fixing leaky carbs

[wingski]

I’ve noticed a lot of threads about leaking carburetors, and I discovered something due to you guys and U-tube. Those float valves and seats in the old carbs were not as precisely machined as newer carbs. The all metal valves weren’t bad but really need to be polished once in awhile, and the brass seats get cruddy and need to be polished as well in order to really stop fuel when the float is up. It makes sense that those two have to fit really well to cut off the inflowing gas. I used a cordless drill with a Q-tip with windshield polishing compound on it to polish the seat when it was out of the carb, but I think just regular toothpaste would work as well. Wow, what a difference. Then, I used really fine steel wool to polish the tip of the valve. Again, what a difference. When I put everything back together, no matter how hard I blew on the fuel inlet when the carb was upside-down, no air was able to get by that float valve and seat and into the float chamber.

This is an easy fix, and in the future I’m going to include it with oil changes and lubes. Maybe more often than that. Thanks for letting me share another thing I’ve learned about my A.

My reading and other chores are suffering because of the time I’m spending on my ’29 cabriolet, but I’m sure not bored. I’ll probably get the thing running about the same time as the rain starts, and my car is definetly not designed for wet weather.

Have a good one guys. Isn’t it wonderful to be learning soo much so late in life.

[Patrick L.]

Thats nice to report back. It'll be nice to hear how they work when on a vehicle.

[JDupuis]

Thanks Mike.

[Ed in Maine]

Hello Wingski, I also spend too much time having fun with my Model A. What is suffering around my house is outside maintenance, paint and caulking! I have to get back to it or I will be changing out some of the trim that has rotted! Back to your work on the carburetor, It is also important to know that the carb can be dripping from gas spilling out of the jet in throat of the carb. By design, the gas has to be very near the tip of the jet to get aspirated into the flow stream. This is why it is important to have the float level set correctly. I have seen with my car that if the car is parked on a very steep hill pointing up hill, it can overflow the jet and appear to have a bad float valve. I hope you get to enjoy the hobby many more years. Ed

[wingski]

Originally Posted by Ed in Maine

Hello Wingski, I also spend too much time having fun with my Model A. What is suffering around my house is outside maintenance, paint and caulking! I have to get back to it or I will be changing out some of the trim that has rotted! Back to your work on the carburetor, It is also important to know that the carb can be dripping from gas spilling out of the jet in throat of the carb. By design, the gas has to be very near the tip of the jet to get aspirated into the flow stream. This is why it is important to have the float level set correctly. I have seen with my car that if the car is parked on a very steep hill pointing up hill, it can overflow the jet and appear to have a bad float valve. I hope you get to enjoy the hobby many more years. Ed

Ed, I seem to have the carb leakage fixed, but I’m not sure about these dual Tillotson’s. If they turn out to be too much of a problem, I’ve got the original Zenith and intake manifold which appear to be in great shape. Supposedly the dual Tillotsons give me 10 more horsepower, but I’m not impessed with only being able to choke the front carb when cold starting. The lean/rich mixture on the front carb is adjustable from the cab, but the rear carb can only be adjusted from the engine compartment,and I don’t know how far it should be opened. 1/8, 1/4, or 1/2 turn? I guess the thing to do is ask if anybody is satisfied with the dual Tillotsons compared to the Zenith. What do you think?

[Tom Wesenberg]

Sponsored Links (Register now to hide all advertisements)

Dual carbs only help when you want more flow than one wide open Zenith can deliver, and how often do you drive wide open?

A high compression head and a counterweighted crank helps at all speeds and at all times the engine is running, so that's the first two improvements I'd add to the engine.

[BILL WILLIAMSON]

Yo' BRO Wingski,
Not trying to sound STUPID, but with a little creative GENIUS, you could set up DUAL GAV/CHOKE rods.
It would be a little "tricky" to learn to choke them simultaneously--LOL
Bro Bill

[BILL WILLIAMSON]

[QUOTE=Tom Wesenberg;1533931]Dual carbs only help when you want more flow than one wide open Zenith can deliver, and how often do you drive wide open?
Tom,
WIDE OPEN gets me the CLOSEST parking & the best SEAT at an Ice Cream Place, aptly named, "THE SCOOP"!
AND, that's "THE REST OF THE SCOOP"
Bill Oink

[old31]

Wings, thanks for the tip.