Red Line Complete Fuel System Cleaner for Motorcycles - 60102-118ml (4oz)

The problem with things like this, and reviewing them, is that I am at a total loss as to if it had any effect.My motorcycle is 20 years old, and before I bought it it spent quite a lot of time just sitting, indoors, in the dry, not being used. There is a 3 year gap in the MOT history diring which it covered about 30 miles.The problem with that is that the petrol in the carburettors (yes, it has 4 of them) evaporates and leaves behind gums and tars.It does not run quite right between 1k and 2k rpm on slight throttle inputs.This stuff did not seem to help, but then the problem may not be one of settings not dirt, the bike is 20 old, and may never had been balanced during its 19k miles.Was this a waste of money, even though it seems to have had no effect?No, because it is cheaper and easier than spending ages faffing about with setting only to then find out a fuel system cleaner was all that was needed.It certainly has not done any harm, and as it treats 20 gallons and the bike holds about 4 I will wait until I have used the lot before moving on to carb setup. Otherwise then bike pulls like a train from 3kRPm.