G'day MickyD and wce
If it was me I'd be removing all the fuel from the tank and carby and run the motor on start ya bastard ,
with the air cleaner off spray the fluid into the carby then when the motor starts keep spraying enough fluid
so the motor runs on the starter fluid for 20 seconds or longer if more than 20 seconds was when you previously
had the misfire.
Doing this will tell you if it's mechanical or fuel related.
Cheers
Max.
