It may be your stator, coil or even your spark plug give these a go if your stator isn't giving enough power it won't give the electrical charge to your coil
Try this it may be the problem
to answer your question my sons derbi senda r does 55mph with me on it and im 14stone but remember it is unrestricted and if you upgrade to a 70 or 80cc kit it will go even faster
there is a restrictor in the carb try tht
Should be just after the postive output from the battery, fuse is a 4amp and should be just a couplr of inches from the battery
Its 19 to 22 newton meters on a torque wrench. It should say in the manual under section 'torques'.
To derestrict a Derbi Senda 50, you typically need to remove or modify certain components that limit its performance. This often involves removing the exhaust restriction, adjusting or replacing the carburetor jets, and possibly altering the variator weights in the transmission. Additionally, checking and ensuring that any electronic restrictions are bypassed can help increase the bike's top speed. Always make sure to comply with local regulations regarding modifications and safety.
Derbi was created in 1922.
The motto of Derbi is 'Mucho + k Moto'.
Senda prohibida was created in 1957.
Mitsuo Senda was born in 1940.
Sadaaki Senda died in 1908.
Kakou Senda was born in 1924.
Kakou Senda died in 2000.