Author Topic: Idle-system  (Read 2398 times)

Offline Marx3

  • Jet Head
  • ****
  • Posts: 306
Idle-system
« on: March 28, 2010, 08:58:55 AM »
Hi, I was wondering; how far up through the rpm does the idle-system have effect on the mixture

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5418
Re: Idle-system
« Reply #1 on: March 29, 2010, 02:29:26 AM »
It's more about throttle angle and engine vacuum than rpm.  The idle system is described in our book, and how each part of it works, etc......Cliff

Offline Toronado

  • Carb lover
  • ***
  • Posts: 113
Re: Idle-system
« Reply #2 on: April 02, 2010, 03:16:37 AM »
I heard idle sytem effects 0 through 60mph i do not
know if thats true, it sounded a little fast to me for the
idle system still effecting any thing much over 30mph.

Is there air and fuel still being feed from idle channels,
in tell a carb. reaches max rpm, mph, or vacuum (a ballpark number)?

Offline Cliff Ruggles

  • Administrator
  • Qjet Hero
  • *****
  • Posts: 5418
Re: Idle-system
« Reply #3 on: April 02, 2010, 03:39:00 AM »
As mentioned, it's about throttle angle, and engine vacuum created at the front edge of the throttle plates than will cause fuel to be pulled from the idle mixture screw holes and/or the tranfer slots.  This will not be the same for any two set-ups, but I would imagine most would be feeding some fuel to the engine thru the idle system at really low throttle angles and when the engine is pulling a lot of vacuum....Cliff