PIAGGIO 2012 MSS APE 50, Service Station Manual

Page: 41 / 117

Probable cause and troubleshooting
DETONATIONS TO THE EXHAUST
Possible Cause Operation
Detonations in the silencer to the gas release Check the ducts and the membrane of the choke device on the
carburettor.
NOISE - KNOCKS
Possible Cause Operation
Worn or leaking shock absorbers Replace.
Flexible buffers of the swinging arms Replace.
Insufficient lubrication of the hubs Remove the hubs and fill the appropriate chamber with special
grease.
RUBBER JOINT FAILURE OF THE SECONDARY PIPE ON THE AIR SILENCER
Possible Cause Operation
Secondary air reed locking Replace.
Secondary air filter clogging Clean the filter and the box.
Clogging of the secondary air joint on the silencer Descale the joint taking care to not let the residues fall into the
silencer.
THE VEHICLE PULLS TO ONE SIDE
Possible Cause Operation
The pressure of one of the tyres is not right Check and set to the prescribed pressure
Rear swinging arms Straighten out if possible, or replace.
Worn rubber buffers Replace.
Engine
ENGINE STOP
Possible Cause Operation
Idle speed too low Work on the appropriate adjuster screw del of the carburettor.
Dirt or water in the mixture of the ducts Clean thoroughly.
Inefficient spark plug Clean and adjust the gap between the electrodes or replace.
Cock obstruction Clean.
H.V. cable or spark plug hood damaged Check or replace.
Fuel tank cap breather obstruction (defective fuel system) Clean properly.
CRANKSHAFT KNOCKS
Possible Cause Operation
Excessive clearance of the main bearings Replace.
Big end failure Replace the crankshaft.
Crankshaft unbalanced Check the alignment
Piston pin worn Replace.
RINGING OF THE PISTON
Possible Cause Operation
Excessive clearance between the piston and cylinder Replace the piston and correct the cylinder.
Excessive clearance of the roller pin-connecting rod small end
or piston pin
Review (for any replacement of the rollers of the connecting rod
small end, see the section "Specifications").
MSS APE 50
Troubleshooting
TROUBL - 41