i havent received my manual yet and i want to adjust the valves on a 250ex. can anyone help me with some info?

 

Here you go:

Inspect & check valves while engine is cold.

Remove fenders, gas tank, & heat protector (plastic under tank).

Remove the three bolts & rear crankcase sub-cover from the rear crankcase cover.

Remove the timing hole cap from the left side of the rear crankcase cover.

Remove the valve adjusting hole caps from the cylinder head cover.

Turn the crankshaft counterclockwise and align the "T" mark on the flywheel with the index mark on the rear crankcase cover.
Make sure the piston is at TDC (Top Dead Center) on the compression stroke.
This position can be obtained by confirming that there is slack in the exhaust rocker arm. If there is no slack, it is because the piston is moving through the exhaust stroke to TDC. Turn the crankshaft one full turn and match up the "T" mark again.

Check the clearance of each valve by inserting a feeler gauge between the adjusting screw and valve stem.

VALVE CLEARANCE: IN/EX 0.13mm (0.005 in)

Adjust by loosening the valve adjusting screw lock-nut and turning the adjusting screw until there is a slight drag on the feeler gauge.
Apply oil to the valve adjusting screw lock-nut threads and seating surface.
Hold the adjusting screw and tighten the lock nut.

TORQUE: 17 N.m (1.7 kgf-m, 12 lbf-ft)

After tightening the lock nut, recheck the valce clearance.

Install hole caps & tighten.

Install timing hole cap & tighten.

Install the rear crankcase sub-cover with the three bolts & tighten.

Install heat protector, gas tank, & fenders.

Hope this helps,

 

How do you know when your valves are out of wack? What makes them go bad? Is there a performance increase with the adjustment?