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I started noticing a fairly load whine and best I can tell it’s the fuel pump. Oddly I only hear after 5mph for a while, like through the marina it will start, then go away after normal boating. Not sure if anyone has had a similar issue? Only thing that makes sense to me is the anti-siphon valve may be clogged up and opens with more flow…

Anyone know how easy it is to change the ant-siphon valve on an R7?

Hi Lifelongbtr.
Although I've never changed an anti-siphon valve, I have done maintenance / a rebuild on a VP fuel pump. I was having the same symptoms you're experiencing, in that the fuel pump whine was very noticeable sometimes, and others not so much. I removed my pump, took it apart, and found small pieces of gravel/ sand in the seawater cooling lines for the fuel pump. It would be worth looking at that as well.

Thanks, I will look.

Fair warning... to get to the fuel pump on the engine is a little difficult, if you want to completely remove it. I could not find a way to remove it for inspection of debris, without also removing the coolant overflow tank, fuse block, and bracket which holds both of those things. I highly recommend using a vacuum pump to remove the antifreeze so you don't dump it into your bilge, and so you can reuse it. Assuming your engine looks very similar to mine.