so i been noticing my ct90 smokes i cant pin point where the smoke comes from i first noticed it around the seat/gas tank, then today i noticed around the engines/crankcase. its hard to tell because its a faint smoke. when i first started noticing the bike had sat all winter with stabil in it. then i rode it once and battery went bad so i finally put and new one in and got it started, the bike has been getting up to 50mph on the speedo so as far as that its running good i know my transmission or clutch could use some work because sometimes its hard to shift up or down. but anyways back to smoke possible reasons?