backfires through exhaust bogs and dies

[bigstevo]

I recently put together an engine with dio reed valve, ported cylinder, copper gasket, shaved head, and built an expansion chamber using Jaguar's specs. I have a new mag and it wont run with stock cdi. I have to use supercharged cdi and they last 4 to 6 months. Plug is gapped at .024. Are all cdi,s this unreliable?