Certainly running rich and I agree, the evidence of possible fuel overflow (staining under the filter) points to the needle valve. Since the carburettor, at 50,000 miles, has probably never had any work done on it it may be worthwhile putting a complete kit on it. In 36 years the seals and gaskets, which were never designed to cope with ethanol blend fuel, will have deteriorated.

If you can do the work yourself it is only going to cost you about £60.

Peter

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