Re: 1960 johnson carb ? 3hp.
The fixed jet orifice must be absolutely, positively CLEAN, and if so it will run fine. The adjustable needle allows you to compensate for a bit of blockage by merely opening it up a tad. On the other hand, the fixed jet was great for the people that just couldn't grasp the basics of adjusting a carburetor. They quit putting adjustable high speed jets on cars a Llo.o.o.n.n.n.gggg time ago. Yeah, the don't even put carburetors on them any more.