With 110 engines of my own plus running in engines for other people I need one that is infinitely adjustable so I use a PSP, it is a marvel of quality. On some smaller engines I turn the throttle up to clear the rather thick retaining bars. And, there are screw holes tapped in the bars to mount real small engines on top of them. Currently there is a SuperTigre 3000 sitting in it that will be converted to Diesel as soon as I run it a little on glow to get the carb set. Ain't doin that when it's 8 degrees out.