JLG X23J - X700AJ Service Manual - Manual (Page 167)

SECTION 3 - CHASSIS & TURNTABLE
3-140 – JLG Lift – 3121448
ENGINE SPEED DOES NOT INCREASE OR
STABILIZE
Check the air cleaner element. Clean the air cleaner element.
Check the valve clearance.
Remove the spark plug and check the
electrodes for carbon and propergap
.
Check the main jet for blockage.
Check for secondary air entering. Is it
normal?.
Check the cylinder compression.
Check the valve clearance.
Check that the cylinder head is correctly
tightened.
Check for defective cylinder head gasket,
valves, or valve seats.
Check for worn piston, piston rings, or
cylinder.
Check for carbon deposits in the combustion
chamber .
Check around the air intake joint and
carburetor; replace the insulator and/or
gasket if necessary.
Disassemble and clean the carburetor
.
Inspect the spark plug and adjust the spark
plug gap. Replace if necessary
.
Adjust the valve clearance.
Clogged
Abnormal
Abnormal
Clogged
No
High cylinder
compression
Low cylinder
compression
Yes
Clear
Normal
Normal
Clean
Normal