[JAM1775]

if you have a friend who is handy to help you you may want to try pulling off your carb. Take off the float bowls and BLOW them out with a hefty dose of carb cleaner. Also, shoot it down the float adjustment screw holes. you could blast those holes with the carb mounted but if it is dirt you may just lodge it in the metering block. If you have the metering blocks off, hold them out in a well vented area and blast all the orifices with the carb cleaner. Of course, use the spaghetti hose at all times. If you have dirt in your carb that could cause intermittant opening or blockage of the needle/seat which would drown your motor .
You could have a dirt particle floating around your bowls which sometimes lodges in the metering block. Replace all your carb gaskets (4) plus the bottom plate gasket) before reassembly. You could "check" your power valve but for ten bucks it is almost worth just replacing it. Overall your buddy may spend 45 minutes or so and a few bucks but hopefullly you will have resolved the problem. It is a worthwhile effort that could save you money.
It just sounds like a minor carb problem that erupts to cause all the havoc. If it is a Holley, dump the stone filters and install an inline . Do you have a carb shop nearby ? They may blow it out for you. Again, as stated by others above, I am also just "assuming" it may be the carb from your description of events.