2-stroke and 4-stroke are 2-wheeled off-road dirt bikes and you can ride them on the same terrain. The main difference between these two is the way they combust and operate.
The 2-stroke engine takes 2 stages to complete one power stroke, while the 4-stroke engine takes 4 stages to complete one power stroke.
A combustion cycle is a process in which the cylinder’s piston moves up and down to carry out the combustion cycle. While a stroke is a process where the piston moves from the center to the bottom of the cylinder.
The piston in its one stroke goes down, grabs air and gas, moves back up and the exhaust valve opens to expel the exhaust. In two-stroke dirt bikes, the engine delivers more functions in one piston movement while in 4-stroke dirt bikes the 4 events complete the power cycle.
What Does 4-Stroke Mean?
In 4-stroke dirt bikes, it takes 4 crankshaft revolutions to complete one exhaust and combustion cycle.
4-stroke dirt bikes are easier to learn about and experienced and serious riders prefer 4-stroke dirt bikes. However, these dirt bikes are less fun to ride when compared with the nostalgia of 2-stroke dirt bikes.
Top Features Of 4-Stroke Dirt Bikes
- The piston size of a 4-stroke dirt bike is larger than that of a 2-stroke dirt bike of the same classification.
- A 4-stroke dirt bike has more electric capabilities with more electronic switches. It enables a better starting program, a good traction control. While in 2-stroke you don’t have any buttons. There is just a kill switch and a kick to start a dirt bike.
- These bikes are now being built with modern technology and better suspension. Also, the 4-stroke dirt bikes are bigger and heavier, making you feel like you are sticking more to the ground.
- Therefore, when it comes to a relaxed ride, 4-strokes are the best. 2-strokes dirt bikes make it more exhausting for longer rides and races
- With less room in the engine bay, these dirt bikes are more complicated to work on. More parts are equipped on this dirt bike allowing little space. More expensive to buy, work on, and maintain. A 2-stroke dirt bike costs you $700 while a 4-stroke dirt bike of the same classification costs $10,000 and above.
What Does 2-Stroke Mean?
In a 2-stroke dirt bike, 2-crankshaft revolutions complete one combustion cycle. Unlike 4-stroke dirt bikes, 2-stroke dirt bike, generates twice much power as the 4-stroke dirt bike of the same classification.
In a 2-stroke engine, the piston goes up and down, making a 2-stroke movement to complete a full cycle of intake, combustion, and exhaust. A 2-stroke engine is simpler and lighter than a 4-stroke engine as it does not have a complicated camshaft, timing chain, and cylinder head with valves.
Top Features Of 2-Stroke Dirt Bikes
- A 2-stroke dirt bike sounds really good on a track.
- These dirt bikes have steep power curves, making them a little more difficult and exhausting to ride.
- Has a much larger expansion chamber (or head pipe) that comes right out of the cylinder.
- More clutch is required for a 2-stroke dirt bike as compared to a 4-stroke bike. On a 4-stroke dirt bike, the power is linear while on a 2-stroke you need a clutch to maintain those RPMs.
- More room in the engine bay, no camshafts, and timing chains, making them easier to work on.
- With fewer moving parts and less stuff to wear out, these dirt bikes are easier and cheaper to maintain. They are also cheaper to buy and good for those with limited budgets.
- Less electronic capabilities and lighter in weight. Less planted to the ground and less stable to ride.
- The lighter weight, no valves, camshafts, no chains to drive, make them way more powerful than 4-stroke dirt bikes.
What’s Easier to Ride out of 2-Stroke and 4-Stroke?
When it comes to the ease of ride, these bikes deliver disparately on different tracks and riders prefer them according to their choice.
Racing
A 2-stroke dirt bike is designed to be compatible with technical landscape riding. While 4-stroke dirt bikes are easier to ride on fast and open tracks. Also, 2-stroke dirt bikes are suitable for experienced and skilled racers and 4-stroke dirt bikes go well with novice racers.
Trail Riding
A 4-stroke dirt bike with its broad powerband is more predictable, making it smoother and easier to control for trail riding. Especially if you are a beginner in trail riding, go for a 4-stroke dirt bike.
Off-Road Riding
2-stroke dirt bikes with their smaller body, lighter weight, and more power per unit of displacement are best for off-road riding.
What’s Faster out of a 2-stroke and a 4-stroke Dirt Bike?
A 2-stroke dirt bike is faster than a 4-stroke dirt bike of the same classification. And here are the factors that make it faster
- A 2-stroke bike has two main functions of compression and combustion as compared to a 4-stroke dirt bike which works on four main functions including compression, induction, ignition, and exhaust.
- The per minute revolution of an engine of a 2-stroke dirt bike is much faster than a 4-stroke dirt bike of the same engine displacement.
- A 4-stroke dirt bike generates power in two crankshaft revolutions with the piston moving twice upwards and twice downwards while in 2-stroke dirt bikes a single crankshaft moves.
4-stroke Dirt Bike Benefits
Not only beginners but experienced riders also prefer 4-stroke dirt bikes due to their following benefits.
Wider Powerband
The 4-stroke bikes are built to deliver a wider range of speeds means they have wider power bands for effective braking, clutching, and shifting.
More Fuel Efficient
When compared with a 2-stroke engine, a 4-stroke dirt bike is more efficient in terms of fuel economy. The 4-stroke engine comprises valves that eliminate any air-fuel loss, giving more gas mileage.
Steady Power Output
4-stroke dirt bikes offer more steady power output which makes them more reliable and safe to ride. Riders who take long routes prefer 4-stroke dirt bikes for longer-lasting engines.
Quieter And Smoother Operation
The engine of 4-stroke dirt bikes has half as many explosions per RPM cycle as 2-stroke bikes that run at higher RPMs and produce more noise. Also, these bikes are equipped with exhaust and intake valves, making them quieter and smoother to ride.
Easier To Ride For Beginners
With its heavier and stable body, steady and reliable power output, wider powerband, and less-exhausting features, a 4-stroke dirt bike is easier to ride and control for beginners.
Environmental Friendly
According to emission testing rules, since 4-stroke dirt bikes do not mix oil with fuel to run engines, they deliver clean burning engines which makes them environmentally friendly. Also because of their quieter output, they are best to reduce noise pollution.
2-Stroke Dirt Bike Dominance
Perfect for off-road riding, 2-stroke dirt bikes are dominant, and here’s the reason
Lighter Weight
2-stroke dirt bikes with their lighter bodies are more agile on tight and technical terrains. These bikes also give better acceleration and handling due to their lightweight components.
More Powerful Engine
2-stroke dirt bikes have the benefits of hitting hard and fast on the track. With their explosive power output, 2-stroke dirt bikes are preferred by extreme ride lovers.
Easy To Maintain
A 2-stroke comprises almost 50% fewer components and this simplified structure makes them easy to maintain. These bikes are also easier to repair than 4-stroke dirt bikes.
Generally Faster
A 2-stroke engine exhibits intense kick on the motor and revs much quicker than a 4-stroke dirt bike of the same displacement making them faster than the later ones.
Less Complex Design
The less complex design, fewer parts to work, and less prone to wear make 2-stroke dirt bikes a good choice for riders who prefer to have less up-keep required dirt bikes.
Two-stroke Dirt Bike Challenges
- 2-stroke dirt bike engines don’t last as long as 4-stroke engines and are less fuel efficient.
- 2-stroke dirt bikes have higher fuel consumption and release emissions into the air, creating the Green House Gas effect. These bikes are therefore not environmentally friendly and are strongly opposed by EPA.
- As for their power output and fast speed, these dirt bikes can be more difficult to ride for beginners.
- Though 2-stroke bikes have fewer parts, they require more frequent maintenance.
4-stroke Dirt Bike Challenges
- The complex and heavier body of these dirt bikes makes them less agile to ride.
- Though they have a smoother and steadier engine, their less power output is a major drawback in 4-stroke dirt bikes.
- These bikes have more complex parts, which are costly and difficult to maintain.
- 4-stroke dirt bikes are way more expensive to buy and maintain than 2-stroke dirt bikes.
Review of the Best 2-Stroke Dirt Bikes
- Yamaha YZ250
Launched in 1974 and with its first update in 2015, the 2-stroke Yamaha YZ250 is equipped with a fast and powerful engine. This bike offers improved ergonomics and better control, making it a perfect choice for next-level agility lovers.
- KTM 250SX
It is a user-friendly 2-stroke dirt bike that satisfies the power intent of both novice and skilled riders. The hand-adjustable dual compression control allows you to adjust high and low speeds in seconds. While the expertly crafted shock absorbers make your ride less hard and less fatigued.
- Husqvarna TC250
The light weight of just 23.9 kgs and the Electronic Fuel Injection technology make Husqvarna TC250 a faster, yet controllable 2-stroke dirt bike. This bike performs best for extended periods of time and the air filters allow a maximum flow of clean air to give a constant and reliable speed.
Review Of Best 4-Stroke Dirt Bikes
- KTM 450 SX-F
KTM 450 SX-F with its effective throttle response and power band delivers consistent and linear power. The KTM 450 SX-F has a five-speed gearbox with good spacing. It also offers one of the best powerbands and proven reliability in the market.
- Honda CRF450R
The Honda CRF450R comes with a monstrous motor and lower to mid-range torque giving faster corner existence. It also gives riders an optimized suspension performance and better stability. The Honda CRF450R comprises a stronger muffler and a special air filter air box for more torque.
- Yamaha YZ450F
Despite being a 4-stroke dirt bike, the Yamaha YZ450F is lighter, faster, and more powerful than all others of its kind. Its stronger and linear power gives absolute control to the riders.
It is also built with a lightweight aluminum frame and an upgraded KYB suspension to help you to stay ahead of your competitors.
Here’s a table depicting a brief comparison of the top 2-stroke and 4-stroke dirt bikes.
| Bike’s Model | Weight | Torque | HP | Top Speed | Fuel Capacity |
| 2-Stroke Dirt Bikes | |||||
| Yamaha YZ250 | 227 lbs | 41.5 Nm | 48.8 | 75 mph | 1.6 gals |
| KTM 250SX | 57.5 lbs | 24 Nm | 53 | 80 mph | 1.98 gals |
| Husqvarna TC250 | 23.9 kg | 19.3 lb-ft | 32.5 | 120 kmh | 1.9 gals |
| 4-Stroke Dirt Bikes | |||||
| KTM 450 SX-F | 239 lbs | 33.4 lb-ft | 63 | 85 mph | 1.85 gals |
| HondaCRF450R | 244 lbs | 35.1 lb-ft | 55.2 | 90 mph | 1.70 gals |
| YamahaYZ450F | 242 lbs | 35.37 lb-ft | 59.29 | 75-85 mph | 1.6 gals |
Conclusion
It’s true that 2-stroke and 4-stroke dirt bikes have pros and cons to ride. Yet, the best choice to buy ultimately comes down to your personal preference and riding style. That’s why to consider the benefits and challenges outlined in this article, as well as the top 3 recommended dirt bikes when making your decision.
Reference
13 Things to Know about a 4-stroke dirt bike
13-things to know about a 2-stroke dirt bike
