Reducing top speed of (moped type) CVT gearbox ?

[CompoSimmonite]

I know to increase top speed of an automatic moped / scooter you remove a spacer between the variator pulley flanges.
On the other hand I want to restrict the top speed of a petrol quad so I can legally modify and register it as a mobility scooter ! This is a simple process (- max width, max weight, indicators, hazards, horn, lights & handbrake) other than achieving the max speed requirement of 8mph
My quad, a Yamaha YFA125, has a CVT gearbox (with reverse) will do nearly 50 mph so I'm wondering if, in theory, increasing the size of the variator spacer together with smaller diameter tyres would significantly reduce top speed to get the required 8mph ?
Cheers.

 

[hotponyshoes]

That would make sense to me.

But probably easier just to fit an electronic speed limiter?

 

[carbonarc]

 

[mr haynes]

Restricting throttle opening an option?

 

[jsf55]

Restricting throttle opening an option?

Blank off half the opening too the carb ?

 

[addjunkie]

Agri register it, then you dont need to reduce the speed!

 

[roofman]

fine ballance...you want the motor producing decent peak power as in RPM for inclines etc but not screaming its head off when going down high street pavements. Go too big on the variator and it will just bog down i should think. Should you be thinking of a restrictor plate in the inlet tract just like restricted bikes for under age full licence holders.