If it is a 1974 year model it is from the engine family 35-45-50-55Hp.
All things on the engine was swapable to the different horse powers.
The timing on these engines should be 32 dgr BTDC at WOT (factory spec).
With the fuel nowadays I would suggest to set it at 28-30 dgr BTDC at WOT.
If there are no marks at the flywheel (0 and 36 dgr) you can make a mark for 0 (TDC) on top cylinder by using a indicator gauge at the flywheel or use a screwdriver in the top cylinder.
Look and feel when the piston is at TDC, mark it at flywheel to a referens at the block.
Count the tooth at the flywheel, divide it by 360 and multiply it with 30 if you will set the timing at 30 dgr. The result from this is how many tooth before the 0 mark (from the left) the top spark plug should spark refer to the referens at the block.
Check and set the points at 015 in, power the ignition system by the keyswitch or just with a 12V battery at top plug coil.
Set the throttle at WOT, turn the flywheel CW slowly and check when the top plug spark.
If it spark before or after the 30 dgr mark you adjust the timing by extending or shorting the timing rod. The rod that advance/retard the timing.
This is the static way to time it, you can do this with a timing light with the engine running.
You fine tune it this way and that is even better than the static way.
Use the marks at the flywheel to time with the timing light.
