You should be able to drop the float bowls, and remove the main jets. They're the larges, lowest ones in the float bowl. And there are sizes stamped into ea. jet. Not sure what size you'll acually end up with, but if you find something like a 160 or 180 in there, it's most likely too big.
Try asking the same ??? in the vintage section. And I think there are other forums that are Paso-centric.
Try this home-cure-all: Shove a DUC between your legs.
Present DUC: 2003 ST4S Yellow! 2001 ST2 Blue
Past DUCs: 1998 ST2, 1981 500SL Pantah, 1985 MHR Mille, 1987 Paso Limited, 1995 916 mono
Other brands (past):
1978 BMW R100RS Motosport, 1978 R100S, 1981 Moto Guzzi V50 Monza, and a long list of Hondasakizukis