More/better speed with Vespa ET4 50

I need help....!!!

Does anyone know how I can get more speed out of my Vespa ET4 (50cc)? I can drive it up to 45km/h just fine, even uphill with 2 people on it, but as soon as I reach 45km/h it is as if it is "electronically" stopped from giving me a higher rpm...

Please please please - what can I do, what can I buy or what can I take away...


Thanks for all tipps & help / Johan

hi johan maybe your et4 50 is restricted meaning it has restrictions on going over 45kms, you can check your manual or your dealer about this. now if it has no restrictions maybe thats the fastest she can go so you need to set it up. if you do a lot of motorways and with backride then you must get a malossi kit or polini kit 70cc or if there is much higher cc that would be great, next you need to change your existing carb to a bigger one, 28mm or 30mm delorto or kehein flatslide, next you need a malossi reedcage, next get a malossi or polini variator and roller weights. check your existing roller weights and get back to me so ill know what roller weights you need to buy. hope this helps. cheers!

Hi there. It's a simple bit of tuning!! The Et4 50 is restricted by the cdi unit. To get more out of her, you need to make a cut in the cdi unit. You only have to cut till you sever a wire a few mms below the surface.   See the attached link:

You should now be able to get about 70km/h out of her. It might also pay to change the main jet to a 78 instead of the original 76 if you feel the need. As the Et4 uses a Keihin carb(Japan),you'll probably have to go to  a Honda/Suzuki/Yamaha or Kawasaki bikeshop rather than a Vespa shop. If you can't find a jet, call the Keihin importer in your country.