Puch ZA50 Pull Starter (Part 2)

In Part 1, I showed how to modify the pull start to make it rotate in the counter-clockwise direction for use on the ZA50's flywheel.  In Part 2, I will show how to modify and mount the prawl onto the flywheel and mount the pull starter to the bike.

1)  First off, modify the prawl.  Since the prawl will rotate in the opposite direction,  you will need to modify the fins for the "catch bars" of the starter to engage one one side and the opposite side to help the bars retract down.  Basically you want to flip the current fin design as best as you can.  See marked areas where I ground down.

Stock prawl

2)  Now mounting the prawl onto the magneto.  You can do this a number of ways.  I asked Christophe at Tomahawk Tuning how he mounted it and he said he welded it on to the flywheel.  I have a Powerdynamo CDI setup on my ZA50 so I wanted a less permanent way to mount it.  After a lot of thought, I decided to tap and screw it onto the flywheel.


I removed the center nut that the prawl came with and enlarged the hole to make sure the crank end clears.  I drilled and tapped my magneto with M4 allen wrench screws.  Be sure to center the prawl into postion as best as you can to prevent rotational vibration on the crank.  As you can see, mines isn't absolutely centered but seem to not cause any significant vibration.  Also, all the extra holes on the prawl is due to my f-ups centering the prawl.  I probably redo this with a new prawl at a later time.  Remember to Locktite the screws down cause the flywheel will get hot.

3)  I decided to use an existing metal type magneto cover to mount the starter onto the motor.  I cut (more like drill cut) the center hole as shown below.  Cleaned it up and shaped it like so:

I used a rubber mallet and pounded the curve down from the top so the starter would have a flat mating surface to bolt on.  This also brought the prawl and starter into perfect tolerance with each other to my surprise.

Flattened

4)  Mate the starter to the magneto cover.  I used M5 flat head screws and nuts to mount it.  You can use washers to shim the starter if its not in the right tolorence with the prawl as needed.  In my case, it was perfect.  Be sure to pay attention to the orientation of the pull cord.  Your carburetor might be in the way of your pull.  Orient accordingly.

5)  Mount the starter assembly on the motor.  Mount the magneto cover as you would a stock one.  Here are the results:

Here is the video on how it performs:

Happy Tuning!!...

** UPDATE (04/02/14):  FAILURE!!  I think the hot glue got loose and caused the catch arm to get caught on the catch prawl in the wrong direction.

LESSONS LEARN:  USE EPOXY INSTEAD OF HOT GLUE. (See part 1) **

Back to the drawing board.