my 87 1000honda hurricane was fine till the other day it took a while to start at first then when i shut it off it didnt want to start ,, but now its sputering and missing from 1000 to 5000rpm it pulls fine on the top end.. i rode it 7000klms this year no problems so i thought better change the plugs... but its still missing could it be a bad coil maybe yup i put gasline antifreeze in it and toped the tank with new fuel and rode it hard but its doing the same thing im thinking a coil is weak how can i check this at home..any ideas..thanks