Backfire and stalling?

MCNPathfinder said:

Hey everyone, I have a 1990 22' Cabin Cruiser with a Chevy 305 V8 in it. It's always been a real hard engine to please, but it just likes to move, none of this slow cruising crap. Yesterday was pretty rough. I've been putting premium gas in it and it seems to be running better than when I'd put mid-grade in and add the octane booster. However, yesterday it seemed like if you were stopped for more than 5 minutes you'd have to idle it in neutral for a minute or so before putting it into gear otherwise it would stall, and then once it was "warmed" up, you'd have to put it at like quarter throttle for a minute or so before going WOT. Otherwise it would hesitate and stall out.
I talked to a few people who say that it seems to be running lean, and advised me to check the choke. (It's a carbed engine). I can put it in neutral and rev it and it doesn't seem to have problems, although it did backfire once when I did that. I've never heard a V8 backfire. Even under water it sounded like someone shot a gun! I had problems with the retaining clip on the choke last year, I wonder if I'm not having the same problem again and the choke isn't actually working and stuck in it's default position now.
Any thoughts?

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MCNPathfinder said:

Awesome, I'll check/replace those as well. I was wondering about the fuel filter. The PO said he replaced it when he first got it about 2 years ago. I know on cars you're supposed to replace it what like every 15,000/30,000, but being that boat engines get run at 4,000RPMs constantly I would assume that the filters need to be replaced sooner? How often should I replace that filter? Can I do it with gas in the boat?

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