Hmm it would maybe appear I need to renew the fuel filter in my 1100,starts n runs fine up to 4k rpm 70mph if I sit at that speed or faster for a short time it's surging as if it's needing fuel..its fine once I drop back down to jus below 70/4k ..god knows how old the filter is..had the bike 5yrs but never got round to renewing it or the U bend hoses ..looks like a call to Motorworks later for new filter n assorted clamps n hoses...