Engine Maintenance Manual
Jabiru Aircraft
Pty Ltd
JEM0002-5
Jabiru 2200 & 3300 Aircraft Engines
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ISSUE
1
2
3
4
5
Dated : 2nd June 2015
Issued By: AS
Page: 69 of 103
L:\files\Manuals_For_Products\Engine_Manuals\Engine Maintenance Manual 22 & 33\JEM0002-5.docx
Figure 41
– Valve Clearance Adjustment (Solid Lifter)
CAUTION
Continued operation with incorrectly adjusted tappets will result in damage to valves, valve
seats, valve guides & overhead gear.
Correct setting of valve clearance is critical to the safe operation of the engine & must be
carried out carefully, following the procedures given herein exactly.
9.18
Compression Check
Required Tools:
Tools as required in sections 9.15 and 9.16
Compression Tester
Leak-down Tester
Soft hammer
Screwdrivers
Parts and Material:
Soapy water
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)
Always carry out a cylinder head bolt tension check (Section 9.15) and, where applicable, valve
clearance checks (Section 9.16) before testing compression.
9.18.1 Compression Gauge:
Measure compression using a compression tester. Readings are taken with fully open throttle
valve at engine oil temperature between 30
°
& 70
°
C (90
°
to 160
°
F).
If readings are below 6 bar (90 psi) a check of the pistons, cylinders, valves & cylinder heads
must be undertaken.
CAUTION
Ensure ignitions are OFF and all personnel & equipment are well clear of propeller.
9.18.2 Pressure Differential Test:
As an alternative to a compression test, a pressure differential test (Leak down) can be carried
out. This is a much better test of the condition of rings, bore, head sealing and valve. This is
the normal test used in aviation and is strongly recommended by Jabiru Aircraft. It requires
specific test equipment.
The test is carried out with the engine in warm to hot condition.
Remove 1 spark plug from the cylinder to be tested and fit the leak-down tester in its place.
Pressure input is set to 80 PSI; a second gauge reads the differential. This is done with piston
on TDC on the firing stroke. A SUN or BOSCH tester pressure loss or leakage tester is used.
