I'm a bit old fashion and still use a Vibra-tach which I think runs about $40. You won't find anywhere except a small engine repair shop. Sold by B&S. It's Not electronic or digital. Takes a little bit of practice to use, but I have had mine for over 25 years. A good tech should be able to help you out. Might need to find one that has been around for awhile, the young guys may not know what it is.