Valve Clearance; Cylinder Compression - KYMCO Downtown 300i ABS Service Manual

3. INSPECTION/ADJUSTMENT

VALVE CLEARANCE

＊
 Inspect and adjust valve clearance
while the engine is cold (below 35℃).
Remove the seat assy and luggage box.
Remove the four bolts and then cylinder head
cover.
Turn the A.C. generator flywheel to the top
dead center (TDC) on the compression stroke
so that the "T" mark on the flywheel aligns
with the index mark on the left crankcase
cover.
Inspect and adjust valve clearance.
Valve Clearance: IN: 0.10 mm
Loosen the lock nut and adjust by turning the
adjusting nut
Special
Valve Adjuster
Feeler Gauge
＊
 Check the valve clearance again after
the lock nut is tightened.

CYLINDER COMPRESSION

Warm up the engine before compression test.
Remove the center cover and luggage box.
Remove the spark plug.
Insert a compression gauge.
Open the throttle fully and push the starter
button to test the compression.
Max. Compression: 16±2 kg/cm
If the compression is low, check for the
following:
‧Leaky valves
‧Valve clearance too small
‧Leaking cylinder head gasket
‧Worn piston rings
‧Worn piston/cylinder
If the compression is high, it indicates that
carbon deposits have accumulated on the
combustion chamber and the piston head.
3-7
EX: 0.10 mm
E012
2
- 570 rpm
Downtown 300i ABS
Cylinder Head Cover
Top Dead Center Mark
Bolts