TOHATSU BFT75A Service Manual page 396

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VTEC ROCKER ARM INSPECTION
(BF90D/BF100A only)
Disassemble the rocker arm assembly parts:
– Primary rocker arm [1]
– Rocker arm piston [2]
– Piston stopper [3]
– Return spring [4]
– Retainer [5]
– Secondary rocker arm [6]
• Remove the pistons from the primary rocker arm by
applying low air pressure to the rocker arm. Take
care not to apply excessive air pressure as the
pistons can jump out of the rocker arm.
Check that the rocker arm pistons move smoothly.
If the pistons do not move smoothly, replace the rocker
arms as an assembly.
Apply the engine oil to the rocker arm piston and piston
stopper on assembly.
CAM HEIGHT
Clean the camshaft and check the cam surface for wear
and damage.
Clean the cylinder head bearing surfaces and check the
bearing surfaces for wear and damage.
Measure the cam height.
BF75D/BF80A
STANDARD:
IN: 34.070 – 34.375 mm (1.3413 – 1.3533 in)
EX: 35.223 – 35.508 mm (1.3867 – 1.3979 in)
SERVICE LIMIT:
IN: 33.870 mm (1.3335 in)
EX: 35.023 mm (1.3789 in)
BF90D/BF100A
STANDARD:
IN/PRI: 35.422 – 35.707 mm (1.3946 – 1.4058 in)
IN/SEC: 34.710 – 34.995 mm (1.3665 – 1.3778 in)
EX:
SERVICE LIMIT:
IN/PRI: 35.222 mm (1.3867 in)
IN/SEC: 34.510 mm (1.3587 in)
EX:
If the measurement is less than the service limit,
replace the camshaft with a new one.
CAMSHAFT JOURNAL O.D.
Clean the camshaft and check the journals for wear or
damage.
Measure the O.D. of each camshaft journal.
STANDARD:
41.935 – 41.950 mm (1.6510 – 1.6516 in)
35.223 – 35.508 mm (1.3867 – 1.3979 in)
35.023 mm (1.3789 in)
CYLINDER HEAD
[1]
[2]
[3]
BF75D/BF80A:
CAM CHAIN
SIDE
IN: (PRIMARY)
BF90D/100A:
CAM CHAIN
SIDE
[4]
[5]
[6]
IN
EX
IN: (SECONDARY)
EX
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