Need your 2 cents

I just sold a pristine 1971 6hp for $500.
My engine had little time on it and had the ignition, carb, complete water pump and new gear oil done on it.
The one you are looking at has much better ignition so that does not need to be done. If the engine idles down to a low idle and smoothly transitions to WOT then the carb is okay. Being able to achieve and maintain a low idle also indicates the compression is there. Check the gearcase for water in the oil. Find out when the last water pump was done and check to see how well it pumps.
If all these items check out and the engine has been taken care of overall then it is not a bad deal.

Sounds like a good deal if it is well maintained. Myself, I would change the water pump unless I was there to see him change it. When I purchased my last motor from my boss (Who owned a boat repair business) which he kept it in his garage the first thing I did was change the impeller. It is cheap insurance.

Thanks guys