Edit: question has been thoroughly answered. Thank you all for your time.
I’m currently shopping for motorcycles, and there’s one that looks like a decent buy, except some joker who didn’t read the manual is proudly proclaiming that it has a full tank of premium gas. I know there won’t be serious issues like you would find if the situation was reversed (knock, damaged pistons/valves, etc.), but my intuition tells me that this wouldn’t be good on a carbureted engine. I’m not sure, but I’m thinking you might find things like excessive carbon build up, which could of course lead to hotspots and knock with correct octane gas, or other long term reliability issues later down the line. Is my intuition correct, or would it be a decent buy as long as I flushed the tank and filled it with correct gas after I bought it?