start It with One Push.
Ever wondered what it feels like to build a real engine from scratch? Here's your chance. Every part goes together step by step, with a clear manual and a full video tutorial to follow along. Never built an engine before? No problem. First-timers get it running too.
And when the last bolt is in? Just connect the battery and press the button. No pull cord, no starter box, no fuss. That first start, from an engine put together with your own hands, is the best part of the whole project.
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.
In the box
- ST-FL2 engine kit ×1
- Basic installation tool ×1
- Instruction manual ×1
You'll also need
- The ST-FL2 Starter Kit: 3-in-1 module, 2 F-type glow plugs, fuel tank and fuel line, water tank and hoses, 80 mm radiator
- An 80 mm cooling fan for the radiator
- 11.1V 3S LiPo battery with T-plug
- 20–25% nitro fuel
- A mounting base or stand for your setup
Specifications
View full specifications
| Brand / Model | SEMTO ENGINE ST-FL2 |
|---|---|
| Version | KIT (assembly required) |
| Engine type | Nitro internal combustion, 4-stroke |
| Cylinders | Inline twin |
| Displacement | 8.6cc (2 × 4.3cc) |
| Bore × stroke | 18 mm × 17 mm |
| Valve train | Single overhead camshaft (SOHC) |
| Power | 1.2 PS |
| RPM range | 2,000–18,000 rpm |
| Carburetor | Single |
| Cooling | Water cooling, built-in centrifugal water pump (80 mm radiator and fan required) |
| Lubrication | Splash lubrication |
| Starting | Electric start, 480 brushed motor (11.1V 3S LiPo, 12V max) |
| Glow plugs | F-type 4-stroke ×2 (included in Starter Kit) |
| Belts | B107-7 MXL timing belt, B92-6 MXL starter belt |
| Fuel | 20–25% nitro fuel |
| Material | CNC-machined aluminum, anodized |
| Engine size | 104 × 98.2 × 96.8 mm (about 143 mm wide including exhaust and starter motor) |
| Engine weight | 700 g |
| Package size / weight | 14.5 × 11 × 11.2 cm / 1,400 g |
| Recommended age | 16+ |
FAQ
How does the pre-order 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.
When will the SEMTO ST-FL2 ship?
The SEMTO ST-FL2 is on pre-order now, with shipping expected from mid-November 2026.
Is the SEMTO ST-FL2 a good first engine?
It can be, if you're patient and follow the assembly video and manual. But if this is your very first running engine, the SEMTO ST-NF2 is simpler to set up and costs less. The ST-FL2 adds water cooling and about twice the power, which makes it the better pick for RC builds and for your second engine. Compare the ST-FL2 and ST-NF2.
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 in the ST-FL2 Starter Kit. You will also need an 80 mm radiator fan, an 11.1V 3S LiPo battery with a T-plug and 20–25% nitro fuel.
Can I put it in an RC car?
Yes. It was developed with 1/8-scale RC cars in mind and leaves room for a clutch and transmission. A dedicated SEMTO ST-FL2 clutch is in development. The clutch, transmission and mounts are not included, and fitting depends on your chassis.
Is there a gasoline version?
No. The SEMTO ST-FL2 is a nitro engine. If you prefer gasoline, the SEMTO ST-NF2 comes in a gasoline version.
Where can I find the manual and more answers?
A printed manual is in the box, and you can also find it on our Download Manual page. For setup, carburetor tuning, belt tension and troubleshooting, see the SEMTO ST-FL2 FAQ.
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 toxic and 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.