You could always buy a boat.... the people I know that have boats are constantly throwing money at them 'specially sail boats, my bud has a 40 footer with a 350 GM motor and teak decks...beautiful boat but man that thing eats money like there's no tomorrow....just to haul it out of the water and clean barnacles and change the zinc's is costing him $85 a day in dry dock fees...Couldn't f'n believe it, him and his wife sailed it up the inside passage to Alaska last year and it cost them a fortune...you think wind is free but you need the motor for electricity and gas up there's around $6.00 a gallon in places....If you don't want to be rich buy a boat !
As for your bike, soot on the plugs could be anything from a stuck choke to mice in the airbox. You need to ensure the airbox, filter and ducting is clear going into the carb, the choke is operating properly and the plugs and coil are good. Basically sooty plugs indicate a weak spark or excess fuel/insufficient air. The insufficient air and weak sparks are pretty easy to check so start there before you go tearing stuff apart..