I just got finished pulling the fuel pump up out of its boot and checked to see if there was anything rattling around in the fuel tank (there wasn't) So I went to crank it up to see if I could see what was rattling while it was idling. It turned over a few times then a loud CRACK (similar to a misfiring starter) and it died. Now all it does is turn over, and occasionally will get a small amount of fire but die. This is getting stranger by the minute. Any suggestions? Scott