Mate...it's a shame no-one has replied to you yet...perhaps your Q; would be better in the Classic Bullet section.
Anyways...I have electronic ignition timing on my bike, and to adjust the timing without having contact points to visually aid the situation was a bit of trial and error- it takes some time perhaps, and a few adjustments back and forth with the timing plate, ( and there is a trick to doing that!) before you'll get it just right.
Try like this...if your Bullet is backfiring at start up, check your manual to see if that means that your timing is either too far retarded or advanced. ( I'm not sure and don't have the manual in front of me.) Then, perhaps you should slightly adjust the timing plate ( advance or retard ) to either the left or right, before setting the carb. An adjustment should be slight, not swinging the plate all the way to the opposite side!
To make a fine and very small adjustment, loosen off the 2 bolts that hold the timing plate in place, not too loose, and one at a time; then hand pinch them back so they are holding the plate without it moving easily. Then, with a flat screwdriver sitting in the notch,tap it slightly making the plate move SLIGHTLY to advance or retard the timing.
(If this first setting doesn't work out later, then you will just start again from step #1)
After this small and slight adjustment, don't tighten up those 2 bolts, just make sure they are hand pinched....and leave the cover off.
Then, you really need to have the carberettor adjusted as best as you can get it. These details of setting the carb should also be in your manual, or can be got off the Royal Enfield Bullet manual available on the internet.
Once this is done, and hopefully you can get it to run at least without cutting out from backfiring, you can then fine adjust the timing again by tapping the plate a little more to the left or/and right with the screwdriver (I use a rubber handled screwdriver and a small hammer to tap it with) - and this can be done while the engine is ticking over, so you may need to warm up the engine for a couple of minutes first, and if you have to ( until the timing is just right ), notch up your idling revs a little by turning the idling screw on the carb as much as necessary to stop it from cutting out ). The point of adjusting the timing plate while ticking over the engine, is to find the sweetest sound of your engine where it's purring,not coughing! If/when it does that, she's set pretty good.
Now, having the electronic ignition timing, and without the contact points, it is my understanding that the ammeter will not work quite as it would if you had the points; (at least it doesn't work on mine) so basically, before kick-starting the bike over, you need to get the TDC position by basically LISTENING to the engine; while slowly cranking it over at the same time. With the decrompressor switch engaged, slowly crank the motor over until you hear a swoosh sound, and just a very slight crank after that it makes another quieter hiss. The engine is now at TDC ( or somewhere close to it!) You can also check this ( and would be a good idea to get used to this method, so you'll know better where to find exact TDC by sound ) by taking off the tappet rod adjustment cover on the right side of the engine, and when you think you are at TDC, check to see that the tappet rods are set correctly. If they are not in the correct position,you are also not at TDC; then observe them while you hand crank the engine over again,( and listening ) with the decrompressor switch engaged. The front rod (exhaust) will rise up, then be the first to come back down....and just a little way behind it, the rear rod ( inlet ) will follow. A position JUST AFTER the rear rod hits the bottom is TDC, and when both rods should be able to be thumb twisted at cold.
I find to start my engine at cold, I don't use the choke,( but it is pretty warm at this time of year). When I kick over the engine to start, I hold the throttle steady at just a pinch on from off...just letting a small amount of gasoline into the carb, otherwise mine can kick back...but if i adhere to this starting method, I have no problems at all.
As for any problems with your electronic starter...i have no ideas, as my bike is only kickstarting.
ps...Don't forget to TIGHTEN up the plate ( with the 2 screws ) before putting the plate cover back on the bike.
pps...sorry my explanation was so long-winded, but it's really just a few trials and tribulations to get it all set right.
Hope this helps...I'm no expert, but do all my work my-self so far, and this worked for me...since I set my timing like that,I've ridden nearly 1000 miles running in, and the timing seems to be set perfectly, as she runs like a dream.
i also had initial problems with back-firing and cutting out, no tick-over etc, and after firstly adjusting every thing, i found that the problem was actually crap in the carb....so once that was cleaned, I needed to set the timing properly again....but I learnt a lot, so all is good.
GGOD LUCK.....Phil