Re: 1967 mercury 500 impeller?
I have a 69 Merc 500 and it "pee's" at idle. I had to clear out my pee hole tube with some electrical wiring (or weed-eater wire) to get it to pee at all. I would think if it's peeing when it's got some throttle, you're doing good... just keep an eye on how hot the manifold cover is getting. At idle it should be touchable, almost cool.