Diamond DA20-C1, Maintenance Manual

Page: 293 / 452

Page 3
Rev 21
76-00-00
Engine Controls
DA20-C1 AMM
DA201-C1
14 Jan 13
B. Mixture Control
The mixture control sets the fuel mixture between RICH and LEAN. It also stops the fuel supply to
the engine when set to CUTOFF. The mixture lever attaches to the control quadrant in the center
console. The mixture lever is the right hand lever in the control quadrant.
The mixture control lever has a lock-out lever attached. The lock-out lever prevents accidental
movement of the mixture control lever. The spring loaded lock-out lever engages in a toothed rack.
The toothed rack attaches to the tubular spacers at the right of the control quadrant.
A bowden cable connects between the mixture lever in the cockpit and the mixture control-lever at
the engine. The bowden-cable wire-end attaches to the mixture lever through a hole in a swivel
fitting. A screw locks it in position. A bracket holds the inboard end of the swivel fitting. Two rivets
attach the bracket to the mixture lever. The outer sheath of the bowden cable has a threaded end
fitting. Two nuts attach the end fitting to a tab on the side of the control quadrant.
The bowden cable goes from the center console up, behind the instrument panel and through the
firewall to the engine bay. A feed-thru fitting holds the cable in position at the firewall. A fire
resistant compound seals the bowden cable where it goes through the firewall. From the firewall
the bowden cable goes through a rubber grommet in the aft baffle on the left hand side.
On aircraft equipped with a standard fuel pump, the outer sheath of the mixture control bowden
cable has a threaded end that attaches to a bracket at the apron with two nuts, which can be used
to adjust the range of movement of the mixture control lever. The bowden-cable wire-end attaches
to the fuel-mixture control-lever of the fuel pump through a hole in the attachment bolt. You can
adjust the length of the wire at this point to set the correct fuel mixture control position.
On aircraft equipped with an altitude compensating fuel pump, the mixture cable has a notched
swivel termination at the engine end. The notch slides onto the mixture support bracket, which is
fastened to the apron. A keeper is bolted to the bracket to secure the bowden cable. There is a
rod-end attached to the end of the bowden cable that connects the mixture control cable to the fuel
mixture lever by a bolt.
C. Alternate Air
The alternate air control opens a by-pass for the engine air filter if it becomes blocked with debris
or ice. The alternate air lever attaches to the control quadrant in the center console. The alternate
air lever is the left hand lever in the control quadrant.
A bowden cable connects between the alternate air lever in the cockpit and the lever at the air-box.
The bowden-cable wire-end attaches to the alternate air lever through a hole in a swivel fitting. A
screw locks it in position. A small bracket holds the inboard end of the swivel fitting. Two rivets
attach the bracket to the alternate air lever.
The outer sheath of the bowden cable has a threaded end fitting. The end fitting attaches to a tab
bent from the side of the quadrant.
The bowden cable goes from the center console, up behind the instrument panel and through the
firewall to the engine bay. A feed-thru fitting holds the cable in position at the firewall. A fire
resistant compound seals the bowden cable where it goes through the firewall.