PRM NEWAGE PRM 125, Workshop Manual

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15
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PRM 125
8. FAULT FINDING
The following fault finding chart is designed to help diagnose some of the problems which might be encountered. It
assumes that the installation and operating instructions in this manual have been followed and we advise that these are
checked before proceeding to fault finding.
To avoid prejudicing warranty rights, no repair or other work should be done on the gearbox during the warranty without
first contacting PRM Newage Ltd. or an authorised distributor or dealer for advice.
FAULT FINDING CHART
SYMPTOM CAUSE REASON REMEDY
No drive ahead or astern Broken drive plate
Broken input shaft
Broken output shaft Replace drive plate
Replace input shaft
Replace output shaft
Propeller speed does not
increase with engine speed,
ahead and astern Remote control cable or
linkage not allowing F-N-R
lever to move correct
distance
Too much oil within gearbox Remove cable and operate lever
by hand to check movement.
Adjust cable if necessary
Recheck oil level and adjust.
Propeller speed does not
increase with engine speed
in one direction only Damaged clutch cones
Too much oil within gearbox
Incorrect lever setting Remove and examine clutch
and replace if necessary
Reset lever to end stops
Recheck oil level and adjust.
Excessive noise from
gearbox at low speeds Engine idle speed set too low
Torsional vibration Faulty adjustment
Torsional incompatibility of
elements in driveline Increase idling speed
If not cured by increasing engine
idling speed, refer to engine
supplier
Excessive noise throughout
operating range Defective input coupling
Propeller chaft misalignment Input coupling worn or
damaged
Hull flexing or faulty
installation Remove, examine and replace if
necessary
Check the alignment of the
propeller shaft coupling; if
necessary rectify by adjusting
the shims under the engine
mounts or the engine mounts
themselves
Excessive vibration
throughout operating range Propeller out of balance
Engine/gearbox
misalignment
Defective bearing Propeller damaged or badly
machined
Faulty installation
Bearing worn or damaged Remove the propeller and check
that the pitch, weight, diameter
and balance of all the blades are
equal and rectify if necessary
Remove the transmission and
check that the flywheel face is
flat and that the flexible input
coupling is aligned correctly
Isolate defective bearing,
remove and replace
Excessive oil temperature Power too high
Oil level too high/low Incorrect engine rating
Incorrect oil type Re-assess engine power
Fill with correct oil
Fill to correct oil level on dipstick
Oil level needs constant
topping up Oil leaks Defective oil seal, sealant or
‘O’ ring Clean the outside of the
gearcase, particularly around
the ends of shafts including the
output shaft. Run the engine
and inspect the gearbox for
leaks. Replace seals as required
Escape of high pressure from
gearbox when dipstick is
removed Defective breather causing
leaks past oil seals Contact distributor or factory for
advice
Difficulty in moving single
lever control Faulty installation Incorrect selector adjustment
Remote control operating
cable kinked or frayed Re check adjustment see 9.7.6
for procedure
Check the installation and
eliminate all tight bends in the
cable
Warning:
Before carrying out any service work always ensure that the engine is switched off and
disconnect the operating cable from the gearbox.
Caution:
The above operations should be carried out by suitably qualified personnel and strictly in
accordance with the procedures detailed in the workshop manual