I had just aquired a 81 xs550L with 12,000 miles second owner. It has run every yr,. But as I looked at her she started very hard. Full choke for quit a while . Carbs had been rebuilt several yrs ago and synked but I found bad gas in Bowls and in tank. Put in fresh fuel and Quick shot/P.I. From Amsoil and seams to be helping out. Plugs are blk but not wet.Not sure how carbs react to sitting. I also have a 82 XJ650 Maxum (27,00 miles)and a vn750 Kaw. (34,000)They all have the same looking carbs but still would like to know about this model. Thanks for having your forum. It is a great form of info. Steve B. T-1 Certified Amsoil Dealer