Deep, glad you mention that. I have noticed that the surging also seems to take place a while after being in moderate/heavy seas. I thought, ok, the tank is stirred up and the filter is clogged. I should just change the filter-- and this does seem to help. But, resting the engine also seems to help. The last time it surged like this, I once again started to change the filter but noticed that the filter didn't look dirty, and the negative pressure gauge on the fuel didn't indicate any blockage. So, I just let the engine rest and everything was fine the next time I started the engine. Could it be a gradual build-up of suction?
As a precaution, I had my tanks cleaned. I have filled the tank with new clean fuel. I am using a 2 micron Racor filter. Still the surging persists. I have noticed some poor fuel hose connections on the filters and Algea-X device. A tiny dab of fuel is leaking from one. Could this small a leak cause such a major fuel starvation issue? Could tiny quantities of air introduced in the lines cause that? I'm also curious as to how fuel starvation could actually cause an increase in engine speed... seems like a contradiction!