Winterize 525's
 

Just got a boat with 525's. The mechanic at the dealer showed me 2 blue plugs on each moter. They screw out amd that is supposed to winterize the boat. It does not have the pump like the others. Of course I will check the antifreeze also. Sound right?

run anti freeze thru the entire raw water side. cheap insurance
heat up the motors and make sure the thermostats let the antifreeze run thru the entire system

they are close cooling so the motors themselves are safe,,,,, i would drain the water and run some antifreeze through anyway just to be safe with the heat exchanger,,,, cheap ins

x2

dont forget the blue plug on the fuel chiller and power steering cooler

Check the closed cooling antifreeze to make sure its good to zero degrees

Exact same procedure/thought process as the 496.

Even if your engine has an air pressure system to force the water out of the engine, it's NOT good enough for FULL winterization.

Just draining the water out of a 525EFI is NOT good enough.

See this thread:
http://www.offshoreonly.com/forums/g...ing-496-a.html

The tstats are on the closed cooling side, so that is not necessary. But, mine are always warm before I fill them with antifreeze anyway because I change the oil right before I fill them up. And I use the good stuff...Banfrost. Not the cheap pink stuff.

And there are alot more than two blue plugs on these motors. There are two on each header rail alone.

OK - I am going to have a mechanic winterize the boat this winter to understand these engines. Just to educate myself - there are two plugs on the headers, one on fuel chiller and power steering cooler. Any others?

I said two on each header rail. :angry-smiley-038: But 25 got it right. :p

And I forgot to mention about fogging. Do that while you suck the antifreeze in. That's the beotch because you have to pull the fuel filter....drain half the fuel out...and fill it with 2 cycle oil. Then hook a 5 gallon bucket (full of Banfrost) up to the fresh water flush and let her run until empty. Done!

I'm no motor head by any means, but this is one thing I have always done myself. You should too. Buy some beer and get a buddy to help you.

There was a thread on here last year about using an outboard 5 gallon fuel tank plumbed into the fuel supply line, filled with fuel/stabilizer/2 cycle. I used this method last year, worked great to take care of the fuel system.

6 plugs per motor? I have only 1 on each header

My 2006 525 EFI ...6 plug ...three on this side

Work great , is how i do mine since 2006 ...

THANKS for pic

Do your self a favor and go to your dealer and buy 3-4 of those little blue plugs and the o rings. From heat cycling hot and cold they can become very brittle. You can crack them removing them and not even be aware of it. Then the thumb screw part on top cracks off leaving a water leak. Have had 2 do that on or 700's. Its cheap insurance to carry a couple in the boat.

Yup, I had some break on me. I filled the open end of the new ones with epoxy, never happened again.

I know this is a bit off topic, but stick with me. I just put a new set of CMI headers (OUCH) on my 525. Some of the fittings were different on the new headers ? I am told in about 2007 Mercury Racing decided there wasn't enough water going through the the headers. In short, I had to remove the (bypass) hoses from the header manifold to the tailpipe and plug both and drill out a restricter in the stb. side. I see in Christian's picture the bypass hose is still installed (left). I'm not sure witch engines this applies to so check with somebody knowledgeable for more info. Doug