Well, I got the DHT 22. 90 minute drive on twisty roads in high winds and flurries, just to find that the "excellent, only used once for 10 cords" was weathered from setting outside and was certainly used more than that. Sticker has July 2014 punched out, which I interpret as the Lowes sale date. Owner had tried for 2 hrs to get it started. Blowing gas out the muffler. He kept going on about how all it needed was to have the needle freed up, and how it was in brand new condition. "never even ran it long enough to have to change the oil!" He is a person with a very positive attitude. He took the bowl off, gas all over his hands, incredibly windy and very cold, and he was just so sure it would start on the next pull. Eventually I got it for $600 and he helped me heave it on the trailer. I thought that was cheap enough I can replace the engine if needed.
I took off the carb and sprayed everywhere with carb cleaner. Put some new gas and B12 cleaner in the tank, cranked for an hour, and it started. First time ran for 10 seconds, then 50 more pulls and it ran for 30 seconds, then again for 90 seconds. Last time I tried it started on the first pull, and ran over 5 minutes. It runs okay at first, full throttle and no choke, then it gets rougher and rougher and finally quits. Trying the hydraulics kills it quickly. I made sure the ram wasn't frozen up. Dunno if there's a hyd issue or the engine just doesn't have power. I replaced the hyd filter real quick to make sure it wasn't blocked with ice or rust. Fluid was clear and looked perfect. Maybe it's still getting too much fuel. I think I'll clean out the gas tank and replace the gas line. Will an engine run on 50% B12 cleaner? I see replacement carbs aren't very costly. The spark plug is sooty black, but the gap was correct.
I did a little checking on replacement engines, and only see an identical replacement (SH265). Whenever I replaced engines on my mower and tiller I always moved up a notch or 2. If I end up needing to replace this engine, I would like to know how to get the next size bigger / better. Any suggestions?