Hi,

Be careful buying "bench run only" DF engines. If you don't know what you're doing, you can ruin one in less than 30 seconds. Also, for that particular engine, it was more than likely bench run many years ago. When it comes to DF engines, buy them new (even second-hand) or buy used ones only from people known and reputed to be very 'stand up' guys in the hobby. Not that the other guy will rip you off; he may just not know what he's selling....

Found this out the hard way back in the day....