Replace your CDI
It is not recommended by the manufacturer to remove the speed limiter on a Fiat Doblo. The speed limiter is installed for the safety of the vehicle operator.
on 5occ - 150cc gy6 qmb or qmj engines the rev limiter is part of the cdi programming.
It is controlled by the ECU, which you cannot remove.
DO you know what the top speed of this car is?
I heard some people remove a fuse which will kill many things including the speed limiter but that isn't really safe. The better solution is to get a unichip which would in the same time add some horsepower as well as removing the speed limiter
You have to reprogramme the motor's ECU.
buy a SLD speed limit defender.. wire in job....
There is no governor on a any 80's vehicle
they are limited to 130 or 135 but sofware exists to remove the limiter, depends on which engine is in it, an R or T5 can do 150 with the limiter removed
Get the wiring diagram for your bike. I downloaded a great tank gy6 service manual that matched both my 50cc 4-stroke tank and baja scooters. I found CDI modules had a yellow and green wire going to something called speed selectable unit... I assumed a rev limiter. I diconneted the wires to it first. The bike didnt run.Then I tried connecting the green and yellow wires together, bypassing the rev limiter, and it worked great, so i did it to both bikes.
Buy a superchip programer.
take the screw out of the side of the engine it is a medium size screw in the side