Thread: CIS fuel head
View Single Post
Alan L Alan L is offline
Registered User
Alan L's Avatar
Join Date: Apr 2006
Location: New Zealand
Posts: 3,249
Yes Nathan, that is correct. The system pressure works against the WUR pressure - which sits on top of the piston. When the air plate drops, it pushes the piston up - because the pin of the piston rests on the other end of the air plate arm. To lift the piston, the arm has to work against the WUR pressure. The lower the WUR pressure - the easier to lift the piston, which opens the metering slots = more fuel for a given amount of air. When you tune your idle CO you are just adjusting the height the pin sits at in the metering slots for a given opening of the air plate.
Now that I have it tuned approximately right, I can fiddle with the WUR. But from memory , in my 3 km run previously a month or so ago, I dont recall a hesitation.
Old 12-05-2007, 03:26 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #49 (permalink)