Automatic Project

Electric Start


The main difference between the non-electric start PK Automatica motor and the electric start one is the starter motor and a special flywheel that has gear teeth around the outside. The casing from the non electric start motor can be modified pretty easily to fit the starter motor.

The casing starts out the same when it is initially cast. On motors designated to be kick start only, Piaggio doesn't bother machining the starter motor hole or the threaded stud holes on either side that hold it in place.

All you need is a drill press and a hole saw to make the hole. The casing in this shot was stripped of all bearings so that none of the aluminum bits could get in and ruin things. I found the center of the area (just about), and bored the whole through the casing. It is important to make sure there is a lip (or shoulder) to the hole so that the starter motor has something to stop it pushing straight through the hole.

The next step is to drill out some holes for the studs which will hold the motor in place.

The factory motor comes with studs that are screwed in to the casing. I found it hard to find the rights studs so I just drilled straight through the casing and I will use bolts instead.

I also found that when I tried to test fit the starter motor the inside diameter of the hole and the outside diameter of the motor didn't fit. I had to remove about 1mm all the way around the perimieter of the hole. Once I was done, the bolt set up and hole look almost like a stock motor.

The motor is bolted in place with 2 nylock nuts so they won't shake free.

The final part of the puzzle is to relace the existing flywheel that came with the motor with one I found on eBay Germany that is specific to the automatica motor. The PK80 Automatica and 125 Automatica share the same flywheel but the 50cc version is very different and won't work with the drive pulley.

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