ok, i was setting up a procharger on my boat (502) , the carb i had for the system ran ok but was a bit lean in a few spots. i am having nickerson build me a carb, and will not have it for a week or so. i removed the carb box for the procharger system and replaced it with my old carb. i left the areomotive fuel pump i had installed for my procharger and just reduced the pressure to about 7-8 pounds. It starts, runs, and revs fine. As soon as I put it in gear( under load) it spits sputters, backfires and pretty much will not even run. if i do get it to stay running i can only idle, or a bit above or it backfires. what the hell is going on? did i knock a wire loose? i messed with different fuel pressures, but nothing helps. it would be a great running boat if i just never put in into gear. please give me some advise. if anyone out there has a msd ignition for sale for this 502 please let me know