Maintenance Data - TOHATSU MFS 4D Service Manual

Service Data

5. Maintenance Data

Part Name
Carbon deposition on combustion chamber wall
Deformation of mating surface and flaws
Cylinder Head
Corrosion of mating surface
Plugging of cooling water passages
Deposition on water jacket interior walls
Wear of bore : Measure bore by using cylinder gauge
Seizure, cylinder liner damage, or wear
Cylinder Taper
Out-of roundness
Deformation and damage of cylinder head mating faces
Outer diameter
Carbon deposition on piston crown and in ring grooves
Piston Flaws on sliding surface
Measure side clearance between piston 0.0031 in)ring
and ring groove.
Measure piston pin bore.
Piston pin clearance
Piston pin Outer diameter
Ring end gap
Piston rings
Small end bore
Connecting rod Big end oil clearance
Big end side clearance
Crank pin outer diameter
Crankshaft
Crankshaft runout : Support crankshaft at journals of
Valve clearance
Valve stem outer diameter
Valve guide inner diameter
Intake valve
Exhaust valve
Clearance between valve
guide and valve stem
Width of area contacting with
valve seat
Valve spring Free length
Cam height (both IN and EX)
Cam shaft Journal outer diameter
Camshaft runout
Compression pressure (Reference
Engine block
value) at 500 min
2-10
Item
· Measure outer diameter at 7 mm (0.28 in) above
lower end of piston skirt
· Piston clearance
Note : Measure ring end gap
at the top or bottom
Top ring
cylinder bore that is worn
Second ring
little if ring gauge is not
Oil ring
available.
both ends by using V block
-1
(rpm)
59.00 mm (2.3228 in)
58.96 mm (2.3213 in)
0.020 – 0.055 mm (0.00079 – 0.00217 in)
Top ring 0.04 – 0.08 mm (0.0016 – 0.0031 in)
Second ring 0.03 – 0.07 mm (0.0012 – 0.0028 in)
Oil ring 0.01 – 0.18 mm (0.0004 – 0.0071 in)
0.002 – 0.012 mm (0.00008 – 0.00047 in)
16.00 mm (0.6299 in)
Top ring 0.15 – 0.35 mm (0.0059 – 0.0138 in)
Second ring 0.30 – 0.50 mm (0.0118 – 0.0197 in)
Oil ring 0.20 – 0.40 mm (0.0079 – 0.0157 in)
16.01 mm (0.6303 in)
0.040 – 0.066 mm (0.00157 – 0.00260 in)
0.20 – 0.40 mm (0.0079 – 0.0157 in)
29.95 mm (1.1791 in)
To be less than 0.05 mm (0.0020 in) at both ends.
IN : Intake 0.06 – 0.14 mm (0.0024 – 0.0055 in)
EX : Exhaust 0.11 – 0.19 mm (0.0043 – 0.0075 in)
IN : Intake 5.47 mm (0.2154 in)
EX : Exhaust 5.44 mm (0.2142 in)
IN : Intake 5.50 mm (0.2165 in)
EX : Exhaust 5.50 mm (0.2165 in)
IN : Intake 0.020 – 0.044 mm (0.00079 – 0.00173 in)
EX : Exhaust 0.045 – 0.072 mm (0.00177 – 0.00283 in)
IN : Intake 0.8 mm (0.0315 in)
EX : Exhaust 0.8 mm (0.0315 in)
35.0 mm (1.38 in)
28.33 mm (1.1154 in)
Flywheel side 13.98 mm (0.5504 in)
with de-comp. 0.34 MPa (49.3 psi) [3.5 kgf/cm
without de-comp. 0.93 MPa (137.8 psi) [9.5 kgf/cm
Standard Value
2 ] ±10%
] ±10%
2
4st 4/5/6 2020