For the past three years I have been searching the Internet for a Tachometer...preferable a round needle type tach for my Z710A. That is one for a 2 cylinder V-twin engine. I would guess there is no such item made for a 2 cylinder lawn tractor . So, I ended up with a digital Hardline HR-8061-2 model . This one was easy to install once I located a Instrument Pod and location on the tractor that would visibly to see. I can now stop guessing the RPMs on the engine when I mow. At full throttle I get a tach reading of 3690 rpms, and engine fluctuates from 3660-3690 rpms. I would say that would be about normal throttle setup. I prefer not to run at "red-line" throttle speed.