my f2 wont start!!!! its winter time here in michigan so its been apart getting painted but its all back together now. i been starting it about once a week just to make sure everything is running right because its almost spring and last night and today it does not want to start. its 50 degrees here today and ive started it in much colder weather than today. it will crank and sometimes it wants to start but it keeps popping really loud and last night it was shooting flames out the muffler when it popped. i pulled out the plugs and checked them all they are still okay for now but probably should be changed before summer. i regapped them all and still nothing. it just pops and stops running. it will run for like half a second then it stalls. does anyone have any ideas on what it might be? thank you

 

I'd just run through the typical stuff first. drain the bowls, get some fresh gas in the tank, get some new plugs and put them in, charge up the battery overnight so you've got plenty of cranking power. If none of that works then post up whats going on.
If you're feeling a little cheap you could always do what I did with spark plugs. I just heated the electrodes up with a propane torch until they were nice and white again after being fouled. You talking about re-gapping them causes me to wonder. The backfiring is probably because the engine is being flooded. I'd just throw in a fresh set of plugs with some fresh gas and I am pretty certain it'll take right off.