Maintenance Data - TOHATSU MFS 25D Service Manual

Service Data

6. Maintenance Data

Description
Engine
Valve (IN/EX)
Valve Spring
Rocker Arm
Piston
Piston Pin
Piston Ring
Cylinder Head
2-16
Item
Compression pressure (reference value)
Note) After warming up, remove all the spark
plugs and injector connectors, then
take measurements with the throttle
fully opened.
Valve Clearance
Valve Stem Outer Diameter
Valve Stem Runout
Valve Guide Inner Diameter
Clearance Between Valve Stem and Guide
Valve Seat Contact Width
Free Spring Length
Rocker Arm Inner Diameter
Rocker Arm Shaft Outer Diameter (Arm Sliding Part)
Clearance Between Rocker Arm and Shaft
Maximum outer diameter
Outer diameter at 10 mm (0.3937 in) above
the lower end of the piston skirt
At right angle to the piston pin
Clearance Between Piston Diameter and
Cylinder Inner Diameter
Adhesion of Carbon on Piston Crown and
Ring Groove
Clearance Between Piston Ring and Ring
Groove
Piston Pin Hole Inner Diameter
Pin Outer Diameter
Clearance Between Piston Pin and Pin Hole
Ring End Gap
Note) Measure the Ring End Gap at the
bottom of the cylinder bore where there
is little wear if you do not have a ring
gauge.
Cam Bearing Inner Diameter
Distortion or Damage on Mating Surface
Carbon Adhesion in Combustion Chamber
Cooling Water Passage Clogged
Standard Value
With Decompression: 0.50 MPa
Without Decompression: 1.40 MPa
IN: 0.10 - 0.15 mm (0.0040 - 0.0060 in)
EX: 0.20 - 0.24 mm (0.0080 - 0.0094 in)
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IN: 0.008 - 0.040 mm (0.0003 - 0.0016 in)
EX: 0.025 - 0.057 mm (0.001 - 0.0022 in)
IN: 1.0 mm (0.04 in)
EX: 1.0 mm (0.04 in)
IN: 32.85 mm (1.2933 in)
EX: 32.85 mm (1.2933 in)
0.006 - 0.035 mm (0.0002 - 0.0014 in)
0.020 - 0.055 mm (0.0008 - 0.0022 in)
-
Top Ring: 0.03 - 0.08 mm (0.0012 - 0.0031 in)
Second Ring: 0.02 - 0.06 mm (0.0008 - 0.0024 in)
Oil Ring: 0.03 - 0.13 mm (0.0012 - 0.0051 in)
0.002 - 0.012 mm (0.0001 - 0.0005 in)
Top Ring: 0.13 - 0.25 mm (0.0051 - 0.0098 in)
Second Ring: 0.35 - 0.50 mm (0.0138 - 0.0197 in)
Oil Ring: 0.20 - 0.70 mm (0.0079 - 0.0276 in)
#3 - oil pump: 33.500 - 33.550 mm (1.3189 - 1.3209 in)
Distortion: 0.05 mm (0.002 in) or less
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4st 25/30 2022