Ignition advance for a Marine engine is of particular importance. The wrong curve, and/or TA (total advance) coming on too soon, etc. could be damaging to your expensive Marine engine.
Springs being on the heavy side will seldom cause engine damage, but will hold back power. Conversely, springs that may be on the lighter side, will cause a detrimental change to the advance curve.... possibly causing Detonation issues as a result of the advance curve being incorrect, and TA occurring too early.
"Detonation" is one of a Marine gasser's worst enemies!
I'd strongly suggest that you have your distributor set up by a qualified technician, and on an old school distributor machine.
They are out there, and can be found!
(this is showing an automotive distributor..... but works as well for Marine)
The Technian will check the curve and limit, and will make any corrections, making certain that these are well within specs for your Marine engine.
You will need to provide these OEM specs for him!
Point being...... do not simply make changes to your Marine ignition advance without first knowing precisely what you are doing..... followed by a means of verifying this......
hence, the Distributor Machine.
And always check TA after having set BASE advance!
BASE means very little compared to that of the correct Curve and TA.