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It’s a somewhat controversial thing that’s talked about a lot, but what does it mean to “derestrict” a 50cc scooter (or moped, for that matter)?

And if you’re interested in trying it out for yourself, how is it done?

Tune in to discover:

  • What “derestriction” actually means
  • Why 50cc scooters are restricted (and not their 125cc or 250+ counterparts)
  • 2 examples of derestriction methods
  • Something CRUCIAL you must know if you’re going to do this


Hello, and welcome to another episode of 30-minute motorcycling – a podcast for those riders who are at the beginning of their own Dual Wheel Journey, where you’ll discover something new about how your motorcycle, moped, or scooter works – in less than 30 minutes.


And this episode is dedicated to 50 cc scooters. Did you know that despite their small engine size, they’re actually capable of higher speeds than 45 km/h or 30 miles per hour?

No, really, it’s true – as long as they’re derestricted, which we’ll talk more about in this episode.


We’re going to talk about:

  • What the term “derestriction” means
  • Why 50cc scooters have this restriction
  • 2 common ways to derestrict a scooter
  • And of course, a not-so-fun, but nevertheless CRUCIAL thing to remember


But first, let’s start at the beginning – it’s talked about a lot, but what does it actually mean to “derestict” a 50cc scooter?


As I mentioned earlier, scooters that belong to the 50cc engine class are restricted to a certain top speed. Once it reaches this speed, it won’t go any faster – at least not by its own steam.


Therefore, to “derestrict” a scooter means to remove any mechanism that limits the top speed.


But why is the 50cc engine class subjected to so much restriction?


Well, it all comes down to one thing – legality. Unlike bikes with 250cc or even 125cc engines, the 50cc class is restricted by top speed, rather than the total engine size.


Just as an example, in the United States, most states require a 50cc scooter to have a maximum top speed of about 30 miles per hour or 48 km/h.


In many European countries, the top speed for the 50cc class is 45 km/h, and in Sweden, the top speed for the same class is either 45 km/h or 25 km/h, depending if the scooter belongs to Moped Class 1 or Class 2.


If you’d like to know more about the differences between Swedish Moped Class 1 and 2, please check out episode 6 of 30 Minute Motorcycling.


Either way, it might surprise you that a 50cc engine is capable of speed beyond the 45 km/h or 30 mph – a derestricted engine can actually reach speeds as high as 96 km/h or about 60 miles per hour.


So with that in mind, let’s get to how it’s actually done. First, though, I need to get a boring but nevertheless CRUCIAL disclaimer out of the way.


If you’re thinking about derestricting your 50cc scooter, you need to have a full motorcycle license. Not only that, but you must also have valid motorcycle insurance.


If you don’t have either of these things, and you get stopped by the police, prepare to be in a load of legal trouble.


OK, now, let’s talk about two common ways you can derestrict a 50cc scooter.


The first one is to remove the variator restrictor, which is often found behind the variator, which in turn, is part of the CVT transmission that most modern scooters have.


One example of a scooter that has this is the Genuine Roughhouse 50, and if you’d like to see how to remove the variator from one, I’ve included a link in the episode description to a tutorial from the New Scooters 4 Less YouTube channel that covers this in great detail. 


The second common method to derestrict a 50 cc scooter is to cut a specific cable leading to the CDI box and adjust a fuel washer inside the carburetor.


Did you know that your CDI box has a special connector that transmits information about your scooter’s RPMS?


And knowing that, what do you think would happen if you disconnected or cut this connector – which is usually purple, by the way?


That’s right – you’ll fool the scooter into thinking that it has a much lower RPM rating than it actually does.


Of course, that’s just half the battle – you’ll also need to adjust a small washer inside your carburetor that controls how much fuel goes into it.


Sounds complicated? Well, it can be, so if this feels too intimidating to you, I’d advise against this approach. Of course, if you think that you’re up for it, I’ve included a link in the episode description to another tutorial video on YouTube that shows you how to do this.


And that’s what it means to derestrict a 50cc scooter, why the 50cc engine class is restricted so much, and two methods to derestrict a scooter of this engine size. 


Once again, please remember what I said earlier about needing a full motorcycle license if you’re going to attempt this. 


Anyway, I hope you enjoyed listening and, above all, that you discovered something new in this episode.


Until next time, keep your helmet on, and your eyes on the road. Bye!