Just a reminder to change your filters if you aren't running a vacuum gauge. My Dahl 100 creates about a 2 inch of mercury vacuum at idle with a clean filter. I looked at it the other day because I could hear air cavitating in the pump and it was pulling something like 22. Yikes. Changed the filter, eliminated the cavitation sound (might have been drawing air at the fittings/clamps), and now I am back to 2.