I have been trying to break in a Fox 35, and have been having flooding problems.  I am using the very last
Fox needle assembly (the one that has the fuel delivery coming into the needle valve at an angle).  I also
noticed tha the venturi seems large.  I started looking at my stash and found two that had venturi inserts.  Were Fox 35's supplied with venturi inserts, or are the ones that I have, custom made (engines bought used).

Brew

    You may have a Fox Combat special or similar higher performance engine. I have never heard of an insert on a Fox.35 stunt engine. There is on the early .36 CS engines I believe. I have stuffed a stick into a venturi on occasion to get some extra fuel mileage out of a model with a too small tank. Maybe a picture would help us?
   Type at you later,
    Dan McEntee

Harold,
The Fox 35 does not have any inserts. If your are having flooding problems you may have the tank mounted too high on test stand. If you are using a plastic tank it is usually ticker (1 1/4") than a standard 1" tin tank. For a test stand, set the tank so the center is say a 1/4" below the spraybar. Also don't try to run it too rich. For break-in you could use a 9x5 prop (to keep the load and heat under control), with 5% nitro, 25% oil fuel (could use 50/50 syn/castor or straight castor).

Best,   DennisT