Maybe the stock needle valve that comes with the engine won't work, but the older rear needle valve that doesn't use an Oring may. It is also the same assembly that was in the older carburetors also and could be purchased separately. It's all metal, and can be attached to a metal bracket that is attached to a convenient lace on the airplane. I'm sure this has been covered before and some one may know what I'm referring to.
Type at you later,
Dan McEntee