Jabiru 3300, Instruction And Maintenance Manual

Page: 27 / 103

Page No: 27 Issue No: 1 Date: 031100 Issued By: PJA
If readings are below 6 bar (90 psi) a check of the pistons, cylinders, valves & cylinder
heads must be undertaken.
Alternatives:
* Pressure loss or leakage tester eg SUN or BOSCH tester; max. allowable pressure loss
is 25%.
* Checking by commonly used pressure difference method; place orifice of 1 mm ID and
3mm length between the two pressure gauges. This will give the same result as with the
above instrument. Max. pressure drop is 25%.
6.5 Spark Plugs
Do not use steel or brass brushes for cleaning & never sandblast plugs.
Clean with plastic brush in a solvent.
Check electrode gap & if necessary, adjust to 0.55 - 0.6mm (0.022" - 0.024") by carefully
bending the electrode. Recommended Plugs: NGK D9EA
IMPORTANT
Only tighten spark plugs on cold engine & only to the torque values shown in para. 9.0
using appropriate anti-seize compound
Note: When plugs are removed from a warm engine, the following are indicators:
Light Coloured to Brown :- Plug & calibration is correct.
Velvet Black :- Mixture too rich. Check choke. Insufficient air intake. Check for
clogged air filter.
Oily, Glossy Coating :- Misfiring. Too much oil in combustion chamber. Worn
cylinder & piston rings.
Whitish with Melt Droplets :- Mixture too lean. Leaking valves.
6.6 Exhaust System
Visual check for damage, leaks & general condition.
6.7 Bolts and Nuts
Check for tightness, re-torque if necessary (see para. 9.0).