Parts are nearly impossible to get for these old saws if is the McCulloch as they have been out business a good number years now. If it has good compression and fires on a fuel mix prime then the carburetor is likely the root cause.
With this being 48yrs old I would not expect the gaskets will loosen without tearing. And getting a kit is best if available and you are willing to buy one as they are expensive now due they are becoming rare, plus you have to pay a premium because of the currency exchange rates.
