Will this winterization short cut work on a 7.4 Horizon FWC

[wish2fish]

Your thermostat will close before it gets into all the engine !!.

Do what your manuel says to do !!. AIR DOESN'T FREEZE.


Others will chime in that are smarter than me.

I don't think this is true or the thermostat would be closed all the time during winter boating. Thermostats don't close instantly. If I understand the waterflow on my engine it gets warmed up before it reaches the thermostat and therefore wouldn't close.

Air doesn't freeze. but you are not supposed to have just air in your cooling system or you might get corrosion.

Who is manuel? is he the mechanic, gardener or what?

[Knot It]

Larry, the pink in the tank is a great idea. Do you drain the raw water system (heat exchangers, fuel cooler, manifolds, and raw water pump) first before you start the engines? Or do you just open the strainer lid and let the pink fly?

My next question is this: If I drain the raw water system, how do I ensure I get pink stuff to the impellar quick enough to keep it from burning up? If I prefill the strainer with the pink, will it "flow" down to the impellar and pump in time?

[skolbe]

I drain my motors and remove the thermostats. Then I blow out the seacock with an air compressor and close it while I am blowing it out. Then I run antifreeze through the strainer, I have a strainer cap made with a fitting hooked to a west marine kit with a hole in the top. I run 7 gallons through, I add 2 gallons once I start. It takes pretty much 5 gallons before it is spitting it out the exhaust. My dock neighbor ran 4 gallons without draining and/or removing thermostats. I asked him to oblige me, and we drained a spot on his motor. It was barely pink.

[Larry]

I drain my motors and remove the thermostats. Then I blow out the seacock with an air compressor and close it while I am blowing it out. Then I run antifreeze through the strainer, I have a strainer cap made with a fitting hooked to a west marine kit with a hole in the top. I run 7 gallons through, I add 2 gallons once I start. It takes pretty much 5 gallons before it is spitting it out the exhaust. My dock neighbor ran 4 gallons without draining and/or removing thermostats. I asked him to oblige me, and we drained a spot on his motor. It was barely pink.

This is a good method for winterizing a raw water cooled motor, but not to confuse the original question asked on the procedure for winterizing his 7.4 Horizon (these are all FWC), as this method does not apply.

To answer the question of draining anything in advance, it is not necessary, but if your manifolds are RWC, you can save some antifreeze if you pull the lower hose off (some have a drain valve at the bottom of the 90 deg fitting) and drain the remaining water. I do not have to do this as my entire system including exhaust manifolds are FWC.

If you have the strainer pre filled with antifreeze before cranking over the motor you will be fine, as it will suck from the sea strainer very quickly.

[Knot It]

Thanks for the help. I'm going to give it a try on Sunday. One other question has me wondering....do the hoses running from the engine to the water heater need to be drained or are they carrying antifreeze to and from a heat exchanger inside the water heater? Im thinking it is af but just want to be sure.

[sfergson727]

The water heater hoses should have antifreeze in them, as it uses engine coolant for the heat exchanger. At least that is the way it is on my boat with closed cooling.

[Larry]

The water heater hoses should have antifreeze in them, as it uses engine coolant for the heat exchanger. At least that is the way it is on my boat with closed cooling.

Just what Scott said!

[Knot It]

Thanks for the help guys! I really appreciate it.

[Knot It]

Well, ran into a bit of bad news today! I was all set to winterize my boat today, had all my stuff ready, and for some reason I decided to pull out the manual one last time just to be sure I was doing things right. Well, I saw the info in tha manual that said to check the antifreeze prior to winterizing. I had an anti freeze tester handy and checked the engine AF in both overflow tanks as well as in the heat exchangers and guess what!!! They only tested down to just between the 0 and the -10 degree markers. I thought my tester was bad so I borrowed a buddy's and it read the same thing. Now I gotta drain the bad AF out of the block and refill.

I went to the Western Auto store and bought some Prestone Extended Life Anti freeze/ coolant (Dex-cool compatible). I got the non diluted stuff and will mix it 50/50 as instructed. This will work...wont it?

Just for the record, I got my gen set as well as my water system and AC unit winterized so it was not a total loss. BTW, I bought a SEAflush winterization kit and it worked AWESOME on my gen....easy as pie to use and I put over 3 gallons of the pink through it in just a couple of minutes and it was pumping solid pink out of the exhaust port so Im good to go. Funny thing here is that the AF in the gen tested fine, -34+ degree protection acording to the tester.

The AC seacock does not have enough clearance above it to use the Seaflush kit so I just used a hose and a rag to get it to prime and ran it till the pink was coming out in a good solid pink color.


Now I need to find out where the plugs on my engine block(s) are and drain them and start fresh. After that, I will use my Seaflush kit on the engines and hope it goes as smooth as the gen set did. Can someone tell me where the drain plugs on the 7.4 block is? Do I need to do anything else for this process? I already know to also drain the raw water side as well and know where the drain plugs are, just wondering about the block.

I'm gonna give it another try next Saturday! Thanks again for the help.

Sammy