Timing the starting engine is as follows. To do this, rotate the flywheel until No.1 cylinder (located nearer the flywheel) is on the compression stroke an the timing mark on the magneto distributor gear lines up with the mark on the magneto housing. Remove the plug and check that the camshaft gear and magneto drive gear timing marks are aligned. Then check that the MAG mark on the flywheel is aligned with the mark on the bearing flange. If these timing gear marks are lined up. The engine is properly timed. Note: Be sure the timing marks on the crankshaft gear also lines up with the timing mark on the end of the crankshaft. Due to the two keys which prevent the crankshaft gear from rotating on the crankshaft, it is possible to install the crankshaft gear 180° out-of-time with the crankshaft and flywheel.
I hope this is of some help.