Powr - Yamaha F2.5A Service Manual

POWR

Special service tools .....................................................................................5-1
Power unit....................................................................................................... 5-3
Checking the compression pressure .........................................................5-7
Disassembling the manual starter ............................................................. 5-7
Checking the spiral spring ......................................................................... 5-8
Assembling the manual starter ..................................................................5-8
Removing the power unit.........................................................................5-10
Cylinder head ...............................................................................................5-12
Removing the cylinder head .................................................................... 5-14
Checking the rocker arms........................................................................5-15
Checking the push rod guide................................................................... 5-15
Checking the push rods...........................................................................5-15
Checking the valve springs...................................................................... 5-15
Checking the valves ................................................................................ 5-16
Checking the valve guides....................................................................... 5-16
Replacing the valve guides...................................................................... 5-17
Checking the valve seat ..........................................................................5-18
Refacing the valve seat ...........................................................................5-18
Checking the cylinder head ..................................................................... 5-20
Installing the valves ................................................................................. 5-21
Cylinder block ..............................................................................................5-22
Disassembling the cylinder body ............................................................. 5-24
Checking the piston diameter .................................................................. 5-24
Checking the cylinder bore ...................................................................... 5-25
Checking the piston clearance ................................................................5-25
Checking the piston rings ........................................................................5-25
Checking the piston ring grooves ............................................................ 5-26
Checking the piston ring side clearance.................................................. 5-26
Checking the piston pin boss bore .......................................................... 5-26
Checking the piston pin ...........................................................................5-27
Checking the connecting rod small end inside diameter ......................... 5-27
Checking the connecting rod big end side clearance ..............................5-27
Checking the crankshaft ..........................................................................5-27
Checking the crankpin oil clearance........................................................ 5-28
Checking the camshaft ............................................................................5-29
Checking the valve lifters.........................................................................5-30
Checking the oil splasher gear ................................................................5-30
Disassembling the cylinder block ............................................................ 5-30
Assembling the cylinder block .................................................................5-31
Disassembling the crankcase.................................................................. 5-31
Checking the oil seal housing.................................................................. 5-32
Assembling the crankcase....................................................................... 5-32
Assembling the piston and cylinder block................................................ 5-33
Installing the power unit...........................................................................5-36
69M3E11
Power unit
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