Yamaha F90D User Manual

POWR
Power unit
5-27
6D81G11
6. Remove the intake and exhaust valves.
NOTE:
Be sure to keep the valves, springs, and
other parts in the order as they were
removed.
Checking the valve lifters
1. Check the valve lifters for damage,
scratches, or wear. Replace if necessary.
Checking the valve springs
1. Measure the valve spring free length
a
.
Replace if below specification.
2. Measure the valve spring tilt
b
. Replace
if above specification.
Checking the valves
1. Check the valve face for pitting or wear.
Replace if necessary.
2. Measure the valve margin thickness
a
.
Replace if out of specification.
3. Measure the valve stem diameter
b
.
Replace if out of specification.
Valve spring compressor
8
:
YM-01253
Valve spring compressor attachment
9
:
YB-06320
Valve spring free length
a
:
53.20 mm (2.0945 in)
Valve spring tilt limit
b
:
2.6 mm (0.10 in)
Valve margin thickness
a
:
Intake:
0.80–1.20 mm
(0.0315–0.0472 in)
Exhaust:
1.00–1.40 mm
(0.0394–0.0551 in)

Yamaha F90D Specifications

General

Fuel Induction System	Electronic Fuel Injection (EFI)
Starting System	Electric
Alternator Output at W.O.T.	35 Amp
Lubrication System	Wet Sump
Full Throttle RPM Range	5000 - 6000 rpm
Steering	Remote
Trim Method	Power Trim and Tilt
Exhaust	Through Propeller
Engine Type	4-Stroke
Displacement	1832 cc
Max Output	90 hp
Recommended Fuel	Regular Unleaded (Minimum Pump Octane 87)
Recommended Engine Oil	Yamalube 4M
Ignition System	TCI
Cooling System	Water Cooled
Shaft Length	L (20"), X (25")