Tom, it’s your boat and wallet but an inexpensive vacuum gauge will tell the tale. I would hate to buy an expensive Yanmar pump and find out it’s something more simple unless you want a spare pump anyway. They are available on amazon or eBay and maybe 20$
https://www.generalfilters.com/products/general-fuel-oil-products/garber-filters/accessories/Filter-Restrictor-Indicator-Gauge_PT111.html Len Sent from my mobile device.
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