Replacing Impeller on FV260

[bigbangtech]

Inherited a 93 FV260 from my dad recently. Overheated the last time they came in and the impeller needs to be replaced. (exhaust tubes melted and there is no water flow RWP outlet hose)

It's a 1-piece plastic housing raw water pump. I'm going to attempt to replace the impeller on the water myself but have a few questions that FV260 owners might be able to help with.

1) If I disconnect the inlet hose to the RWP on the FV260, will sea water rush in?

2) Will raising the stern drive prevent water from rushing in?

3) I also want to test the engine for any other problems first. Is it possible to hookup a fresh water garden hose to the engine water intake (in place of the RWP's output hose) for testing purposes? To me this makes sense, but since I don't have my dad to ask any more, I want to make sure that it somehow doesn't flood the engine through the exhaust/risers or something, if I start flowing water through the engine without starting it up first. (Raw Water Cooled 5.7, through prop exhaust)

[bigbangtech]

Well, I replaced the raw water pump on my FV260 without too much drama, and in the water to boot.

So to answer my own questions, which may help some of you out there.

1) Yes, if your FV260, or just about any merc sterndrive is in the water, disconnecting the intake hose from the raw water pump will allow water to rush in. It's not exactly a flood, and it is manageable, you just have to get the end of the hose above the water level, and that is not very hard. Just prepare and have battery cables, etc out of the way. The easiest way to accomplish this (for me at least) was to lay a thick blanket down on the engine, lay across the engine, with your head and arms pointing down the side of the exhaust manifold where the pump is. Unscrew the hose clamp from the intake hose and quickly raise above the waterline, and plug it with a medicine bottle, or whatever fits. Clamp it to make sure, and for good measure keep the end of the hose tied up above the waterline. (make sure it's the hose coming from the transom you're disconnecting,  otherwise you'll be in trouble, scrambling to get the output hose back on to the pump)

2) Raising the out-drive does not raise the intake holes higher than the waterline, so water will still pour in.

3) Haven't bothered with question #3 since I replaced the fried impeller and everything is good now.