okay to run engine after after oil change and before layup?

[nofacey]

.Yes.

[emilecantin]

Having had to deal with the aftermath of a fuel tank leaking in the middle of winter, I'd recommend to NOT fill it up any more than it already is. In fact, I think next time I'll even empty mine.

[s/v Jedi]

Originally Posted by Jetx

Never heard of biocides having any detrimental effect on engines. Can you explain?

It’s why every engine manufacturer recommends not to use it. It’s a contaminant of the diesel fuel from the engine’s standpoint.

Startron is different: the engine will run on it.

[rslifkin]

Originally Posted by s/v Jedi

It’s why every engine manufacturer recommends not to use it. It’s a contaminant of the diesel fuel from the engine’s standpoint.

Startron is different: the engine will run on it.

A manufacturer being conservative (because of warranty) will likely recommend against anything they haven't tested and approved. That doesn't necessarily mean something will cause a problem, it just means they're not willing to guarantee it won't.

[s/v Jedi]

Originally Posted by rslifkin

A manufacturer being conservative (because of warranty) will likely recommend against anything they haven't tested and approved. That doesn't necessarily mean something will cause a problem, it just means they're not willing to guarantee it won't.

It’s more than that. If you overdose it will result in damage to the engine. Like with medication, it means that allowable dosis equals acceptable damage considering the beneficial effects, like wiping out a bacterial infection. But when there is no infection, there is no beneficial effect for the medication and only the side effects remain.

[NYSail]

Originally Posted by valhalla360

Condensation is mostly an old wives tale to explain diesel that had water in it when you took it on or you have a leak around the fuel fill. Run the numbers and tell us how much air has to pass thru the tank to get even a cup of water. I have. If it's more than a few drops by spring, something is seriously wrong.

Gelling also, isn't a big deal unless you plan to launch mid winter. The fuel will gel if it gets cold enough but once it warms up it will re-liquify. The anti-gel is targeted for someone like a pickup owner who goes and tries to start the truck when it's been sitting outside at -20F and the fuel won't flow.

Fully agree. I store my boat with maybe a quarter tank for past 20 years. Rather put fresh fuel in every year…… There is a reason I bought a racor 500 water separator if in fact I have an issue with condensation. However must say never have had water problems. Also the anti gel is only if you are planning on using the boat in below freezing temperatures. Personally I dontlike to add anything to my fuel and in my climate in the NE I can get away with it versus the tropics.

[capt jgw]

It definitely is illegal to dump automotive af into the water. Here in Michigan DNR officers have been known to hang out at launch ramps in the early spring looking for a green plume when the engines are started the first time. Big fines.

[Cheechako]

You change the oil before storage to get rid of the acids that build up in the oil. Sitting in your bearings for months these acids potentially cause minor degradation.

So, 2 hours run time is up to you. My guess is very little acid buildup will happen, and let's face it, many people don't change the oil before storage at all and have no problems. Maybe problems from wear are a tiny bit worse many years/hours later.

For winterizing the cooling system on the hard you can simply close the seacock, put a freshwater hose in the sea strainer (lid off) with limited flow and run the engine. Or if you need freeze protection, while it's running pour in antifreeze mix.
No need to disconnect any hoses.