Yamaha F50F Service Manual page 286

TRBL
SHTG
Symptom 2: Engine speed at wide open throttle is low, engine speed decreases, or engine
stalls (poor acceleration or poor deceleration).
Check the battery lead connec-
tions and check that the ground
lead bolt is not loose or that it
has not come off.
Good condition?
Yes
Check the throttle position sen-
sor and idle speed control and
check that the connectors are
securely connected.
Good condition?
Yes
Check the intake manifold for
air leakage.
Air leakage?
No
Check the throttle valve for
bends and check if the throttle
valve shaft is stuck.
Good condition?
Yes
Check the compression pres-
sure.
Continued on next page.
9-13
Troubleshooting
No
Repair or replace the defective
parts.
No
Repair or replace the defective
parts.
Yes
Repair or replace the defective
parts.
No
Replace the throttle body.
6C13G11