Although I won't accuse him of trying to pull something over on me, but if he is open to me taking a more thorough exam or even tweak of the carb with screwdriver, my own gas, spark plug etc. to get it running right, and once I am convinced it is reliable, then I would spend $500. If he really wanted to get a good price, he should let me or other buyers check out the Bore and just about any other check needed to put them at ease and maybe spend more. At minimum check for spark and compression test. Hmmm, I need to find my Compression tester and see if he will at least permit me to pull the plug and see.