Does the shovel have compression releases? Typically when machined for dual plugs a compression release is drilled in on the head? Shovels are very finicky about how they start. Once you flood it which is very easy to do, and or thunder jet is not dialed in you only get two options, too much fuel or not enough fuel! With carb cover off are jets squirting? Apologies if you already discussed as my back reading skills are sucking! I am also guessing that you have a crane fireball ignition system to send fire to both coils as you will need additional coil to run extra plugs. Again apologies if being Captain Obvious. I know you are an excellent mechanic but it is always tough when working on stuff you are unfamiliar with. No point of reference for what right looks like. i Would darn sure verify that petcock actually works and ensure it both allows fuel and more importantly shuts it off. Once you flood it trying repeated starts you need to shut fuel off at petcock then kick it over and over till you are sure no fuel left. It will usually hiccup right at end of fuel supply which is a good sign. Then turn petcock back on twist throttle and kick, some of them do not like a early twist of throttle but actually like a twist on simultaneous with down stroke of kicker. Choke needs to be in full upright position during starting sequence no matter winter or summer. Once bike starts take idle to 1/2 way down to cover while feathering the gas. only then can you push choke all the way down (closed) and control with throttle. It is a dance for sure. And you wonder why so few of us ran shovels.