i don't really know how many i have owned but i will say over 5. They are very easy to break in and tune. Maybe the best in the business. But where it lacks is life expectancy. Maybe if you do what Powell said that would prolong life. Almost all mine when they EVER ghost flame, pull it because there is definately a problem somewhere, most of the time rod slop or crank pin were. I may even try another and put the jx rod in it to start with and see how that goes. another idea, once it looses the tight spot from the metal pinch replace the bearings. An awesome engine if they could get them to about the 6-8 gal mark consistently. To be honest i probably wouldn't run anything else if they could do that.