Sitting does not always cure the problem. During one episode I had 2-3 lbs of pressure after returing to the dock. I let it sit about 10 minutes and restarted and still had only 2-3 lbs. I immediately changed the filter and restarted and had approx. 50 lbs.

Over the weekend when the pressure bottomed out I was initally running 40-50 lbs at full throttle. When we slowed down I noticed, but did not see when, that the pressure had droped. We did sit for 10 minutes and on restart had about 20 lbs of pressure. There does not seem to be a consistent sequence which causes the pressure drop.

Is there any kind of flushing chemicals, like gunk, that I can run through the engine to try and resolve a potential blockage? I dont think I have a blockage becuase I can idle what seems like all day with no appreance of the pressure drop.