Motorcycle Repair: loss of power and backfire, suzuki marauder 800, rich fuel mixture

Question
I have a 2001 Suzuki Marauder 800.  I had a 100 mile ride yesterday and the bike road great with speeds of 35-55 mph.  On the way home I decided to take the freeway, for the first time.  I reached a speed of 70 mph and the bike stated backfiring when rolling off throttle and major loss of power.  It never died on me and when I got home restarted just fine.  This is a fairly new bike to me, 4 months.

Answer
High speed misfiring usually indicates a too rich fuel mixture, which can be caused by a plugged air filter, incorrect carb jetting or the need for a tuneup. Swipe your finger inside the rear of the muffler once the bike has cooled down; if your finger comes out coated with a black, fluffy powder it means the motor is probably running too rich.

Check the air filter first, if that is okay then you will need to get the bike into a shop for a tuneup.