51 Henry J Carburetor gasket issues

[MikeZ]

My Carburetor is listed as a Carter YF 820S, SA, SB. It is a Carter YF in any event. Not sure about the rest.

The car runs great once it gets going but it runs very rough at idle and puts out exhaust loaded up with carbon.

I have had the carburetor rebuilt about every 9 months to a year. 3 times.

My carburetor guy says the gas we use now days (in California?) eats the gaskets up, especially the diaphragm pump gasket. The last time it was rebuilt, he told me to use only Standard Oil or Shell gas because of the additives they use. He also suggested using Marvel Mystery oil each time I fill up. He also told me I don't drive the car enough to keep everything running smoothly which is probably true but I can't see how that would affect the gaskets.

Well, old Henry is acting up again! My carburetor guy suggested that replacing the carburetor with a Weber carburetor may solve the gasket issue since they're made differently. I hate to not use the original carb but replacing the rubber gaskets is getting kind of expensive. The conversion kit and Weber carb are also kind of expensive.

Has any one else had this problem?

I am open to any and all suggestions. How about you Fid?

Mike

[Fid]

I did have to change the accelerator pump diaphragm in one of  my cars but only once.  I always run non-oxygenated gasoline in my cars and I drive them regularly in the summer. Sorry, that's all I have on that topic.

[MarkH]

If you swap carbs make sure you're installing one that's designed to flow the same CFM your engine needs or you'll be trading one set of poor running qualities for another, especially at low speeds.

You might also find straight gas somewhere nearby listed on this site: https://www.pure-gas.org/

[Terry T]

I have been running local gas in both my Kaisers with YF carbs that have been rebuilt with "todays" kits.
No problems in 10 years, 18,000 miles, other than a perforation, small hole, in one accelerator pump.  Symptom was black smoke.  A new accel. pump corrected the problem.  No need to rebuild complete carb.

I am friends with an old timer who worked for Carter.  A perforation is rare, but happens and is not due to the gas, but rather a flaw in the rubber.

[Corsairdeluxe]

I hope this comes across as a helpful comment. It is not intended to be critical of any individual only to show that carburetor rebuild is a deeper subject than most folks realize. Like a lot of things it is really easy to do a bad job and not be aware of it.

Most anyone can replace the parts in a HJ carb. Does that constitute a  rebuild? Few if any average hobbyist's know what the specific part is supposed to do or how to check Them. For example,Almost none know that excessive wear around the throttle rod will allow excessive air intake and make a good idle impossible. a good shop will check and knurl or replace the rod .
Granted the accelerator pump followed by the fuel level valve are the major bad actors, but hard to find problems are seldom solved by a simple kit replacement.

In this case.

Did you replace the idle Jets?
Did you soak the parts in carb cleaner and blow out with compressed air?
Did you pay close attention to the small ball check valves?
Did you use a carb gasket that allows manifold vacuum to reach the port on the carb base?

Most certainly your carb was rebuilt ,probably several times ,previously. You can not assume it was done correctly. Check the placement of the springs on the acceleratot pump and the placement or presence of the small ball check valves.

[MikeZ]

Hello there Corsairdelux,
Your comments were taken as you intended them and I will share the information with Bill at Pacific Carburetor. I'm pretty sure he covered all the items you mentioned and he charged me enough that he damn sure should have. Thanks for taking the time to write all that down. I'm always interested to here another person's opinion!
I think the comments about non-oxygenated gasoline are more to the point in my case. I think I'll look into that, but have no idea where I can buy it at this point.

I'm really surprised to hear that no one else in the club has had a problem like this.
Thanks for all the input guys! I always feel a little bad about asking questions but never being able to contribute any answers!

[Corsairdeluxe]

Try asking around at boat dealers or marinas. They will probably know if there is any good gas available in your area.We are blessed with the stuff. It's all 93 octane and about $3.25 a gallon.

[alohagreen]

And or small airports, nephew buys avgas ALL the time for his street rod.
good for mixing NOT STRAIGHT