Author Topic: Carburetor Choke butterfly question ?  (Read 496 times)

Online McCabe-Thiele (Ted)

  • Grogu
  • *
  • Posts: 6386
    • View Profile
Carburetor Choke butterfly question ?
« on: August 27, 2020, 01:02:43 PM »
Just finished assembling the carburetors now that I have the new "O" rings via NJ.
I've done the initial set up with the throttle valve positions on my bench - the final balancing will I guess need to be done when the engine is running.

Just wondered with the choke adjustments what's best - all the butterflies horizontal when the choke is OFF or all the butterflies fully closed when the choke is fully ON. Seems I can't do both is this normal ?

Photo shows my situation.
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html
http://forums.sohc4.net/index.php/topic,151576.msg1731556.html#msg1731556

Online Laverda Dave

  • SOHC Jedi
  • Posts: 2619
  • Health is wealth
    • View Profile
Re: Carburetor Choke butterfly question ?
« Reply #1 on: August 27, 2020, 01:26:21 PM »
I adjusted mine to be all open at the maximum amount as you have in the second picture.
The choke is off 99% of the time and by adjusting them to all be closed at the same amount with the choke on for cold starting will result in them not being fully open when the choke is off thus affecting performance.
1976 Honda 400/4
1977 Rickman Honda CR750
1999 Honda VFR 800FX
1955 750 Dresda Triton
1978 Moto Morini 350 Sport
1978 Honda CB400/4 'Rat' bike
1982 Laverda 120 Jota

Online McCabe-Thiele (Ted)

  • Grogu
  • *
  • Posts: 6386
    • View Profile
Re: Carburetor Choke butterfly question ?
« Reply #2 on: August 27, 2020, 04:47:34 PM »
I adjusted mine to be all open at the maximum amount as you have in the second picture.
The choke is off 99% of the time and by adjusting them to all be closed at the same amount with the choke on for cold starting will result in them not being fully open when the choke is off thus affecting performance.

That makes sense thanks. Ted
Honda CB500 K1 (new pit dug out ready)
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html
http://forums.sohc4.net/index.php/topic,151576.msg1731556.html#msg1731556

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal