TOHATSU BFT250A Service Manual page 449

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CONNECTING ROD BEARING OIL
CLEARANCE
To check connecting rod bearing-to-crankpin oil
clearance, remove the connecting rod bearing caps,
crankshaft, and connecting rod bearings (page 15-7).
Clean each crankpin, connecting rod bearing cap, and
connecting rod bearing with a clean shop towel.
Check each crankpin and connecting rod bearing for
scoring, scratches or damage.
Install the connecting rod bearings, crankshaft, and
connecting rod bearing caps.
Tighten the cap bolts to the specified torque (page 15-
17).
Remove the bearing caps and place one strip of
plastigauge [1] across each crankpin.
• Set the plastigauge in the axial direction.
• Avoid the oil passage in the crankpin when setting
the plastigauge.
Reinstall the bearings and caps.
Tighten the bolts to the specified torque (page 15-17).
• Tighten the connecting rod bolt with care not to turn
the crankshaft and/or the connecting rod.
Remove the bearing caps and measure the pressured
width of the plastigauge using the scale [2] printed on
the plastigauge's bag.
STANDARD:
0.020 – 0.044 mm (0.0008 – 0.0017 in)
SERVICE LIMIT:
0.05 mm (0.002 in)
• Take the widest width on the plastigauge.
If the measurement exceeds the service limit, replace
the bearings by referring to connecting rod bearing
selection table (page 15-38) and measure the oil
clearance again.
If the measurement still exceeds the service limit,
replace the crankshaft with a new one and recheck.
CYLINDER BLOCK
[1]
[2]
15-35