Oldsmoswede

I suspect my fuel level in fuel bowls is too high.
The air horn gasket gets saturated after running engine, or is it normal?
Carb is a Rochester 4GC 4 jet.

Tedd Thompson

How does the engine run otherwise, does it flood out at all is it intermittent? Probably a float level issue but could be a cruddy needle and seat. Time to pop the top and have a look/ measure.... Tedd

Oldsmoswede

I have been struggling with it for a while to get a clean run. It flooded at some time, replaced the spark plugs yesterday and got a quite smooth run actually. Only issue now is high idle, can’t get it down. Choke funktion is normal, also ignition settings.
I had planned to open up air horn, but when there was such a noticeable improvement in the run after plug replacement I was hoping that it wasn’t necessary to open up carb...😊

But I start to realize there might not be any other option than opening the carb...😖

Thanks for your advice 👍

oldcutlass

You may just need to tighten the carb screws a little.

Tedd Thompson

I wouldn't think just replacing the plugs would change the weeping gasket on the carb..... Tedd

Oldsmoswede

I have now lifted the air horn. One of the floats was filled with fuel....
And I noticed another thing, there wasn’t any pull clips on the needles???? See pictures of needle, are there needles that don’t require pull back clips?






I’m going to contact the company in US who sold this rebuilt Rochester to me and listen what they have to say. Just feels sad and struggling to start shipping from Sweden...☹️

Oldsmoswede

I just hoped that the improved efficiency in plugs might have helped fuel burning....😕
But it was just a wishful thought...

But now I think the problem is located, as I mentioned in this thread.


Leaking float.

Ozzie

You will need to fix that leaking secondary float. That is likely what is causing the high fuel level in the carburetor. I checked in the Rochester carburetor book. It doesn't show any "pull clips" on the needles, but it does show a "float balance spring assembly" (part 7001850) for the floats. The float level for the primary side is 1-7/16 inch; for the secondary side it is 1-3/8 inch. The float toe (primary) is 17/32 inch ; secondary is 3/8 inch. The float drop is 1-3/8 inch for the primary side and 1-1/8 inch for the secondary side.





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Oldsmoswede

Sounds interesting, do you have any pictures?
Exploded view?

Ozzie

Tedd Thompson

If you are handy with a soldering iron (or someone you know) that float should be repairable. a good epoxy may work as well...... Tedd

Oldsmoswede

Thank you Ozzie 👍👍

Oldsmoswede

The soldering iron part might be worth trying, it’s useless as it is now anyhow.
Epoxy sounds easier, just drill a hole to get all fuel out and use epoxy then?
Are there epoxy that’s fuel resistant?

I’m going to wait for the respond from the company first before doing anything. Hopefully they will solve this quickly.

Fun71

I would think solder is better. You may need to use a propane torch and soldr/flux like what you would use for copper plumbing work.

Ozzie

Whichever method of float repair you use, be sure to identify why it leaked to begin with so it doesn't do it again right away.

dragline

Brass float test

Another thing to consider is fuel pressure, some replacement pumps put out more psi than the factory recommends. This could also lead to high fuel levels.

Here is a posting from Cliff Ruggles about NEW brass floats and ethanol added gasoline. It may be solder related failure.

NEVER for any reason use a brass float, they are too heavy, and this fuel eats the solder up in them and they will sink to the bottom of the bowl.....the failure rate on the current production brass floats is 100 percent. We found this out here the hard way a few years ago, as we also rebuild AFB's and other types of carbs that use brass floats. One by one they all came back, some were out there a couple of years, some a few weeks, but every single brass float we installed failed and filled up with fuel and sank.