I bought my 2009 suzuki boulevard m90 back in march of this year (secondhand from springwood suzuki) and has been brilliant. However a month ago i noticed while riding along a smooth motorway that it started to feel like it was pulling, like it was going up a steep hill. This seemed to happen at cruising speeds and while accelerating. I noticed once i took my earplugs out that the engine seems to sputter/misfire, not a loud pop/bang. It has racked up24000km and i fill it up with premium fuel 95% of the time. It is in the mechincas atm getting new tires put on and i asked them to have a look at the issue, but they can't seem to work it out. They suggested a power commander type device to try and fix the problem. I would be most gratefull for any ideas about what the problem could be.