I tried to remove the steel insert from the carb body and couldn't do it, so I removed the nylon part from the steel and replaced IT instead.

The fitting presently in my carb is all medal and the new one is medal with nylon insert. So I must remove it some way.

Good luck. I have the tools but couldn't get my fitting out. I'm sure somebody here has.

I had the same problem, and am posting both my solution and the "official" one, as thanks for the link to the Tecumseh service manual, which I also found here.

I was able to get mine out by drilling it out. I started out at about 5/32" and worked up to 23/64", although I probably should've stopped one size smaller, as my hole wasn't perfectly centered and I scraped the carburetor a bit. I put some gasoline-resistant gasket sealant around the new fitting (taking care to avoid getting any in the center hole) and it hasn't leaked.

The official procedure in the Tecumseh service manual ( http://cpdonline.com/692509.pdf -- if it's down, try a few hours later), page 24, is to use a 1/4" bolt, nut, and washer as a puller, plus a 1/2" nut as a spacer to push against. Cut a 1/4" thread on the inside of the fitting with a tap, thread the nut 1" or so up the bolt, put the larger nut over the fitting, thread the bolt into the fuel fitting, and turn the nut back down to pull it out.

If you have a metric tap/die set then 6mm is the size to use. I don't have a tap/die set of any form, but had I read this before drilling it out, I would've bought a cheap set at Harbor Freight or Northern Tool, as that would be easier than drilling it out.

In either case you probably need to remove the rubber needle seat to get the metal shavings out.

Here is a link that might be useful: Tecumseh 3-11 HP service manual