Reply To: Weak spark on 1973 20 Hp Johnson

[Don]

Sometimes these engine have an intake manifold with a restricted/small diameter inlet. Installing the larger throat 25hp carb might not work out very well…Not saying it won’t work, but you should have a look at the intake manifold and carburetor throat first. It’s not always as simple as the seller claims… How much does he want for this “core”? I wouldn’t pay too much for it, consider it a gamble that might not work out.
I would get the engine running properly with its original carburetor first before attempting to swap out the carbs…