I'll bump it for you this time: Per my service manual on the 60 jet through the 125 3 and 4 cyl engines, 120 is the recommended transition point from compression suitable for adequate combustion to "expect to have problems". So you are ok there.
-----------------
Just had a thought. If you were running and sucked up the rocks causing the engine to die, you could have partially sheared your Woodruff Key which locks the flywheel to the crankshaft, moving your timing off it's designed mark. With the mass of the flywheel being what it is......to keep the crankshaft rotating smoothly between power impulses from explosions in the combustion chamber, any abrupt stopping of the crankshaft can cause the Kinetic Energy stored in that FW to shear the Woodruff Key if the flywheel nut tension isn't adequate to hold under that stress.
1. Pop flywheel securing nut off the crankshaft. Look down in the area it was covering where the grooves were machined in the flywheel and crankshaft. If the Woodruff Key isn't PERFECTLY square, get and install a new one. I think the torque on the nut is 120 ft-lbs but you need to check it.
2. Do a Link and Sync per the manual to ensure that your timing is correct at idle....around TDC usually a few degrees ATDC, to 20-22 degrees BTDC at WOT depending on if running or if on the starter with the plugs out. Also in doing the L&S ensure the butterflies are as specified in the manual for the different throttle positions.