Troubleshooting - Desert Aircraft DA85 Owner's Manual

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Trouble Shooting
Motor won't start:
Possibly flooded: The DA85 normally only needs to be choked for the first start of the day. Over
choking can cause flooding.
Check battery voltage (should be at least 5.0+ volts) and all ignition connections, wiring, and
switches. Check for breaks near all connectors, crimp joints or solder joints.
Voltage regulators can fail intermittently or totally. If using a voltage regulator, try testing with a 4 or
5 cell pack without the regulator.
Check tank venting, clunk position, and fuel flow.
Check all fuel lines for kinks, pin holes, or damage.
Does fuel move toward the carburetor when the prop is flipped?
If fuel isn't moving towards the carburetor, is the choke plate completely closing? Is the carburetor
or carburetor mount loose causing an air leak? Look for fuel seepage around the carburetor
mounting area.
Is the throttle set at idle or slightly higher after engine "pops" and choke is opened?
Make sure prop is flipped over with authority. The ignition won't fire at low speed.
If a lot of fuel drips from the carburetor, the engine may be flooded. If so, remove and dry spark
plug, or replace it. Try starting again without using the choke.
Motor runs poorly or stops:
Rough running can be an indication that the engine might be too rich. Make sure both
needles are adjusted to peak performance. Due to changes in air pressure and air flow in
the cowl when the plane is flying, the needles may need to be adjusted to deal with in flight
performance, not just the way the engine runs on the ground. This may take several ground
adjustments and flight tests.
Make sure carburetor has not come loose causing an air leak in the carburetor mounting
area. Look for fuel seepage.
If your radio has a Battery Failsafe option, the throttle can stop working momentarily when
the receiver battery voltage drops.
Check that the fuel clunk is intact and can move freely to the correct tank position.
Check all ignition connections and switches carefully. Faulty switches and contacts can
cause momentary loss of ignition power due to vibration and harness movement during flight.
Check Ignition battery voltage.
If the engine runs poorly and the RPM tops out at 3,000 to 4,000 RPM, make sure that the
polarity of the wires entering the connectors is correct (Brown to brown, orange to orange).
The connectors can be forced together the wrong way.
Make sure your fuel is fresh. Changes in atmospheric conditions can cause water
condensation in gas cans and tanks. Look for water in your fuel can and plane's fuel tank.
Needle settings may need adjustment when the engine is moved from one plane to another
or cowl configurations are changed. This is because even slight changes in air flow can
change the tuning of the carburetor.
Make sure the choke stays open during flight. Vibration and a heavy unsecured choke
linkage can cause the choke to close under high G-loads.
7

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