I recently acquired a lightly used Briggs & Stratton 16-HP Vanguard V-Twin powered 10KW generator, of course, with no manual.

Fired it up once and all was fine. Decided it needed an oil and filter change. Looked online for oil capacity and found one place that stated 3 quarts for this horizontal shaft V-Twin..

Before I drained the old oil, I checked the dipstick and it read nearly to the full mark. When I drained the old oil, it sure looked to be a lot less than 3 quarts. More like one or one and a half quarts, at most.

After refilling about two and a half quarts, the dipstick seems to be reading about twice as high as the full mark. The new “clean” oil is very hard to see on the dipstick.

What is the true oil capacity of this thing?

Thanks for any help anyone can offer.