Yamaha MM700A Manual page 57

TROUBLESHOOTING
20)
(continued)
Engine misfires
Engine backfires
High gas consumption
Check:
Dirty carburetor
Dirty or defective inlet seat or needle
*Starting valve out of adjustment
*Incorrect carburetor adjustment
I
Check:
Poor quality fuel
Incorrect carburetor adjustment
Check:
*Insufficient oil in fuel
Poor quality fuel
*Lean carburetor mixture
Check:
Incorrect spark plug heat range
*Fuel mixture too rich
*Incorrect carburetor adjustment
Poor quality fuel
I
Check:
Incorrect carburetor adjustment
Clogged exhaust system
Loose inlet seat
Defective inlet seat gasket
Worn fuel inlet valve
Leaks at fuel line connections
*Dirty fuel inlet valve
51