mats

The safe easiest way to do it;
1. Start the engine and let it suck up anti freeze through the outdrive until it comes out of the exhaust. That will take care of the everything except the engine block.

2. Drain the block including the circulating pump. You never know, whether the thermostate has opened or not.

The easy safest way the do it;
1. Drain the whole engine, block incl circulating pump, all external coolers, exhaust.

2. Start the engine and suck up anti freeze through the outdrive until it comes out the exhaust.

The latter method has the advantage that if you are lucky the thermostate has opened and you get some corrosion protecting anti freeze in the block.

RedDog382

Just pull the thermostats out before starting/refilling with antifreeze.

mats

Correct. If you pull out the thermostate you will definitely get anti freeze into the block. However, you can never be sure that you don´t have some raw water in the block unless you have drained it at some stage. I think the whole engine contains some 4 gallons of water so you need a lot of anti freeze to fill it up. Also the block is a semi closed loop so if you have raw water in it , it may to some extent just be circulated around while you suck in anti freeze in the rest of the system and have anti freeze come out of the exhaust.

docmanrich37

Russ with the efi's you use a 2 stroke oil mix with gas and run in through the engines so it lubes the injectors.My mechanics hookes it upto the fuel pump and it pulls it through.It's a must he says.By the way tell Faith i said HI.LOL

gsmith9898

in my manual for the 525 efi with the closed cooling it says to take off the top hose on the sea pump, but it don't say anything about the lower hose. Is that right?

t500hps

We've been doing alot of boating, If you didn't go MIA after the Baltimore trip you could have said Hi yourself!
Tell you what......come by the house and show me how to run the 2 stroke oil into the motor and then you can say hello. (as you walk past the front door cause no way I'm letting you inside!!! )

Pismo10

Test

rich allen

I run motors on muffs with fresh water till warm. Shut down. Change oil and filter. Drain block, opening both sides.Then re-tighten fittings. At this point, sit down, till head stops spinning from head rush, and have a beer. When ready, pull hoses under exhaust manifolds to drain them as well. Then re-tighten as well. Also remove air cleaner at this time. Now,there is no water in system of any real quantity.
At this point, I go old school for me. Using the muffs again, I screw on a 6 foot piece of old garden hose.At the other end is attached a gallon jug, or even a large 2 liter soda bottle will work. It will thread itself into the hose with a little persuasion. Cut the bottom off of the bottle, making essentialy a big funnel. I secure the funnel to the side of the boat, using the rear cleat and a tie strap. When ready to go, fill the funnel ( a buddy here helps alot), but I have done it alone many times, and start the boat at idle only.. Continue pouring antifreeze into the funnel, and you will see it start coming back out through the exhaust pipes. Usually about 3 gallons, and one minute for me. Quickly pour whatever preservation oil you want to use, into that carb, ( I use mystery oil) She will start smoking and sputtering. Shut it down now. Your circulating system is now protected, as well as your internals. But your block is still empty, cuz thermostat was closed. I then remove the thermostat housing, remove the stat, and fill up the block with antifreeze till I see it filling up the intake manifold. I replace the stat, and put on a new gasket, and retighten. This has worked for me for many years, and I know there is no standing water anywhere in that motor.

East Coast B

To understand how much your engine holds, dump all the engine water into your bilge and then open your bilge plug and collect the water in a 5 gallon bucket to see how much is really in there. After running my engine up to temp using the bilge pump/antifreeze method, I emptied the engine again and came up with the same 5 gallons, this assured that the entire engine was filled with antifreeze. Again, I run the bilge pump to drive muffs for a while at idle to get engine up to temp so oil is heated up and antifreeze got into block. A bilge pump, hose, drive muffs and $3/gallon antifreeze are a cheap investment for the security of knowing it's not going to freeze up on you.