1954 Cylinders 3 & 4 carbon fouled

[Troy P.]

Re: 1954 Cylinders 3 & 4 carbon fouled

That's the place, Jim. I remembered it has the word "black" in it somewhere.

[Troy P.]

Re: 1954 Cylinders 3 & 4 carbon fouled

You know the trick to leave the little spring off the top of the rod? The spring provides a slight side load on the rod that causes one side of the rod to wear against the jet rather than staying centered in the hole.

[Jim L.]

Re: 1954 Cylinders 3 & 4 carbon fouled

You know the trick to leave the little spring off the top of the rod? The spring provides a slight side load on the rod that causes one side of the rod to wear against the jet rather than staying centered in the hole.

I discovered that issue with my YH carbs when I rebuilt them about 15 years ago. I couldn't see any useful function being performed by that spring and I could clearly see the wear it created on the jets and the rods. I threw the springs away.

I mention my recommendation to remove (and discard) the springs almost anytime the subject of YH carbs comes up. Most of the time I get back the Internet equivalent of a blank stare. Either folks don't believe me or they don't have enough experience with the carbs to know what I'm describing. I'm glad to see that's changing.

Jim

[Troy P.]

Re: 1954 Cylinders 3 & 4 carbon fouled

Changing subject slightly but staying with fuel issues...I just rebuilt a NOS 4132 pump to use ethanol resistant diaphrams. While the pump was apart I drilled a small hole in the fuel outlet non-return valve. This was recommended in some article I read 25+ years ago to relieve the fuel pressure upon shut down and thus eliminate the dripping carbs problem. I will be interested to see if it works and if the hole maybe too large.

[David W.]

Re: 1954 Cylinders 3 & 4 carbon fouled

I, too have removed that spring from one carburetor. Don't think there has been any problem. I set the float levels at 9/16" and that seems to pretty much stop the dripping from the heat soak.

[Chris S.]

Re: 1954 Cylinders 3 & 4 carbon fouled

carbs leak regardless - it is the design........

[Troy P.]

Re: 1954 Cylinders 3 & 4 carbon fouled

What is it about the design, Chris?

Seems to me there is logic to reducing the fuel pressure in the lines upon shut down.

[Jim L.]

Re: 1954 Cylinders 3 & 4 carbon fouled

They don't all leak. The YH carbs on my '54 never have. The car doesn't have a fuel pressure regulator nor has the fuel pump been modified to bleed down the fuel pressure with the engine off.

Needle, seat, and float technology is pretty simple. I gotta believe that if the needle and seat won't withstand normal fuel pump pressure, something else is wrong besides a design flaw.

Jim

[David W.]

Re: 1954 Cylinders 3 & 4 carbon fouled

You are fortunate.

[Mark W.]

Re: 1954 Cylinders 3 & 4 carbon fouled

Troy,

I just rebuilt my 2066YH and left the springs on them. Do you think that I should go back and take the small spring off the top of the needle so that I won't get the slight wear in the next 10 or 15 years or starting it and driving it less than 1,000 miles a year will have no effect on the spring on the top of the needle since its not a long driver car and more of a show car.

Let me know your thoughts. I had same issue of spark plugs fouling out in less than 10 miles and found that the needle and seats were worn slightly and now it runs like a champ.

Mark

[Jim L.]

Re: 1954 Cylinders 3 & 4 carbon fouled

Mark, I'd take those springs off and not give them a second thought. Put'em in a baggie and pass them on to the next custodian.

It's been 20 years since I removed them from the carburetors on my '54 and I've never seen any ill effects.

Jim

[Gary H.]

Re: 1954 Cylinders 3 & 4 carbon fouled

I had a significant problem with leaking carburetors, the fix was to use a valve that had the spring(bottom). The one that comes with
most kits(top) do not have a spring. No problem since we did this!

[Chris S.]

Re: 1954 Cylinders 3 & 4 carbon fouled

Thanks Gary
Do you have a part number and a vendor?
Chris

[Gary H.]

Re: 1954 Cylinders 3 & 4 carbon fouled

Chris, Sent a PM.

[Troy P.]

Re: 1954 Cylinders 3 & 4 carbon fouled

One other thought I have from dealing with my 265 V8 fuel pump, turns out that typical rebuild kits for pumps are designed to work on a variety of pumps. So if your pump needs specific springs to provide the design pressure you may have the wrong ones.

Its worth testing the output pressure of rebuilt pumps against the spec for the 9797 and 4132. Too much pressure will lift the needles off the seats and dump extra fuel into the carb bowl, if I understand it correctly.