Menu

Two-stroke motorcycles are some of the most iconic and well-known motorcycles of all time. They are pillars of global and British motorcycling history. Knowing the history and key facts about two stroke motorcycles is therefore essential for any motorcycle fan.

In this article, we'll explain exactly what makes these thrilling bikes tick and what does 2-stroke mean. Whilst celebrating some of the most famous models, we'll let you know the benefits and drawbacks of two-strokes. This will help you make an informed decision if you're thinking of buying your very own stroker.


What Is A Two-Stroke Motorcycle?

A two-stroke motorcycle is one fitted with a 2-stroke engine. These motorcycles had their golden years in the 1970s and 1980s but began their decline in 1984. Despite this, 2-stroke motorcycles continue to be well-loved. They became popular as collectables as the years go by.

These classic motorcycles are louder, more powerful, and lighter than modern four-stroke engines. It's these factors that have made them so popular. Many motorcycle fanatics pay a lot of money for some of the most famous vintage models.

A two-stroke engine gets its name from the dual compression stroke that the piston performs every cycle. During this cycle, a 2-stroke completes the whole process of intake, air compression, and combustion. This is why 2-strokes can output so much power (a four-stroke takes twice as long to complete every cycle).

This incredible level of power has contributed to the racing pedigree of these bikes. Even when banned from road use, they were still used on the race track with fast 500cc two-stroke bikes racing against 1000cc four-stroke models!


Why Were 2-Stroke Engines Banned from Road Use?

In 1984, the sale of two-stroke cars and motorcycles was banned in the USA. The reasoning for the ban was the tightening of emissions regulations on vehicles. Two-strokes couldn't be modified to reduce their emissions to an acceptable standard, therefore they were no longer road legal.

The UK followed suit in 2004 when 2-stroke engines were relegated for use with low cc scooters only. By this point, two-stroke motorcycles had become difficult to find. Manufacturers had ditched the format after the US ban.

The introduction of four-stroke motorcycles brought a range of advantages. These included warmer engine sounds, modern features and, of course, lower emissions. Still, there is nothing quite like heading for the open road, and opening up the throttle of a two-stroke racer.


A Brief History Of Two-Stroke Motorcycles

The history of the two-stroke bike can be traced to 1904. In this year, manufacturer Scott patented the first 2-stroke motorcycle engine. In 1908, the company began producing twin-cylinder water-cooled motorbikes. This was recognised as the first proper use of a 2-stroke engine.

Two-stroke motorcycles grew in popularity over the following decades. But, it wasn't until the 1960s and 70s that these road legal racers were made on an industrial scale. Modern technology allowed manufacturers to build this simple 2-stroke motor quicker and cheaper.

Over the years, the main drawback of this basic design became obvious - they were thirsty. The fuel consumption made them expensive and harmful to the environment.


Types Of Two-Stroke Motorcycles

One-cylinder

Single-cylinder-head engines were the most affordable variation of the 2-stroke machines. These models are still found for bargain prices and are a great way to get into the two-stroke world. Iconic one-cylinder bikes such as the Hodaka Ace 100 and Yamaha DT-1 do have higher price tags though.

Single-cylinder bikes were available in a wide range of capacities. The two stroke engines stretched from 50cc all the way up to 400cc. They were designed for every discipline - street, track, and dirt. One-cylinders summed up the thrilling simplicity that strokers became known for.

Two-cylinder

In the 1960s, manufacturers began producing motorcycles with two-cylinder engines. These engines were more expensive and complicated to build than one-cylinders. On the flip side, they were more durable and created less vibration.

Double-cylinder engines were used in some of the most famous motorcycles of the period. The Yamaha RD350 is a firm fan favourite and has a cult following across the world. In fact, the Yamaha RD series arguably became the most iconic group of two-stroke bikes ever!

The position of the two cylinders varied from maker to maker. Majority of models had parallel twin, where cylinders were placed next to each other. However there were others such as the Italian motorcycle makers Moto Morini, who prefered the V twin design for their 350cc & 500cc motorbikes.

The introduction of two-cylinder engines brought some important performance improvements to these bikes. These improvements didn't sacrifice any of the exciting characteristics found in single-cylinders.


Three-cylinder

Another type of motorcycle made during the two-stroke era was the three-cylinder. The three-cylinders represented the peak of 2-stroke engineering and were expensive to produce. The benefits of three cylinders included lower fuel consumption extra throttle power.

Three-cylinders were never as popular as two-cylinders due to their higher price points. The Kawasaki H1 and H2 and the Suzuki GT series are some of the most well-known three-cylinder 2-strokes.

Today, the three-cylinder is remembered as the most advanced and technical form of the two-stroker. As a result, prices can get very high for the big models - the Kawasaki H1 often sells for close to $20,000 USD!

Advantages Of Two-Stroke Bikes

Let's take a closer look at some of the advantages of these legendary motorcycles to see what made them tick:

Consistent power output

In a two-stroke engine, every other piston movement is a power stroke. With a four-stroke engine, you only get one power stroke every four-strokes. As a result, the former offers a more linear and reliable power output.

More frequent combustion comes with its disadvantages. This is particularly true when it comes to fuel consumption. We'll discuss this more later on.

Rapid acceleration

Thanks to quicker combustion and faster power output, two-stroke motorcycles have incredible acceleration. Nearly everyone who gets on this road legal racer is immediately blown away by how quickly these machines can get up to speed.

This feeling is quite addictive. It is why many motorcycle fans become obsessed with this type of bike.

High top speed

Quick acceleration would be no use if there wasn't speed to match. Luckily for us, 2-stroke bikes can really shift. Some of the most powerful racers could get within touching distance of 150mph.

You only need to look at the rich pedigree of race track motorcycles to understand what they have to offer. Riding a stroker is a thrill like no other. It's something that has to be experienced for yourself to appreciate.

Roaring sound

Another legendary feature of two-stroke motorycles is their instantly recognisable sound. The unique engine and exhaust port design created a louder and more piercing sound than four-strokes. If someone's approaching you on a 2-stroker, you'll definitely know about it!

Cheap to manufacture

The two-stroke had a straightforward design, which also means that it was relatively cheap to manufacture. This benefited the consumer, too. They were affordable - especially the single and double-cylinder designs.

Simple to repair

The other benefit of these bikes' simplicity was that they were easy to repair. Parts were readily available, sometimes interchangable between models and could be swapped in with hardly any trouble.

Modification and customisation of these simple machines was popular in past and continues to the present. Finding an original two-stroke is almost imposible, many bikers have modified their beloved models to create café racers and custom sports bikes.

Drawbacks Of Two-Stroke Bikes

As we've already explained in this article, two-strokes weren't without their drawbacks. Let's investigate a few of the disadvantages:

High emissions

The biggest drawback of two-strokes was the reason that they were eventually banned from sale - high emissions. Since the engines are combusting at twice the rate of four-strokes, they use more fuel over a given period. As emissions standards were slowly tightened, strokers eventually became one of their victims.

Additionally, the high fuel usage also means the bikes fuel tank will empty faster than their four-stroke cousins. This can be a big problem if you use your motorbike for long road trips or journeys.

Less durable

Even though two-strokes are cheaper to produce and repair than four, they are also less durable. The lubrication system is not as effective on two-strokes. This means extra friction is produced, and parts wear down faster.

Expensive oil

The final disadvantage is that engine oil can be quite expensive, particularly if you're buying a quality product. Some earlier models, such as Yamaha, didn't require pre-mixed oil due to separate oil pump. However for others, the cost of fuel mixing is always something you should be taking into account when buying a stroker.

Examples of Classic Two-Stroke Motorbikes

There were hundreds of motorbike models manufactured during the two-stroke golden age. Manufacturers were always trying to improve performance and squeeze potential out of the simple 2-stroke engine design. This resulted in plenty of interesting bikes.

Only a few models went on to achieve legendary status. Here are some of the most iconic strokes from the street and track:

Yamaha RD350

You can't have a conversation about two-strokes without discussing the Yamaha RD350 (or the 250cc version). This classic street bike, and the RD series, is a beautiful combination of all the amazing 2-stroke features. It offered a quick-handling, noisy and lightning-fast ride.

The original version of RD350 was produced between 1973 and 1975. With air cooling, a six-speed gearbox, and a reed valve-equipped intake tract, this machine was packed with modern features. Despite being a two-stroke, the RD350 was also fitted with oil injection. This meant users no longer had to mix their oil and fuel themselves.

Statistically, the Yamaha RD350 competed with the very best two-strokes of the day. Its 347cc engine produced 39 bhp, which pushed the RD350's top speed to a staggering 105 mph. These numbers meant the Yamaha machines became an instant racing success.

The Yamaha RD350 production continued successfully for decades to come, with several improvements such as the liquid cooling or YPVS engine. There are still regular RD350 track meets to this day.

If you're looking for a pure two-stroke experience, then you'll struggle to find anything better than an RD350. Be aware, though, this motorbike is sought after - and the price reflect the demand.

Kawasaki 500 H1

Many people consider the Kawasaki H1 to be the pinacle of two-strokers. With a 3-cylinder engine, the 500 H1 was technologically advanced. It required a more complex production process to construct.

3-cylinder engines brought new and unique characteristics to two-stroke bikes. They did this without giving up any of the excitement. People who owned a 3-cylinder could expect a smoother experience. Better fuel usage and less frame vibration were key features.

The 500 H1 used the 3-cylinder setup to its advantage and produced an impressive 60 bhp. This granted the bike a rapid top speed of 124 mph and a 13-second standing quarter mile. These were some serious statistics. Because of this, the Kawasaki H1 was often used by drag racers to create some bespoke custom motorbikes.

The 500 H1 is the perfect choice for anyone who's after a top-of-the-line 2-stroke model. It has amazing features and incredible power to weight ratio. If you are interested in this bike, it's also worth investigating the similar Kawasaki 500 H2.

Suzuki RG500 Gamma

The RG500, sometimes known as the Suzuki "Gamma", was the manufacturer's flagship racing motorbike from 1985 to 1987. The bike was an updated version of the 1984 RG500 used by world champion Franco Uncini in the '84 Moto GP season.

It's hard not to fall in love with the RG500 as soon as you see it. The bike is truly stunning, with aerodynamic bodywork and a classic 80s design. For its size, the Gamma was also very lightweight and offered responsive handling.

Even though the RG500 Gamma was designed as a street bike, it took plenty of design cues from its racing ancestors. The massive 498cc engine was liquid-cooled and powered by a chunky 4-cylinder setup. This produced an impressive 95 bhp. When you shifted the gears, the bike could reach an eye-watering top speed of 146 mph.

The combination of the RG500's power delivery and ultra-lightweight nature made it a two-stroke icon. Be prepared to pay if you want one, though; the RG500 Gamma doesn't come cheap these days!

FAQs

Can you still buy two-stroke motorbikes?

Since 2-stroke motorbikes were banned in the UK in 2004, you can't buy them new. This doesn't mean you can't ride one, though. There is a thriving vintage market for these classic bikes and spare parts.

If you are thinking about picking up a two-stroke bike and making it street legal, then it's essential that you know about their drawbacks. The biggest one is the amount of fuel they consume. Two-strokes operate twice as fast as four-strokes and are more expensive to run.

Despite these issues, two-strokes offer an experience like no other. If you're a thrill-seeker or someone who wants to get back to motorcycle basics, you'll have a blast on a two-stroke bike.

Are two-stroke motorbikes and parts expensive?

When two-strokes were being mass-manufactured, they were the cheapest type of motorbike. This was thanks to their straightforward engine setup. Following the ban of road-going strokers, the demand has gone up considerably.

Despite the increase in demand, prices haven't skyrocketed. There are still plenty of deals to be had, even on the most popular models. Make sure to shop around and do your research before spending lots of cash on a vintage two-stroke.

Two-stroke bikes are generally considered less durable than four-strokes. This means you'll likely end up having to replace parts more often. Some parts are readily available, especially for the more common models, but some you might have trouble sourcing out. So do your homework first!

Do two-stroke motorbikes need fuel mixing?

Yes, many two-stroke motorcycles require the fuel and oil to be mixed before ignition. Although some bikes have built-in oil injection, many need mixing in the fuel tank. This might sound like a bit of a headache, but in reality, you get used to the process.

The exact ratio of fuel to oil you'll need depends on the motorbike you have, but it's typically between 32:1 and 40:1. It's important to get your ratio as accurate as possible. Too little oil and you'll start to damage the engine, too much, and the engine won't run.

We always recommend using high-quality oil if you can. This will ensure that your engine stays in great condition. It will keep your bike running for years to come.

What's the difference between one-cylinder and two-cylinder two-strokes?

The simplest type of two-stroke engine is the one-cylinder. This type of engine was easy to build and was the cheapest two-stroke option. Two-cylinder engines were developed later and brought better performance. That said, they were more complex and heavier once installed.

Some of the advantages of two-cylinders include less vibration and quicker throttle response. One-cylinder engines have better fuel efficiency, simpler cooling systems, and easier maintenance.

In truth, the number of cylinders isn't going to be a deciding factor when choosing which bike to buy. It's still important to understand how the cylinders affect the performance of a bike. You can find out more about this topic in the "Types Of Two-Stroke Motorbikes" section above.


What do you love about Two-stroke motorcycles?

3 comments
Alyn Scott
Alyn Scott
Sunday 05th December 2021

My Kawasaki kh250 was a hooligan of a bike. It surprised many much bigger bikes. Smoked like hell though.

Jim Delaney
Jim Delaney
Friday 19th November 2021

For those of us who grew up with them 2 strokes are in the blood. In reality owning a 4 stroke or two for general use and the smokers for fun days makes it all work. It is fairly common for people to approach me at cafes to want to talk about what ever 2 stroke I may have parked out front. They evoke memories!

Jim Ford
Jim Ford
Wednesday 01st December 2021

I had a 1929 500cc Scott. It was a wonderful machine and I wish I still had it! It. It wasn't fast but had loads of character. The manual advance and retard meant that it could tick over steadily like a four stroke, without the typical 'pop popping' of a two stroke. Best bike I ever had!

David Piggott
David Piggott
Tuesday 14th September 2021

Hi find your Little gem is very interesting makes good read why have you not done a book ?

Jackie
Jackie
Wednesday 15th September 2021

Hello David,
Thank you for the compliments and suggestion! I think there is still a lot I need to learn about the world of motorcycles. However, it is encouraging to know that you enjoy my blogs :)
Once again, thank you!

Showing 1 to 1 of 3 (1 Pages)
Leave a comment
Note: HTML is not translated!
You might also like

The product is currently Out-of-Stock. Enter your email address below and we will notify you as soon as the product is available.

Name
Email