used to work restoring roadsters, I did the electrics. clean ALL contacts in the circuit: bulb sockets, harness interconnects, etc. Once soldered an inline fuse holder to the fuse "tabs" in the fuse box to save the owner the cost of a fuse box. Clean connections will lower resistance and reduce current draw.
to remove rocker arms where "unlocking" jam nut doesn't work, get/make strong rod (I ground down end of allen wrench) that fits into rocker oil hole and lever towards cam. rocker heel will rise off pivot and you swing to side: free rocker. No need to touch adjustment. Remove rocker arm spring retainer and you can use socket and big bar to remove pivot socket.
loose valves, valve float, bent valve not fully closing; wore-out motor; valve retainer wrong depth for lash pad; lash pad caught between top of retainer and rocker arm- "extra lift"; bent valve
Hi; venturi's too big? Accelerator pump nozzle plugged. Accelerator diaphragm defective. Check valves not working. Accelerator pump is adjustable for bigger or longer "shot". Mikuni PHH carburetor service manual. "calling" from Canada