Compression Test - Partner K 650/700 Active Workshop Manual

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Cylinder and piston
Check that the outlet hole in the valve is
open, in similarity with the hole in the
cylinder wall.

Compression test

The engine will only achieve maximum power and perfect functioning if the mechanical
components such as cylinder, piston, circlips, and gaskets, are in satisfactory con-
dition.
A simple way of checking the condition of the engine is to measure the pressure in the
cylinder with a compression gauge when the engine is turned over with the starter.
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5. Read off the pressure on the gauge. Release the pressure by pressing in the valve
cone on the side of the gauge connection. Repeat this procedure twice and
calculate a mean value from the tests.
NOTE!
If the engine has been disassembled it should be "run in" first in order to achieve a
correct result.
Compression pressure
Average value for new engine: K650, 700 = ca 150 psi, K950 = app. 130 psi,
K1250 = app. 110 psi.
Engine renovation is recommended if the pressure is more than 30 psi below the values
specified above.
If a low pressure value is obtained, repeat the test procedure after pouring a teaspoon
of engine oil (SAE 30) in the cylinder through the plug hole. If the pressure increases
it is very likely that the piston, circlips and cylinder are severely worn and need
replacing.
Check that the outlet hole in the valve is
open, in similarity with the hole in the
cylinder wall.
Clean if necessary.
1. Run the engine warm for a few minutes.
2. Replace the plug with the compression gauge. Make sure
that it is tight between the cylinder and gauge.
3. Move the stop switch to the stop position.
4. Firmly pull the engine over 5–6 times.