Author Topic: Douglas Dragonfly kickstart Mechanism  (Read 2841 times)

0 Members and 1 Guest are viewing this topic.

Offline Eddie Doc

  • Member
  • *
  • Join Date: Dec 2012
  • Posts: 15
  • Location: Cheshire, UK
Douglas Dragonfly kickstart Mechanism
« on: 01 Mar 2014 at 12:55 »
Can anybody shed light on the sett up for a Dragonfly kickstart mechanism, I've followed the book now on two occasions  and each time thinking I've got it sorted put the engine back into the frame and within half an hour of messing the thing jams up again.
Having taken the start quadrant out it looks as if the first tooth is ground almost flat (why I do not know ) I have a spare and this looks exactly the same.
At times when operating the kickstart it tends to jam and on close inspection the ground tooth jams on top of the tooth inside the gearbox.
Has anybody had this trouble before and been able to sort it out successfully.
I've never had this bike running as I bought it as a basket case, it came in boxes like a jigsaw so not too sure if some parts are good or bad.
The gearbox came as a complete lump and I thought it worked OK.
Engine number 1195/6 Gearbox 2095/6
1956 year.
Many thanks.  Ed.

Offline tck

  • Senior Member
  • ***
  • Join Date: Jul 2004
  • Posts: 342
    • old racer
Re: Douglas Dragonfly kickstart Mechanism
« Reply #1 on: 01 Mar 2014 at 13:42 »
I guess the first tooth is ground away to stop the dreaded tooth lock where the first tooth of the quadrant goes head to head with a tooth on the pinion if the pinion happens to be just in the right spot.
This is a common fault on many boxes notably the Vincent where a lock up on that kick would be your last! the first tooth on the quadrant it should be reduced  square and very polished so that it moves the pinon rather than comming head to head.
Assuming the first tooth is ground correctly (and two out of two suggests it is) perhaps there is play in the bearings of the quadrant allowing locking to occur

Offline eddie

  • Master Member
  • ****
  • Join Date: Mar 2006
  • Posts: 1654
  • Location: Hampshire, UK
Re: Douglas Dragonfly kickstart Mechanism
« Reply #2 on: 01 Mar 2014 at 15:17 »
Ed,
      The problem you have described is usually caused by the kickstart ratchet not being free to slide/rotate on it's bush. This assembly is mounted on the tail end of the layshaft, and the nut that secures it also keeps the layshaft in place, so needs to be reasonably tight but overtightening it can cause the sleeve for the kickstart ratchet to get squeezed and become barrel shaped. I prefer to assemble the tail end of the layshaft dry with Loctite on the thread, then don't overtighten the nut - rely on the Loctite to prevent it moving (by all means, retain the tab washer if you prefer, but the tab washer will still permit a small amount of movement whereas Loctite will hold the nut in place, even if the bush creeps round). Once the Loctite has cured, you can oil up as normal.
    If you have to have the gearbox out again, you can do it without disturbing the engine. Remove the gearbox sprocket assy, remove the toolbox, take out the swinging arm pivot bolt. The swinging arm can then be pushed back far enough to remove the gearbox, leaving the engine in place (You may need to release the engine mounting bolt to let the engine slide forward in the slot).

    Regards,
                  Eddie.

Offline Eddie Doc

  • Member
  • *
  • Join Date: Dec 2012
  • Posts: 15
  • Location: Cheshire, UK
Re: Douglas Dragonfly kickstart Mechanism
« Reply #3 on: 02 Mar 2014 at 10:42 »
Thanks for the quick responce and whats more each reply makes perfect sense, my gearbox was built and put together by persons unknown some years ago. Most things I've looked at seem to be in good order and put together well but little things can be very testing when settings or torques are not carried out correctly. The old manuals are also quite lacking in detail leaving a lot to the experience of the person building engines and gearboxes.
I had actually worked out the possibility of splitting the the box from the engine pulling it backward to remove.
Just the thought of doing this all again filled me with misery.
Oh the joys!!!!