Engine Maintenance Manual
Jabiru Aircraft
Pty Ltd
JEM0002-5
Jabiru 2200 & 3300 Aircraft Engines
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ISSUE
1
2
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5
Dated : 2nd June 2015
Issued By: AS
Page: 62 of 103
L:\files\Manuals_For_Products\Engine_Manuals\Engine Maintenance Manual 22 & 33\JEM0002-5.docx
9.11
Carburettor Inspection & Adjustment
Required Tools:
Screwdrivers
Ruler or other measuring instrument
Parts and Material:
N/A
Type of Maintenance:
Heavy Maintenance
Level of Certification:
L2 or LAME (A&P or LSA Repairman / Maintenance)
Return to Service:
L2 or LAME (A&P or LSA Repairman / Maintenance)
Check carburettor joints for degradation.
Check carburettor linkage for full & free movement, correct positioning of stops and security.
Ensure that when the choke is selected fully ON and released the arm on the carburettor does
not move
– if the choke arm springs back slightly when the control in the cabin is released this
can result in difficulty starting the engine. When in the ON position the choke lever on the
carburettor must remain in the fully ON position regardless of weather there is a hand on the
control in the cabin.
The carburettor automatically adjusts the mixture to account for altitude
– there is no provision
for in-flight mixture adjustment as standard.
Ensure that the carburettor sense tube is connected from the carburettor to a fitting on the
filtered side of the hot air mixer box.
Idle stop screw is a 7mm screw against throttle lever. Adjust its position to adjust engine idle
speed. Note that the throttle idle stops inside the cabin may also need to be adjusted.
Standard idle mixture screw position is 1-1/4 turns out. Fine adjustment may be necessary to
give a smooth idle.
Remove the spring clip and detach the bowl from the carburettor. Measure the distance from
the fuel surface to the top of the bowl
– it should be approximately 12mm.
Inspect the bowl for dirt or contamination and clean if required. Inspect the visible jets of the
carburettor and clean if required.
Gently lift the floats of the carburettor with the bowl removed until the float needle touches its
seat. The floats should be approximately level when the needle touches the seat. If necessary
the float assembly can be removed by pressing out the pivot pin and the float height adjusted
by gently bending the arm which connects to the float needle.
Inspect the condition of the seal between carburettor and bowl.
Re-fit the bowl and snap the clip back in place.
CAUTION
Ensure clip is properly on: pressed up against the stopper cast into the bowl.
9.11.1 Tuning
The mixture is set by selecting jet sizes. As supplied, the engine has jets to suit a majority of
installations. However, the mixture may be affected by many variables and in some cases
adjustment will be necessary.
It is strongly recommended that for any new installation a thorough assessment of the engine’s
fuel/air mixture is carried out. This may be done by EGT sensors or Lambda type sensors.
CAUTION
Do not change carburettor settings without consulting with Jabiru Aircraft or our local
authorised representative. If EGT readings fall outside the range given above, contact
Jabiru Aircraft or our local authorised representative.
Spark plug colour can be used as a general indicator of the health of the engine and the
suitability of the fuel/air mixture:
a. Brown to Dark Brown
:- Plug & calibration is correct.
b. Velvet Black
:- Mixture too rich. Check choke. Insufficient air intake. Check for clogged air
filter.
