View Full Version : Winterization Procedure

08-23-2004, 11:04 AM
I just purchased my first Mastercraft this spring - a 1992 Pro Sport 205. As we approach the end of summer, I would like to get some opinions on how Winterize the boat. I live in Wisconsin and the winters are cold so I want to make sure I do a good job. Does anyone have a step by step procedure for winterizing - I am obviously most concerned about getting all of the water out of the motor.



east tx skier
08-23-2004, 11:32 AM
If you look in the maintenance archives on the old board, Jim N posted one. There's also a good article on it on www.aquaskier.com that, if memory serves is from MasterCraft.

08-23-2004, 12:12 PM

Here's a list and procedure I put together for myself and some friends. I had to .txt it to make it small enough to upload, so sorry for the formatting. Its pretty thorough and I'll admit I don't do everything every year. I got some feedback not to spray everything with silicone, but some people still reco that. The bare minimum is to fog the engine and drain the water from the block. A lot of people don't fill it w/ AF, but I do it for 1) corrosion resistance and 2) piece of mind -- any water in there after draining the block has been mixed in with the anti-freeze. By the way, if you're in WI, you may want to use stronger than 50/50 mix on the AF.

One watchout -- if you use this method, make sure you have a good connection between the engine hoses and the hoses going to your bucket -- I've blown a connection and ended up spewing hot A/F all over. Makes for a good reason to hose down the interior :)

08-23-2004, 01:44 PM
I have always used my local MC dealer for winterization. They do all the fluid changes and winterize for about $175. In four years, I have never had a problem and it starts right up in the spring. They tell me that they usually get a couple of boats every spring with cracked blocks from people that didn't get all of the water out. It's worth it for me.
If my dealer weren't so close I would probably do it myself but I'm not very mechanically inclined.
They also make recommendations for preventative maint. and do all the work.

08-30-2004, 12:03 PM

Should answer any questions you have.

08-30-2004, 12:44 PM
Because I'm paranoid I won't wait until the thermost is open (waiting till temp is 140/160) - I pull my thermostat, drain the block, then start motor to run the anti-freeze through the block. After I have sucked 5 gallons of anti-freeze through the motor, I re-insert thermostat & re-drain block.

Also - on my check-list, I have a list of every tool I need at the top, then also list each tool needed on the line it's needed. That saves from grabing both the 9/16 & 5/8" wrenches when only the 5/8 is needed, etc.

list looks good though. Especially the part about taping the exhaust & jacking up the trailer for the tires.

east tx skier
08-30-2004, 12:46 PM
Good info. I have a couple of questions though?

1. My drain plug is near the front of my bilge. Although raising the bow is good for getting the water from the ski locker to the bilge, lowering the bow would seem to be more effective at draining most of the water, correct?

2. No reference is made to flushing with antifreeze on raw water-cooled engines. I've always heard mixed reviews as to whether this was really necessary (especially in Texas), but have also heard it helps prevent corrosion in the block. My local dealer has always put antifreeze in my block for winter storage (not a MC dealer). Is it MC's position that the use of antifreeze is not necessary for raw water-cooled engines?

3. And this may be a dumb question, but ... Assuming I do put antifreeze in there, I wouldn't be leaving the engine/manifold plugs out, right?


08-30-2004, 12:57 PM

You are correct about the bow position...I would move it in whatever direction that would drain best. Most MC's have rear drain plugs so I believe that is where the comment came from and the procedure is outlined for all models (generic).

As to the great debate over anti-freeze...we use it here as it does get cold enough to freeze blocks solid and we believe that it does aid in decreasing corrosion.

We put the plugs back in and fill the engine with the anti-freeze/water solution. Since it is "enviro" friendly there is no worry at start up time and no mess in the bilge.

08-30-2004, 12:59 PM
I like the added re-assurance of knowing that I not only drained the water out, but put anti-freeze in it's place "just in case all the water didn't drain out".

Also - I put all plugs back where they belong. Theoritically I could drop the boat in & go in the spring (although I do have a de-winterization procedure which involves removing the spark plugs).

east tx skier
08-30-2004, 02:12 PM
Thanks for the replies. Is any propylene glycol (sp) anti freeze "enviro friendly"?

08-30-2004, 02:24 PM
Don't think so Doug...and I would worry about the enviro friendly version in blocks that are aluminum.

08-30-2004, 02:26 PM
I have been using Prestone LowTox Antifreeze/Coolant.
They claim propylene glycol is "less" toxic than conventional ethylene glycol antifreeze.
While I try, not to spill or lose any, I know a small amount can get lost on the ground. I dont want the family pets or neighborhood pets to get poisoned.

I know some people use RV antifreeze. Only problem with that is it does not offer corossion protection.

By the way, I use propylene glycol 100%, knowing somewhere in the system is a pocket of water I may have not gotten out and want to keep the mixture at 50% or higher.

08-30-2004, 03:20 PM
While the "low tox" antifreeze is safer for cats, dogs, and fish it certaintly isn't healthy. I'd hope that you guys are recovering it, vs. just flushing it into the lake when you start up in the spring. I do it every year -- just drain it into the bilge and collect it in a 5 gal bucket through the drain plug. Most radiator shops (Midas, etc.) will take it off of your hands, if not keep it and use it the next year. I use mine for three winters and then recycle it.

As far as the question on what makes the safe stuff safe, All of the low tox antifreezes are propylene glycol (vs. ethylene glycol), but I'm not positive that just being propylene glycol makes them safe, as certain corrosion inhibitors, etc. could affect the toxicity as well.

08-30-2004, 03:28 PM
I for one recover mine. I use to top off the old car, and have a few gallons stored up in the shed, guess I need to drop it off at the auto parts store someday.

I let someone use my boat ramp one day and noticed when he started his engine, a green cloud float to the surface. :mad: My kids were swimming just on the other side of the dock. :mad: Needless to say I gave him a piece of my mind, and he hasn’t used my ramp since.

I hope people like him are the minority.

08-30-2004, 05:02 PM
All you ever wanted to know about the glycol sisters: http://www.atsdr.cdc.gov/toxprofiles/phs96.html

More than one EPA report lists propylene glycol as an inert substance in such things as fertilizer. It is also classified by the Food and Drug Administration as an approved food additive. Consumption however is limited to 25mg per kilo of body mass, so don’t eat too much of it.

Propylene glycol is the same stuff that is used as a deicing agent on aircraft all over this country, and has been approved for use in all GM vehicles without voiding the warranty.

I'm not advocating dumping this stuff everywhere you go...but it is much safer than ethylene glycol!

east tx skier
08-30-2004, 05:05 PM
Good info! Thanks.

/propylene glycol - it's what's for dinner. ;)

08-30-2004, 05:22 PM
Good thing you don't take any chances with those cold Texas winter!Bbrrrrr!


east tx skier
08-30-2004, 05:35 PM
Yeah, I seriously doubt I'm in much danger of freezing it if it's properly drained, but it's probably good insurance anyway. And, of course, it will be disposed of properly.

08-30-2004, 09:02 PM
Don't they use propylene glycol for the coloring in Mountain Dew?

08-31-2004, 05:56 AM
If that's the case, JimN, is propylene glycol the coloring for Code Orange? Maybe that explains my buzz in the after-noons at work.....

Tom Wortham
08-31-2004, 04:11 PM
While we are on the subject.. of uses for proylene glycol... For you Cigar smokers and Humidor owners... the liquid substance that cigar shops sell you to put in your humidifying device inside your humidor is made of 50/50 propylene glycol and distilled water. It holds the moisture inside your humidor... Keeps the cigars nice and "furry". :woohoo:

09-08-2004, 03:36 PM
This topic will be very useful in a short time for a lot of us!
I just thaught that i would add something i learn doing this winterization process twice with my skiboat mechanic who does on your spot service.Really good mechanic (MC Certified)but a bit non-careful,he was spilling antifreeze on the carpet.
So,last year i bought one of those cheap blue tarp and cut a hole for the engine and left enough material to made some flaps that were hanging over the bilge,protecting the carpet when doing any maintenance like winterization or oil changes.Any fluids drop will run to the bilge.I also take out completely the rear seat,all seat cushions and the engine box to have more room and to not get anythings sratch from putting tools or anything dirty on them.
Hope this save someone a mess... :twocents:

east tx skier
09-08-2004, 04:18 PM
Really good idea, Andre. Just bought a few supplies today so I wouldn't be caught unaware when it finally gets cold enough around here to start thinking about it. Included in my supplies is a pump for faster oil changes and tranny fluid change. I'll add a tarp to my list. Thanks for the idea.

10-04-2006, 08:54 PM
how do you get the antifreeze in the engine. My freshwater hose is stuck on the intake. Do you remove that and stick it in the bucket?

10-04-2006, 10:48 PM
You're really digging deep for this thread, aren't you?

Go out and buy a piece of hose that fits onto the hull side of your raw water pump- don't use a Fake-A-Lake for this. Personally, I don't like them at all. Use a hose clamp to hold the hose on and get a 5 gallon bucket or larger- I like to run the motor at higher than idle at times and a 5 gallon is too small for this. A 20 gallon garbage comtainer is a good size and costs about $8 if you shop around. Put your garden hose in the container and fill it, letting the water continue to run. Make sure you have some kind of valve at the container and once the motor reaches normal operating temperature, shut the water off and let the motor pull the rest of the water into the raw water pump until it's empty. Shut the motor off and let it sit for a few minutes to equalize the temperature in the motor, pouring the RV anti-freeze into the container. Make sure you have your fogging oil in the boat and get back in so you can start the motor again. Start it and while the raw water pump pulls the anti-freeze into the motor, spray the fogging oil into the throttle body or carb until you see a lot of smoke. By this time, the antifreeze should be gone and you can shut the motor off. I recommend replacing the motor petcocks with brass plugs and once the motor is off, remove both plugs briefly to collect some of the liquid in the block. If it's pink, you should be OK. If it's clear, you need more anti-freeze.

One thing that's important- if the air temperature is really low and the anti-freeze is also really cold, the thermostat won't open properly and will probably close as soon as the cold liquid hits it, so keep the anti-freeze in a warm place until you need it.

I recommend running the motor in spring to eliminate the fogging oil- that way you don't waste a set of new spark plugs. I also like to wait till spring to replace the impeller because sitting in the housing all winter sets the shape and keeps it from being as effective as it should. The motor and transmission oils should be changed in fall. Add fuel stabilizer, run it to warm it up, change the oils and filter(s), run it again to pull the anti-freeze in and fog the motor. Remove the hull plug(s) and keep them in a plastic bag, attached to the throttle or steering wheel. Clear out any debris from the oil cooler. Remove the speedo lines at the gauges and blow air into them to clear out any water (the ballast tubes at the transom have a tendency to burst if they have water in them). Remove the battery(s) and charge them fully, checking them once a month or keep them on a trickle charger all winter.

In spring, run it to get rid of the fogging oil, do your tune-up (if needed) and put the hull plug(s) back in.

10-05-2006, 01:15 PM
Now this is a part where I am getting confuse. Do you leave the antifreeze in or drain it ? The owner manual saying to leave all plugs and hose disconnect during the storage season. Am I missing some thing here ?


east tx skier
10-05-2006, 01:29 PM
Most people I've seen using antifreeze leave it in until they dewinterize in the spring. It ought to be fine either way though.