Lubricant for Outboard Freshwater Flush Plug

[Squidder Bidder]

I thought I'd post this here because of the exhaustive knowledge of lubricants possessed by the Ohana. My brother and I are looking for some suggestions - we have twin Mercury outboards on a new boat which is used exclusively in saltwater. Naturally, they need to be flushed with fresh water after each use.

The issue is that the threaded plug into which the connection for the freshwater flush is located is very snug and difficult to remove without the use of channel locks or similar. We were thinking about lubricating the threads to make removal and re-installation smoother/simpler, etc. The concern is that a lubricant could degrade the plug itself or the gasket etc.

Does the Ohana have any recommendations for a lubricant, (or, alternatively, advice to NOT lubricate this part)?

[thorhammer]

is this plug metal? I'd hope so. If it's metal I'd use marine bearing grease. If it's plastic, maybe PTFE (teflon grease) may be easier on it.

[Keta]

The blue evenrude grease should work.  Do not use any metal bearing antiseze.

[boon]

Does it have an o-ring on it? Be careful of degrading that. The flushing port is after the water pump so if you have a leak there it will spurt water like crazy and you'll lose cooling system pressure.

[Finest Kind]

I have a Yamaha and the fitting is plastic. If the Mercury fitting isn't plastic, it's probably aluminum. I will say DO NOT neglect flushing. My boat is on a trailer so I flush it with a water tank, like a garbage can.I have heard that the flush fitting bypasses part of the cooling system, but if you keep the boat in the water that's all you can use.This Yamaha is the first outboard I have owned in many years. (Diesels are cooled via a heat exchanger salt water never touches the inside of the engine). I ignored all the advice about daily flushing and now five years on this motor is a mess inside. Looks like new outside, inside caked with salt and corrosion. New water pump and thermostat and we will see. Meanwhile my Evinrudes and Johnsons used to run 10-12 years, never saw a fresh water flush, or a new water pump or thermostat. I see these guys strapping 3 or 4 outboards on the back of their boats, do they have any time for fishing what with all the flushing they have to do?
John

[Shark Hunter]

I'd keep a spare handy.

[Squidder Bidder]

The plug is plastic, doesn't look like it has an O-ring.

On another forum (thehulltruth) some guys recommend lubing with Quicksilver 2-4-C Marine Grease with teflon - they claim the plug goes in and out without a problem.

[Finest Kind]

Teflon seems reasonable. I like Shark Hunter's idea about having a spare plug.I don't know about your Mercury, but the fitting on my Yamaha looks flimsy and cheap. Just a plastic hose fitting. I prefer to use a muff or a barrel. Of course the boat has to be out of the water to use either. A buddy just bought a new boat in 2022 with twin 250 Yamahas. At sea trials, water was blasting out of the flush fitting on the Starboard side motor, couldn't be tightened, had to shut down the motor and the dealer had to replace the fitting. Brand new motor. Did not inspire confidence. A spare plug is cheap insurance.
John

[Shellbelly]

New water pump and thermostat and we will see.

I'd be concerned about the integrity of the metal around the cylinders and heads as well.  I had an Evinrude 80 that eventually leaked even though it was flushed regularly.  The motor was trash after that.  Luckily, the fail happened close to the ramp.