Maintenance Data - TOHATSU MFS25 Service Manual

Service Data

6.Maintenance Data

Part Name
Cylinder Head
Cylinder
Piston
Piston Pin
Piston Rings
Connecting Rod
Crankshaft
2-10
Item
Build up of carbon in combustion chamber
Distortion or damage on mating surface
Corrosion on the mating surface
Cooling water passage clogged
Deposition in water jacket
Wear of bore : Use cylinder gauge to
measure inner diameter.
Seizure, cylinder liner damage, or wear
Taper
Out-of-roundness
Distortion or damage on cylinder
head mating surface
Engine Anode
Outer Diameter
Measure outer diameter at 9mm (0.35in)
above lower end of piston skirt
(at right angle to piston pin).
• Piston Clearance
Carbon build up on piston crown
and in ring grooves
Scratch on the sliding surface
Measure side clearance between
piston ring and ring groove.
Measure piston pin hole diameter.
Clearance between piston pin and pin hole
Outer Diameter
Note : Measurement of ring
Ring End
end gap : If ring gauge
Gap
is not available, use
Top Ring
cylinder bore top or
Second Ring
bottom with small wear.
Oil Ring
Small End Inner Diameter
Big End Oil Clearance
Big End Side Clearance
Crankshaft runout : Use V blocks to support
crankshaft at journals of both ends.
Crank pin outer diameter
Main journal outer diameter
Metal bearing oil clearance
Crankshaft side clearance
Standard Value
61.00mm (2.4016in)
60.96mm (2.4000in)
0.020 to 0.055mm (0.00079 to 0.00217in)
Top Ring : 0.04 to 0.08mm (0.0016 to 0.0031in)
Second Ring : 0.03 to 0.07mm (0.0012 to 0.0028in)
Oil Ring : 0.05 to 0.15mm (0.0020 to 0.0059in)
0.002 to 0.012mm (0.00008 to 0.00047in)
16.00mm (0.6299in)
Ring Gauge 61.000mm (2.40157in)
Top Ring : 0.15 to 0.30mm (0.0059 to 0.0118in)
Second Ring : 0.35 to 0.50mm (0.0138 to 0.0197in)
Oil Ring : 0.20 to 0.70mm (0.0079 to 0.0276in)
16.01mm (0.6303in)
0.010 to 0.036mm (0.00039 to 0.00142in)
0.10 to 0.25mm (0.0039 to 0.0098in)
Less than 0.05mm (0.0020in) at
both ends and at the center.
29.98mm (1.1803in)
35.99mm (1.4169in)
0.012 to 0.044mm (0.00047 to 0.00173in)
0.05 to 0.15mm (0.0020 to 0.0059in)
25/30 2006