Thank you for your response. The back firing has been an issue with both engines. That's why I am suspious of the worm gears. I can't tell how much drag there should be on the tines when there is no power applied. I am thinking that maybe there is a bearing that is worn or broke that puts too much stress on the engine thus making it run hotter than normal and back firing. When the tiller is under load, it settles down, however, I don't see much action on the governor in either case? The carb linkage on the new engine is a straight pull to the carb with no spring attached. Maybe I've answered my own question?

The first thing I do when I get ready to use my rototiller is spray those engine support rods you were talking about and the little wheel on the end of the shift mechanism. I will try grinding the iron stop. The belt I have is supposed to be the correct one. My machine is still going strong. Bought it in 1983. I did replace the engine though when the crankshaft broke. I also put carbide tipped tines on it when the originals wore away to little stubs. I did have to replace the tine shroud and shift lever under warranty. But the longevity and ruggedness of the Horse rototillers doesn't negate the design problem that has been here from day one. And yes it is easier for the tiller tines to dig in when going uphill, but my soil is getting so loose that I have to push the tiller uphill because the wheels just spin in the loose dirt. I think I need tire chains, do they still sell them?

Snappers do not have the floating deck that the simplicity line does and the floating deck was the primary reason I wanted the Simplicity. The dealer I took delivery from also had Massey's but they were larger models. When I called the dealers on the simplicity site, all had switched to Snapper. I sent an e-mail to simplicity for help and they replied with an e-mail that I should try different zip codes in my area. I wrote back that it would be easier to input a larger search radius and that they should update their web site. They did not respond and have not updated their web site as of this posting. A friend who is a large user of Simplicity and Massey helped me locate a dealer.

I do not like the OP's nor any other repair method suggested so far. I would not consider any type of mastic or wedge anchors to hold threaded rods and the ledger in place. Unless the OP can grout J-Bolts into hollow CMUs to properly support the ledger or use threaded rods long enough so that they go completely through the new ledger and the CMU wall, I would consider nothing short of a column mounted on a concrete footing to support this beam end. Tapcons and mastic installed rods just don't cut it in most cases, and in most cases would not pass a code inspection without an engineer or architect's approval. Use a simple column and your worries are over. Otherwise, consider replacing the horizontal beam with a longer one...one long enough to be set into a pocket cut into the core-filled CMU wall...and your worries are over. Just my buck three-eighty.