The Choke

Is it just me or is it difficult to remove the slack from the choke operating cable?  When I received the engine unit back from Scooter Surgery it had a choke cable attached.  I had previously bought a choke operating button that fits on the nearside of the frame under the front seat.  I assumed that it was a simple matter of connecting this to the cable.  Not so for me it appears.

The choke barrel in the carburetor is held closed by a spring and when the choke button is pulled this lifts the barrel and opens the choke.  The choke is held open by rotating the choke button 90 degrees so that it aligns with detentes in its mounting.  

I would have thought fitting the cable would have been simple.  Well it was really but once installed I discovered that when the choke barrel was fully closed there was slack in the operating cable and the choke knob had to lifted a long way before the barrel started to move.

This shows how far the choke button could be lifted before it started to lift the choke barrel.  Well above the detent in the mounting, obviously no way of keeping the choke open.



 
 It seemed to me that the inner cable needed to be reduced in length by some 20mm.

  I tried to unsolder the nipples on the ends of the cable but had no luck, they must have been swagged and soldered.  The only solution was to cut off one end and make a replacement, I went for the choke knob end.

The only bit of brass I could find was a screw which enable me to have just enough material to make the replacement nipple.  This was soldered to the end of the cable and the surplus material cut off.

 

The new nipple in position

Flushed with my success I reassembled the choke operating cable only to find that I couldn't lift the choke knob high enough to engage with the detent.  Now the inner cable was too short!  

(NOTE:  when fitting the carburetor end of the assembly take GREAT care not to cross thread the cable end mounting in the carburetor body.  It's difficult to align because the  choke cable wants to fight the alignment and the body is very soft material.)

How could I have got it so wrong? What to do now?

Reduce the length of the outer to increase the length of the inner protruding beyond the end of the outer.  Having done this on a previous occasion I knew to be careful not to damage the inner cable when cutting through the outer. I reassembled everything with the new length cable only to find the slack back again, as I should have expected if I had thought about it.  At this point I gave up.  I will need to consult the experts to find out what I have been doing wrong, apart from cutting the cable. (When I find out how to make the choke work I will add it to this section).   I will also have to add a new choke cable to my next order.