TOHATSU BFT115A Service Manual page 489

CRANKSHAFT MAIN BEARING OIL
CLEARANCE
To check main bearing-to-journal oil clearance, remove
the lower block, crankshaft, and main bearings (page
15-15).
Clean each main journal and main bearings and check
for wear or damage.
Install the main bearings, crankshaft and lower block to
the cylinder block, and tighten the bolts to the specified
torque (page 15-24).
Remove the lower block and main bearings and place
one strip of plastigauge (1) across each main journal.
• Set the plastigauge in the axial direction.
• Avoid the oil passage in the bearing journal to set
the plastigauge.
Reinstall the main bearings, crankshaft and lower block
to the cylinder block, and tighten the bolts to the
specified torque (page 15-24).
• Do not turn the crankshaft during this check.
Remove the lower block and main bearings and
measure the pressured width (2) of the plastigauge
using the scale (3) printed on the plastigauge's bag.
STANDARD:
No.1, 2, 4, 5: 0.017 – 0.041 mm
(0.0007 – 0.0016 in)
No.3: 0.025 – 0.049 mm
(0.0010 – 0.0019 in)
SERVICE LIMIT:
No.1, 2, 4, 5: 0.05 mm (0.0020 in)
No.3: 0.055 mm (0.0022 in)
• Take the largest width on the plastigauge.
If the measurement exceeds the service limit, replace
the bearings by referring to crankshaft main bearing
selection table (page 15-45) and measure the oil
clearance again.
If the measurement still exceeds the service limit,
replace the crankshaft with a new one (page 15-15) and
recheck.
CYLINDER BLOCK
(1)
(2)
(3)
15-41