Santiago
Ditch those cute little lead weights and add a couple tungsten copper alloy cylinders in place. Pull will increase dramatically. Tungsten -copper is 1.5 times denser (heavier) than lead. You can get virtually any size you need from Mi-Tech Metals:
https://www.mttm.com/tungsten-...y-crankshaft-weights
Crankshaft store:
https://store.mttm.com/cranksh...396324234.1568645918
Oh, and nice job by the way.