MV Agusta BRUTALE 910 S, Workshop Manual

Page: 28 / 112

Measuring compression in the cylinder
The following tools are necessary in order to carry out
this procedure:
Spark plug key: n° 800089013
Compression measurer
Adapter for the compression measurer.
A) Heat the motor to the usual functioning tem
perature (of regime);
B) Switch off the engine, remove the tank, air box
and sparkplugs;
C) Measure cylinder compression.
Drag the motor into rotation by means of the starting
motor with the butterfly valve completely open until the
compression measurer indicator (compessionmeter)
no longer rises; the compression measurement
obtained is the maximum.
Be sure the battery is completely charged.
- Repeat the procedure for the other cylinders.
N.B.:
If the compression in the cylinder is lower than
the minimum value of the reported range, check the
following points:
A) carbon deposits on the walls of the combustion
chamber and on the piston ceiling;
B) lthe head gasket is not of the correct measure-
ments;
N.B.:
If the compression in the cylinder is lower than
the minimum value of the reported range, check the
following points:
A) The seat of one or more valves is damaged and
the valves do not maintain the compression pres-
sure;
B) One or more valves have null functioning play;
C) The piston, cylinder play is excessive;
D) The cylinder head is twisted and/or the head gas-
ket is damaged;
E) Excessive play between ring and cable.
- 12 -
Engine
B
NOTE
Before carrying out the compression trial,
accurately check the battery tension since
the compression value which appears is
quite influenced by the rotation velocity of
the motor, and consequently by the bat-
tery tension.
NOTE
Cylinder compression control (280 rpm-min.)
Motore Tipo Press. Min (bar) Press. Max (bar)
910 S 7,5 14