took the 1150 adv in to rainbow last week for the 12000 mile service, everything ok, been out for a run this morn evrything ok,then i put a tenner`s worth of fuel in from a cheap garage and after about forty miles it started to run a little strange., in third going through the revs between 3 and 6 thousand a slight fluttering same again in forth and fifth but only in the top end of the rev range ... i thought nothing of it at first, but then it was hunting a little bit if i kept it at constant lower revs, now am not an expert but it felt to me like the fuel but i dont know,any opinions would be greatley recieved other than that it may be the other leg lifted by rainbow?????
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