Worth seafoaming a Yammy 3000 iSE before replacing carb?

I do appreciate the advice. If the repair place can't get if fixed, why throw good money after bad?

If the SeaFoam treatment doesn't do the job, I'm probably going to recommend fuel additives be used stabilizers, to prevent varnish, as opposed to something which can actually do something about it. For a real cure, it takes pulling the carb, soaking it in solvent, and blasting open the jets with compressed air.