Troy-Bilt GTX20 Mower, Lawn and Garden Tractor

There is no exact complete replacement engine available for this. This has a 1-1/4" x 2-23/32" shaft, in which you can use a 1-1/8" x 3-25/32" shaft and cut it off to length or use a larger bushing to hold the clutch in place. You will also need a bronze sleeve and keyway to go up to 1-1/4" diameter. You would need to use the muffler and shields from your original engine, the air cleaner assembly will be a little different, but should not affect anything. The wiring may be slightly different as well.