Old Blackie been sitten 3 weeks, just tried to start and had a hell of time. Ended up having to pour gas down the carb about 10 ten times. This is 396 with a holly single inlet with vac choke. Every time I did the gas deal it lit right off but died. Every time it ran a little longer until it finally stayed running. When I worked the linkage a little dribble came out the pump, but not a good stream. The bottom of the manifold was wet, I thought it was getting gas but guess it wasn't. Acts to me like the floats were dry, why would that be? I noticed the last couple of times I used it, the garage smelled gasy for a few days. Also the dude runs rich, how to do we thin her down? Thax Al

Did it backfire or spit back through the carb the last time you drove it? It sounds like a blown power valve.

Randy, I don't recall a back fire in the recent past. But it puffed back today belched a little flame when I held the gas down, ( with gas poured in the carb) This is the first time its done this. Al

The power valve in a Holley is easy enough to check and replace. Everything you've described leads me in that direction, so I'd go ahead and replace it.

Usually, they go bad as the result of a backfire through the carb, but since it's essentially a rubber diaphragm, it may have simply worn out from use over time.