For riders seeking an affordable horsepower boost, a 2-stroke NOS kit can deliver noticeable performance gains. This guide highlights five NOS options that target 2-stroke and small-displacement bikes, including pocket bikes and street-legal models. These kits are best for riders who want faster throttle response, stronger mid-range torque, and a straightforward install. The top picks are suitable for racers, hobbyists, and enthusiasts who prefer simple, responsive power increases without expensive upgrades.
| Product | Brand |
|---|---|
| Small Engine Nitrous Oxide Kit 250-500 2 & 4 Stroke, EFI & Carb | 6 Sigma |
| Moto GP 2 Stroke Pocket Bike 49 50 cc NOS Nitro Nitrous Oxide Kit Boost Bottle | 6 Sigma |
| MSX125 Grom 125 Performance NOS Nitrous Oxide Kit Stage 1-5 | 6 Sigma |
| Suzuki TU 250 Grass Tracker Big Boy Volty NOS Nitrous Oxide Kit & Boost Bottle | 6 Sigma |
| Yamaha YFM 80 R Raptor NOS Nitrous Oxide Kit & Boost Bottle | 6 Sigma |
Small Engine Nitrous Oxide Kit 250-500 2 & 4 Stroke
NOS is presented here as a straightforward horsepower boost for eligible engines. The kit is designed to increase peak horsepower by about 20% at wide-open throttle and to improve low-end torque, aiding acceleration. Best for riders with EFI or carbureted 2-stroke or 4-stroke small engines seeking a simple performance upgrade.
Best for: Enthusiasts seeking a broad, transferable boost for various small engines. Why selected: It claims a balanced gain across high and low RPM ranges, with a focus on noticeable throttle response.
Caution: Limited data on long-term reliability; verify compatibility with your specific carburetion or EFI setup before purchase.
Moto GP 2 Stroke Pocket Bike 49 50 cc NOS Kit
Designed for pocket bikes with 49/50 cc displacement, this NOS kit targets fast throttle response and a higher peak horsepower. It is best for riders who want a compact system that delivers tangible performance on small-displacement machines.
Best for: Pocket bike riders and mini racer enthusiasts. Why selected: Specifically sized for smaller engines, with similar 20% peak horsepower gains as listed for larger kits.
Caution: The compact nature may limit compatibility to certain frame types or intake configurations; confirm mounting and line routing for your pocket bike model.
MSX125 Grom 125 Performance NOS Kit Stage 1-5
This option targets a popular small-displacement street bike. It emphasizes a noticeable mid-range improvement and a consistent torque increase across RPMs. Stage 1–5 variants offer progressive tuning options for riders who want to ease into NOS power or push for higher power levels.
Best for: Honda Grom or MSX125 owners seeking a scalable NOS upgrade. Why selected: It provides a staged approach to horsepower gains, aligning with common user goals like improved acceleration and throttle response.
Caution: Similar to other NOS kits, driving style and engine condition influence results; avoid aggressive testing without proper safety precautions and tuning.
Suzuki TU 250 Grass Tracker Big Boy Volty NOS Kit
Designated for a lightly larger displacement twin or single-cylinder setup, this NOS kit focuses on delivering a stronger peak power boost with emphasis on improved acceleration at higher RPMs. A practical choice for riders looking for a robust upgrade on a classic small-combat bike.
Best for: Suzuki TU 250 Grass Tracker and similar small twins. Why selected: It targets a balance of peak horsepower and mid-range torque for street performance.
Caution: Ensure alignment with intake configuration and exhaust flow; improper installation can affect performance gains.
Yamaha YFM 80 R Raptor NOS Kit
Targeted at a youth- or entry-level performance segment, this kit claims increased horsepower and improved mid-range torque. It is best for riders seeking a straightforward upgrade on smaller Yamaha platforms with a focus on responsiveness rather than max power output.
Best for: Youth or beginner riders looking for a noticeable, safe throttle upgrade. Why selected: Combines a simple install with scalable horsepower gains appropriate for smaller displacement bikes.
Caution: Ensure correct model pairing and safety considerations for smaller displacement engines; verify compatibility before installation.
Yamaha YFM 250 R Raptor NOS Kit
This kit is designed for a larger Raptor variant, offering a higher capacity option for owners seeking more substantial horsepower gains. It emphasizes peak horsepower improvements and responsive torque in the lower-to-mid RPM range.
Best for: Yamaha YFM 250 R owners wanting a stronger performance push. Why selected: It aligns with larger displacement projects while staying within the NOS upgrade concept.
Caution: Higher power outputs require careful tuning and safety-focused adjustments to other supporting systems (fuel, ignition, cooling). Avoid aftermarket mismatches.
Buying Guide
What to consider before buying a 2-stroke NOS kit
- Engine compatibility: Confirm displacement, carburetion vs. EFI, and intake configuration. Some kits are optimized for specific models.
- Power goals: Decide whether you want a modest torque boost or a higher peak horsepower gain. Kits are marketed with varying upgrade levels.
- Installation scope: Assess whether the kit requires professional installation, additional hardware, or engine tuning.
- Safety and rules: NOS creates higher pressures and requires safe handling, especially on street-legal machines and youth models.
- Suspension and drivetrain: Consider upgrading supporting components if pursuing significant horsepower gains to maintain control and traction.
Comparison at a glance
- Best for broad compatibility: Small Engine Nitrous Oxide Kit 250-500 2 & 4 Stroke
- Better for pocket bikes: Moto GP 2 Stroke Pocket Bike 49 50 cc NOS
- Best phased approach: MSX125 Grom 125 Performance NOS Kit Stage 1-5
- Best for classic small twins: Suzuki TU 250 Grass Tracker Big Boy Volty NOS
- Best for youth bikes: Yamaha YFM 80 R Raptor NOS Kit
FAQ
- Q: Do NOS kits work on both 2-stroke and 4-stroke engines? A: Yes, but compatibility depends on the kit’s design and the engine’s fueling system.
- Q: Will NOS increase engine reliability? A: NOS can improve performance but should be installed correctly; improper setup may affect reliability.
- Q: Is professional tuning required after installation? A: Often, yes, to ensure safe operation and to optimize gains for your specific engine.
- Q: Are NOS gains the same across all models? A: Gains depend on engine displacement, intake, and exhaust; 20% peak horsepower is a common marketing target but results vary.
- Q: What safety measures should I take? A: Use proper safety gear, follow manufacturer guidelines, and avoid high-risk operation until you are familiar with the system.
- Q: Can I use NOS on a street-legal bike? A: It is possible where laws and vehicle specifications permit this upgrade; verify local regulations and vehicle compliance.