how to adjust Marvel carb?

[Guest rwolf]

Could someone please remind me how to adjust the Marvel carb on my 4cyl '24 Buick?

Thanks

Bob W

[Scott S]

I have a '23 4 cyl. and I learned from a 1928 Automotive Engineering book. Here is the basic method. First, close the needle valve on bottom of carb and then open about 3/4 of a turn. Then, turn the air adjustment (big screw on top) so the screw is even with the little spring that holds it in place. Next, you should start the car and warm it up.

My book then says to open the needle valve in 1/4 turn increments, stopping to make sure that the car idles and revs smoothly. When it starts to sputter, stop and maybe even turn it back a little. Mine is adjusted to a little over one turn. Next, open the air adjustment 1/4 turn at a time until the car does not run smoothly. At that point, you are close and can add a little more gas until it runs properly.

When I first did this, I wound up with the needle open about three full turns and fouled my plugs. I now have it adjusted pretty well.

I am sure that others may have some better tips for this procedure.

[junkyscott]

I'm currently working on a 1921 6 cylnder and need a float for the Marvle carb. Can you tell me if there is a sorce for them.

[Mark Shaw]

Junkyscott,

You can make a new float with three wine corks, a belt sander or grinder and a small bottle of Krazy Glue (it is not affected by modern gasolines).

Just make flats on opposite sides of the corks and glue them together. Then shape the cork like the original to fit in the float bowl. You can also use the Krazy glue to coat the new float if you like.

[junkyscott]

Thanks for the tip, I'll give it whirl, it's gotta be better than the one thats in the car.