Valve Clearance Adjustment - Sym GTS 250 Service Manual

6. Cylinder Head / Valve

Valve Clearance Adjustment

Loosen Air Injection system (AI) pipe upper side
bolt (2 bolts).
Remove cylinder head cover.
Remove the cylinder head side cover.
Remove left crankcase cover, and turn the drive
face, and align the timing mark on the cam
sprocket with that of cylinder head, piston is at
TDC position.
Loosen valve clearance adjustment nuts and bolts
located on valve rocker arm.
Measure and adjust valve clearance with feeler
gauge.
After valve clearance had been adjusted to
standard value, hold adjustment bolt and then
tighten the Adjustment nut.
Standard Value: IN 0.10 ± 0.02 mm
EX 0.15 ± 0.02 mm
Install the cylinder head side cover.
Start the engine and make sure that engine oil
flows onto the cylinder head.
Stop the engine after confirmed, and then install
the cylinder head cover and AI pipe.
Caution
If lubricant does not flow to cylinder head,
engine components will be worn out seriously.
Thus, it must be confirmed.
When checking lubricant flowing condition, run
the engine in idle speed. Do not accelerate
engine speed.
6-16
To this chapter contents
3 bolts
4 bolts
Timing mark
2 bolts