Has anyone else considered retrofitting a Sears SS-16 with a Honda GX670 (24 hp)? I did it several years ago and let me tell you, it is awesome. Of course you will encounter the usual problems with re-positioning the engine, possible belt length change, you probably need a new one, anyway, wiring schematics are confusing. The original schematic shown in the Sears owners manual is nothing like the required wiring for the Honda. I have a basic knowledge of wiring, so after blowing both coils off of the new engine, I opted to take it to the pros. It was summertime so the repair shop was extremely busy. They kept it a couple of months, my grass growing all the while, and then I had enough. I called them; "is my tractor running yet?" this is how they replied; "It is but we have a problem." "Such as, i replied. "We are afraid to load it to bring it to you," they said. The problem was the tractor had been sitting outside and the drive pulley had rusted. When they popped the clutch, the belt would grab the pulley, and with the added power from the 24 hp engine, it would want to head backwards. I had the solution. "I'll come and get it", and I hung the phone up.
I made a 100 lb weight that attaches to the frame in the front of the tractor. It is piece of cast steel that I picked up along the railroad track. I welded a handle on the top so that I could lift it, and it slips onto the frame and lifts off when the weight is lifted. Fast detach. The weight held the tractor down, even though I had become worried that I might have overdone the power for this size tractor. I have over-sized tires all the way round. 26 x 12 - 12 cleated Carlisles on the rear, 18 x 6.5 - 8's on the front. I made a dual actuator three point electric lift for the rear. I placed additional driving and fog lights in the grill. I had a custom made dash decal made to show the added switches for the lights and lift. I wired it to accept another switch to the rear for snow blade angle. This takes two more opposed direction actuators. One to pull, the other to push. I also reconstructed the frame for the front snow blade, added a lift cylinder, and two more opposed direction actuators fro angling the blade. These actuators are available in several lengths, lift capacities, and lift speed from Johnny Bucket, Jr. They sell for $260 to $295 each. Wiring couplers are available for $35per cylinder. Mounting brackets for $12 each.