Will not die!

I've worked on Honda's off and on since the late 60's and owned a repair shop for several years. I recently bought a 1986 TRX350d. After minor fixes I got it running, had to replace ignition switch, clean carb, service....my problem is after cranking, it will not shut off... I've since stripped it of the fenders and cleaned and dielectriced ALL connections and plugs.... still it will not die.!!!... can someone help me please. I thought I knew a lot about Honda's in general but this has me stumped....
Tks