Yamaha F20A, Service Manual

Page: 82 / 444

3-10
INSP
ADJ
E
GENERAL
NOTE:
●
Batteries vary among manufacturers.
Consult your battery manufacturer’s
instructions.
●
First, disconnect the negative lead, then
the positive lead.
1. Check:
●
Battery fluid level
Below the minimum level mark
→
Add distilled water to the proper
level.
●
Battery fluid specific gravity
Less than 1.280
→
Recharge the bat-
tery.
Battery fluid specific gravity:
1.280 at 20 ˚C (68 ˚F)
Spark plugs
1. Inspect:
●
Electrodes 1
Cracks/excessive wear
→
Replace.
●
Insulator color 2
Distinctly different color
→
Check the engine condition.
2. Clean:
●
Spark plugs
(with a spark plug cleaner or wire
brush)
Color guide:
Medium to light tan color:
Normal
Whitish color:
●
Lean fuel mixture
●
Plugged jet(s)
●
Air leak
●
Wrong setting
Blackish color:
●
Rich mixture
●
Defective ignition system
●
Excessive idling
●
Wrong spark plug