It won't start

[brainbug007]

So I've got all my leaks sorted now except for the radiator. I've got the bike carbs mounted and the fuel line fitted. Bike pump runs and charges up the pressure (ran for about 30 secs slowing down till it stopped). I held the throttle open slightly with a screwdriver and tried to start the engine. It cranks and you can hear what sounds like air being released but doesn't start up. After letting it crank a bit then turning the key off, I tried again. Still no joy and after a few minutes of trying this the battery seemed to die as the battery light on the dash got really dim while cranking and it sounded like it was really struggling to crank. I took the battery off thinking it must just not have had enough charge and sure enough it was empty when I connected it up to the charger. I left it for a couple of hours till it had a good charge and tried again but with no luck. So I'm guessing enough fuel/air mixture isn't getting through from the carbs into the head or I've got no spark. Any ideas what I can check to get it going? (note I'm running a 1.8 CVH CFi with a bike carb conversion so it's distributor-less and trying to start it up in limp home mode with only the edis and no megajolt)