RE: how do i connect a srvo to my engine
you need a pushrod with a guide tube to get past the fuel tank and through the fire wall, so it doesn't rub on the tank,the pushrod can be the stiff wire type, or the flexable cable type, either one works well.
after drilling a small hole in the firewall CA,or epoxy the guide tubeat the firewall so it stays in place,make sure the push rod is lined up with the throttle lever on the carb so there is smooth operation of the rod/cable,depending on the framing in the fuse and your servo location you might need a second hole in the next former also to line up the push rod with the throttle servo location,key is get past the fuel tank and smooth operation of the throttle push rod.