hey guys, I have been searching far and low for some progressive front fork springs to make this beast handle better. I am looking high and low but cannot find anything specifically for the 81 xs400. Help please?

Search for a company called "Wirth". I think they are a german company and they manufacture progressive springs for most bikes including the XS400. If you have no luck finding a company who imports them to the US there are quite a few on German ebay for around £75 (so around $120 mark).

http://cgi.ebay.de/WIRTH-progr-Gabelfedern-YAMAHA-XS-400-77-82_W0QQitemZ390065388760QQcmdZViewItemQQptZMotorrad_Kraftradteile?hash=item5ad1b57cd8

Caddy

hagon also make them here

also here

drewps