Author Topic: 930 concentric  (Read 287 times)

Offline Topdad

  • bob hebdon
  • Wise & Enlightened
  • *
  • Join Date: May 2011
  • Posts: 2650
  • Karma: 36
  • l
930 concentric
« on: 28.08. 2024 15:51 »
Been trying to get my A10 back from her slumber but after having what I thought was a good clean up  she still isn't running .Mag as now been cleaned and pickups back and plugs sparking well .so carb ?? can you remove the idle jet ?  thanks for your time bob
" rules are made for the guidance of wise men and the blind obediance of fools"
United Kingdom

Offline muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 11032
  • Karma: 132
  • Lithgow NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: 930 concentric
« Reply #1 on: 28.08. 2024 20:02 »
G'day Bob.
Some yes some no. The 930 Mk1 has a removable pilot jet screwed in to the body above the float. The Mk1.5 has a pressed in jet in the passage at the end of the air screw hole. It's only 0.016" and blocks easily.
Good luck.
Cheers The Premier 930 has a removable screw in pilot jet on the opposite side to the air screw.
Watch this video https://tinyurl.com/mtapz6ch which is the Mk1.5
I have found the easiest way is to put the carb through an ultrasonic cleaner. I have one myself but at the shop we charge $25 to do it.
Or remove the air screw and blast carb clean down that hole and the hole in the mouth of the carb followed by compressed air.
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
Australia
Muskys Plunger A7

Online Triton Thrasher

  • Scotland
  • Wise & Enlightened
  • *
  • Join Date: Feb 2009
  • Posts: 1990
  • Karma: 23
Re: 930 concentric
« Reply #2 on: 28.08. 2024 22:08 »
If we disregard two-strokes, only very early Mk 1 Concentrics had a pilot jet screwed up into the body.


Offline Rex

  • Wise & Enlightened
  • *
  • Join Date: Apr 2017
  • Posts: 1701
  • Karma: 8
Re: 930 concentric
« Reply #3 on: 29.08. 2024 08:36 »
True, most are running with the actual brass jet removed leaving just the tapped hole.
Many years ago on a T120 I assumed my bike had been the victim of a forgetful bodger, so I bought and fitted two new brass jets.
It made absolutely no difference to the running or starting.

Online JulianS

  • 1962 A10
  • Wise & Enlightened
  • *
  • Join Date: Mar 2017
  • Posts: 1451
  • Karma: 29
Re: 930 concentric
« Reply #4 on: 29.08. 2024 10:29 »
Most mark 1 concentrics had a pressed in pilot jet, not a screw in one. You do not need both.

See this article on the Amal/Burlen website on rebuilding the concentric and see under "pilot circuit" for cleaning the pressed in jet.

https://amalcarb.co.uk/technical/rebuilding-mark-1-concentric-carburetter

Offline Topdad

  • bob hebdon
  • Wise & Enlightened
  • *
  • Join Date: May 2011
  • Posts: 2650
  • Karma: 36
  • l
Re: 930 concentric
« Reply #5 on: 29.08. 2024 11:26 »
Thanks everyone for there input now have restored what I knew 4 yrs ago but which had gone completely from my memory cheers Bob
" rules are made for the guidance of wise men and the blind obediance of fools"
United Kingdom