Compression Test Data - Perkins 100 Series Workshop Manual

1

Compression test data

Tests have shown that many factors affect compression pressures. Battery, starter motor condition, ambient
conditions and the type of gauge used can give a wide variation of results for a given engine.
Engine model
102-05, 103-07, 103-10, 103-13
103-15, 104-19, 104-22
A compression test should only be used to compare between cylinders of an engine. If one or more cylinders
vary by more than 350 KPa (50 lbf/in²) then those cylinders may be faulty.
A compression test should not be the only method used to show the condition of an engine, but it should be
used together with other symptoms and tests.
How to do a compression test
Note: Before the compression test, ensure that the battery is in good condition and that it is fully charged. Also
ensure that the starter motor is in good condition.
1 To ensure that the engine cannot start, disconnect the engine stop solenoid or ensure the engine stop
control is in the 'stop' position.
2 Ensure that the valve tip clearances are set correctly.
3 Remove the atomisers.
4 Fit a suitable gauge into the atomiser hole of the cylinder to be tested.
5 Operate the starter motor and record the pressure indicated on the gauge.
6 Repeat for each cylinder.
12
This document has been printed from SPI². Not for Resale
Pressure kPa (lbf/in²)
Standard
>2940 (426.6) @ 200 rev/min
>2940 (426.6) @ 250 rev/min
Workshop Manual, TPD 1377E, issue 4
100 Series
To be repaired
<2450 (355.5)
<2450 (355.5)