I own two John Deere 21" trim mowers (14SB & JX75) with 6 hp kawasaki engines, 5 speed transmisson. The kawasakis are great engines. One mower is three years old with no problems with the engine or transmission. The things I had to replace were the plastic wheels on the rear. The concrete and asphalt are hell on the plastic. The plastic wheels are expensive. The only other things I had to replace was the clutch that turns the blades on, and a belt. The clutch itself was still good, it was the bearing that went bad. The next one I buy will be another John Deere. Hope this helps<p>Lawnstar