FC420V won't start

[bertsmobile1]

Whip the rocker cover off.
You have a stuck valve, burned valve or the valve timing is off.
verify the valve timing by putting a stick in the spark plug hole and rotating the engine 2 full revolutions

 

[Harold41]

Took off the rocker cover, Spinning the engine over both valves appear to move up and down about the same amount.

At top dead center the flywheel magnet is about centered on the second leg of the coil.

At top dead center both valves appear to be seated, there's lash in the rocker arms.
Exhaust valve starts to open about 3/8 rotation, full open 3/4 rotation, closed about 1 full rotation.
Intake valve starts to open about 1 1/8 rotation, full open about 1 3/8 rotation, close about 1 3/4 rotations.

Decided to recheck compression, 105 PSI (must have not gotten it tight first time last week).
Added about 50 PSI air thru the compression tester with piston at TDC on compression stroke. Can hear a very slight leak in the crankcase and exhaust valve, none in the intake.

 

[Boudreaux In Eunice La.]

It seems to me that the valves are not adjusted correctly.........

 

[bertsmobile1]

Took off the rocker cover, Spinning the engine over both valves appear to move up and down about the same amount.

At top dead center the flywheel magnet is about centered on the second leg of the coil.

At top dead center both valves appear to be seated, there's lash in the rocker arms.
Exhaust valve starts to open about 3/8 rotation, full open 3/4 rotation, closed about 1 full rotation.
Intake valve starts to open about 1 1/8 rotation, full open about 1 3/8 rotation, close about 1 3/4 rotations.

Decided to recheck compression, 105 PSI (must have not gotten it tight first time last week).
Added about 50 PSI air thru the compression tester with piston at TDC on compression stroke. Can hear a very slight leak in the crankcase and exhaust valve, none in the intake.

We need you to translate that to piston positions.
Exhaust should open around bottom of the stroke and remain open till just past top of the stroke.
Just before the exhaust valve closes the inlet should open and remain open till the piston gets almost to the bottom then close.
On the following up stroke the inlet should open a tiny amount ( decompression ) and this can be anywhere from about 1/2 way up to almost all the way up then close again.
The inlet valve should be closed before the magnet is between the legs of the coil.
DEpending upon the chip the actual firing can be anywhere from magnets between the legs or magnet just passing the 2nd leg.

 

[Harold41]

The exhaust starts to open before the bottom of the stroke and closes at the top of the stroke.
The intake starts to open after the top of the stroke and closes well past the bottom of the stroke(about midway in the upstroke).
Decompression opens the exhaust valve a tiny amount immediately after the intake valve closes.
The intake valve is closed before the magnet gets to the coil.

I checked the valve lash a few days ago. Intake was OK, the exhaust required a very minor adjustment.