Not sure what you mean by the main weight. Do you mean the weight which balances the tonearm at the correct weight? If so we would need to know which arm is on the TT. I doubt there would be a spring in the weight at the end of a tonearm as I've never seen that and I've had a couple of Micro Seikis.
My System: Micro Seiki BL51 Turntable, Stax UA7 Tonearm, RCM Sensor Prelude Phono Stage, Ortofon MC15 Super II Cartridge, Rotel RCD865BX Cd Player, Melody I34R (Astro Black 40) amp and Osborn Epitome Speakers.