Rain Swamped Boat - Help

[Hillbiehle]

My buddy's aluminum boat was swamped due to the recent storms in Annandale. This has resulted in the boat capsizing and the 9.9 Mercury 4 stroke being submerged on its side for several days. So far the plugs have pulled and cylinders turned (plugs removed). Before attempting to start, are there any suggestions or precautions needed? He'd like to avoid taking to a mechanic if there is a simple fix, however he doesn't want to damage the motor any further. Any thoughts or suggestions are appreciated.

[Whoaru99]

At an additional minimum I'd think change oil and any/all filters. Then I'd think drain/purge carb(s) or fuel injection. Check lower unit gear oil, etc.

[RIPN LIPS]

drain all fluids and gas is a must pull the plugs and drain.

[Valv]

When you have submerged motors, the first thing to do it to remove all plugs, drain the oil and fill motor completely with diesel fuel. Open the carburetor bowl and drain it also then fill it with some fogging oil or very oily gas mix.

This needs to be done IMMEDIATELY after recovering the motor, to avoid water and air to initiate the corrosion process.

I would do it anyway. Then change oil, new filter and run a little gas/oil mix to lubricate internals and remove moisture. Then change oil and filter again, new plugs, and run it again with standard gas.

To be on the safe side I would then do another oil/filter change and use the motor as it is.

Reason for most of this is to avoid pitting of any kind on crankshaf, camshaft and all the bearings, which will not show damage immediately but will do it later in the years.

[Hillbiehle]

Thank you all very much for the responces. This greatly helps.

[leech~~]

I just checked my buddies cabin up by Outing last weekend and we have two boats to try and refloat and get the motors going for him this coming weekend! Both are 2 cyc so not as bad as a 4 cyc.