Jabiru 3300 - IRREGULAR; LOW COMPRESSIONS

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: 87 of 103
L:\files\Manuals_For_Products\Engine_Manuals\Engine Maintenance Manual 22 & 33\JEM0002-5.docx
Possible Cause
Remedy
15)
High oil pressure
At very low temperatures, a pressure reading of up to around 500 kpa
doesn't necessarily indicate a malfunction
16)
Starting speed too low
Preheat engine
Figure 48 – Choke Schematic
10.16 Irregular / Low Compressions
Symptoms
Possible Cause
Remedy
1)
Compression on 1 or more
cylinders low
Debris on valve seat
Blow debris off seat – Section
9.18.2 refers.
Incorrect valve clearance
adjustment (solid lifter engines
only)
Re-set valve clearance per
Section 9.16.
Leaking head / cylinder seal
Check head bolt tensions & re-
test. If leak remains head must
be removed and re-lapped to
the cylinder. Refer to the
Overhaul Manual for details.
Hydraulic lifters locked
Excess oil pressure can cause
lifters to hold valves partially
open. Adjust engine oil
pressure.
Jammed or defective hydraulic
lifter: replace.
Worn cylinder / piston / rings.
Overhaul engine.
Burnt or worn valve or seat
Replace Valve &/or head. Refer
to Engine Overhaul Manual.