SELVA MARINE Blue Whale 250 EFI, Service Manual

Page: 114 / 377

POWR
Power unit
5-1
6P23H11
Power unit
5
Checking the compression pressure
1. Start the engine, warm it up for 5 min-
utes, and then turn it off.
2. Remove the engine stop lanyard from the
engine stop lanyard switch.
3. Disconnect all fuel injector couplers.
4. Remove the ECM cover, all ignition coils
and spark plugs, and then install the spe-
cial service tools into a spark plug hole.
CAUTION:
Before removing the spark plugs, blow
compressed air in the spark plug well to
clear out any dirt or dust that may fall into
the cylinder.
5. Disconnect the throttle cable joint from
the accelerator lever, and then place and
hold the lever in the fully open position of
the throttle.
6. Crank the engine until the reading on the
compression gauge stabilizes, and then
check the compression pressure.
7. If the compression pressure is below
specification and the compression pres-
sure for each cylinder is unbalanced, add
a small amount of engine oil to the cylin-
der, and then check the compression
pressure again.
NOTE:
• If the compression pressure increases,
check the pistons and piston rings. Replace
if worn.
• If the compression pressure does not
increase, check the valve clearances,
valves, valve seats, cylinder head gaskets,
and cylinder heads. Adjust or replace if
necessary.
Checking the oil pressure
1. Place a rag under the oil pressure sen-
sor.
2. Remove the oil pressure sensor, and
then install an oil pressure gauge
1
into
the oil pressure sensor installation hole.
NOTE:
Use a general pressure gauge.
3. Start the engine and warm it up for 5 min-
utes.
Compression gauge
1
:
90890-03160
Compression gauge extension
2
:
90890-06563
S6P25010
1
2
S6P25015
Minimum compression pressure
(reference data):
740 kPa (7.4 kgf/cm
2
, 107.3 psi)
S6P25020
1