OK guys’ thanks for your responses. This afternoon I figured out the problem. I had an opportunity to compare the carburetor on my OS 60FP with a carburetor off another OS 60FP engine and noted that the HSN seat (which should extend to the center of the barrel) was broken off. I am more than a little annoyed that the fellow that sold me the engine failed to mention this little fact. Sometimes those good bargains don’t work out to be as good as we expected.