I have a stock 225 with a single barrel carb, Holley I believe, in my 72' Swinger. I have read discussions on the forum about jetting the carb up so 1 and 6 don't run so lean. How many jets would this carb have?, does the carb have to come off to change them? What would be a good size to put in? This is a street only cruiser. Thanks.

The holley 1920 is a single main jet design. Removal is not required, but you'll want to take the air filter off.

The main jet can be reached by removing the cover with the big "holley" held by 4 screws. (It will be full of gas, so use caution) Gently lift the fuel float to reveal the main jet. It can be removed with a wide blade screwdriver. The size will be stamped on the jet.

My truck runs pretty well with a 56 main jet. A 64 main jet was more gas than it would burn. I think a 60 would be about perfect for me. You may reach a different size jet depending on the condition of your engine and the weight of your car.

You may need a new gasket when you reassemble the carb to prevent leaking. I usually spray some carb cleaner through the main jet while I'm in there.

Good Luck!

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1980 Aspen 225 super six

Thanks Slant6Ram, that is just what i needed to know. My engine is very low milage(37K). I'll check the one that's in there and maybe increase it a couple of sizes.

Busboy-
I have essentially the same car- a 72 Scamp with 35k miles(ok that was last year, now it's up to 46k). Slant6Ram has outlined the procedure for you exactly. Let me add a couple of tips: use a shallow tinfoil cake pan to slide under the bowl as you unscrew it to catch the fuel - no spills this way. Also make sure the flathead screwdriver you use is exactly the right size and you use adequate pressure to unscrew it properly otherwise you'll bugger up the jet and that's not good.

I went from a #56 to a #61, primarily because that is the only size I could find locally. It knocked about 2 MPG off the top but she ran stronger and very smooth. I did notice a teeny bit of soot out of the tailpipe immediately upon starting but never any smoke and once it ran for 15 seconds no more soot. I think these carbs are too lean out of the factory and can really benefit from a bit more flow.

I recently found a cracked exhaust manifold which gave me the excuse to perform the 'super six' swap so I'm now a 2 barrel man. That 1920 one barrel ran absolutely perfect though, and will be available in the 'for sale' section next week as I clean out my garage. Good buck!
Todd

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72 Scamp 225 /6, auto, radio delete, alum super six, cold air duct, pertronix ignitor II and flame thrower, 3.23 rear, 2.25" free flow exhaust

I run a #60 in mine. It came stock with a #55 and while gas milage was great (best of 25mpg), it had a bad hesitation at take off and passing. I'd rather have a good running engine with poor milage than a poor running engine with high milage.

a # 61 in mine. runs great. ron

That hesitation off the line is one of the things I'm trying to get rid off. #60 sounds like a good place to start. I agree with you EricW, good running engine, not too concerned about the milage. Thanks for the tips everyone.

Huh? 1 and 6 sometimes run RICH from short trip driving with the choke partially closed. If you are not having any problems, leave well enough alone. If you are having a problem, then adjust/repair the choke.