1 Answer

I could not find an image but I did find written instructions. 

Instructions
1
Pull the timing gear attached to the camshaft toward you, from the engine housing, approximately 3/4 inch. This disengages the camshaft gear from the crankshaft gear. Do not fully remove the camshaft from the housing.

2
Search for the timing mark on the crankshaft. The crankshaft is attached to the two cylinder rods of the engine. Rotate the crankshaft until you find the timing mark behind the crankshaft gear. The timing mark is a horizontal-line engraved on the crankshaft just behind the gear.

3
Position the crankshaft timing gear mark as close as possible to the 12 o'clock position.

4
Mark that position on the crankshaft gear face with either a crayon or chalk. In other words, identify the single gear tooth with the crayon or chalk that aligns with the horizontal timing mark.

5
Slip the camshaft timing gear back into place. Do not disturb the position of the crankshaft gear.

6
Align the timing mark on the camshaft with the identified gear tooth of the crankshaft. The camshaft timing mark is a small round "center-punch" mark. The gear tooth directly above that mark must align into the identified gear tooth on the crankshaft.

7
Push the camshaft gear gently into position. You may have to "wiggle" the two gears to correctly align with each other.

Tips & Warnings
It may take several attempts to correctly align the timing marks. This is the most critical step in the final assembly of the engine.

Correct observation of the timing marks requires that all parts are completely clean. Oil or other debris inhibit the viewing of the timing marks.

Read more: How to Set the Timing Gear on a Briggs & Stratton 20 HP Engine | eHow.com http://www.ehow.com/how_6912820_set-stratton-20-hp-engine.html#ixzz2DjJVtK1J