My last solid roller had an eccentric shaped base circle so I did what cab said (to find the loosest spot). I then plugged that info into the 8 position chart for valve adjustments and used that. So I had to take the cylinder numbers on the chart and slide them down a coulpe and re-did the chart in Word program on my computer and printed out a bunch of copies. That way I can just check off each valve as I go with a pencil.