Running Mercruiser 470 without outdrive

[Dave WJ]

I know I can run my 470 without the outdrive by supplying water with some pressure by a couple of different methods. I'm trying to find if the noise I have been hearing is from the outdrive or the engine. From what I have been observing I will need to run it about 1 to 2 minutes. Is this just matter of cooling the engine, or is the water needed in that short of time to keep the exhaust gases from being too hot for the exhaust plumbing? Thanks.

 

[thumpar]

Both. Just put a hose in the water inlet at the bellhousing.

 

[Dave WJ]

Thanks thumpar. I didn't give enough info for the reason for my question. I will have to hook up & move the boat from it's present location to get water to it. No biggie if that's what I need to do, but much simpler if not necessary. I would not run it long enough to get it over 120 - 130, so it doesn't seem the cooling would be an issue, would it? But I don't know if the lack of water in the exhaust for that time would cook the plumbing. Would I be taking a chance with the exhaust by running it with no water for that time? Not wanting to take a chance if it may be problems for the exhaust (although I think the flapper is already fried - gonna be checking that).

 

[thumpar]

The engine may be fine but the exhaust shutters and rubber joints when run dry can burn up. Even if the shutters are already toast I wouldn't do it. Also Since you have the aluminum block and iron head you need to be careful. They are very sensitive to heat.

 

[Dave WJ]

Thanks much. Exactly what I needed to know. Will be hauling her to the water supply.