1963 Runs rough, backfire/stalls until warmed up

[Profess or]

1963. Was sitting for two years. Had about a quarter tank of gas in it. Filled up with premium, 104 and carb cleaner. Runs rougher, than it did before. occasional backfires and stalls until completely warm. Needs mufflers replaced. could it be sludge working its way through?

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[biddle]

Short summary for your title "1963. Filled up with premium, 104 and carb cleaner. Runs rougher, occasional backfire and stalls until completely warm." changed to "1963 Runs rough, backfire/stalls until warmed up"

 

[inspector]

Your 1/4 tank of gas may have had a lot of water in.

 

[64ZCODE]

Sounds like a carb problem. Get a carb rebuild kit and rebuild at least the float bowls. Also there is a fuel filter in the fuel pump and you may have one in line to the carb. Clean and/or replace those.

 

[Hadderz]

Agree with inspector and @64ZCODE that there was possibly more than old fuel in the tank and this is causing the issues. Recently had the same with clumps of what I presume was laquer (dried up fuel) and brown water got throught the filters and into the carb eventually completely blocking the filter. Caused sticking floats so had to remove the tank and have it chemically cleaned out.

 

[74 Harley]

While I do agree with the other comments here, if the car runs decent once fully warmed up your choke may not be adjusted correctly. Water or other fuel problems will not go away once warmed up.