My mountfield mb2801J was bought in June 2013 I may have unwittingly left some fuel in the bulb/carb for past 8-9 months now it will fire up but cuts out very soon after. Is it any good putting a tea spoonfull of REDEX in the fuel?? the original cost was £175 how much should I expect to pay a dealer for a repair? assuming the carb is NOT part of the 2 YEAR Warranty.? many thanks