Winterizing Your Indmar Monsoon Engine

[hockeyhymore8]

^{This is my first season with my Bu, I have winterized boats several times in the past but never an Inboard. I tried to start the winterization process this past weekend. The first thing I did was ran the boat using a fake a lake with just water to bring the boat to temp. I then ran RV anti-freeze through the engine using fake a lake until exhaust ran dark pink. I watched the winterization video and started pulling hoses after I ran the anti-freeze through the engine. I found areas thoughout the system that would run pretty clear, it seemed to be after the thermostat, I checked the freezing point of the draining water using an glycol tester, the test ratings were about +25 freezing point. So I tried to drain the system again and run anti-freeze through it again using fake a lake. I again checked the liquid by pullng some hoses/block plug and some areas don't seem to get water flow very easily and still had liquid with above zero freezing points. I drained the block plugs and I think I am going to pull the thermostat and just pour antifreeze directly past that to ensure I am not leaving anything in the block. Am I worring to much about getting all the water out? This is the first boat I have ever personal owned so I want to make sure it is done right and I am storing it in Northwest Ohio, so winter temps can sometimes get down to around 0F.}

[tango42]

I would think that a block full of water would take forever to flush sufficiently with antifreeze - and waste a lot in the process. The reason for draining first is so you know that only antifreeze is in there. Also, if the motor is not hot enough to open the thermostat, only the exhaust will fill with antifreeze - then your really in trouble.

I just did mine yesterday - drained everything, then filled it with antifreeze manually because I like the corrosion protection. There are many opinions on winterization and antifreeze, and this is mine.

[MalibuTime]

Antifreeze definitely a personal preference. Seems like a lot of mess to me when empty is just as effective.

I just drain everything and leave it in the (heated, unless power is out and it is 10 degrees while I am on vacation) garage. Make sure to reseal with high temp thread sealer and put those knock sensors (plugs) back in. Those cast iron threads will rust if you don't.

I think this winter I will add the quick disconnects to the heater hoses to speed up that draining process.

[nemalibu]

I would think that a block full of water would take forever to flush sufficiently with antifreeze - and waste a lot in the process. The reason for draining first is so you know that only antifreeze is in there. Also, if the motor is not hot enough to open the thermostat, only the exhaust will fill with antifreeze - then your really in trouble.

I just did mine yesterday - drained everything, then filled it with antifreeze manually because I like the corrosion protection. There are many opinions on winterization and antifreeze, and this is mine.

Before you do the initial draining do you run the engine up to temp to get the thermostat to open?

[tango42]

Before you do the initial draining do you run the engine up to temp to get the thermostat to open?

No, there is not a problem draining with the thermostat closed - everything drains from the bottom and the thermostat still has small bypass holes to allow any water above it to drain.

I use never-seize on the plug threads - it never fails to seal and they come out easy next season. I pull the heater hoses off the motor and run antifreeze thru in one until it comes out red from the other.

[WoodyBC]

First time winterizer, 2001 Sunsetter. 325 Monsoon. I really dont want to screw this up.

I've read all I can find about winterizing and here is my plan. The oil, filter, fuel treatment, fuel filter, are already handled. I'm just nervous about the water freezing in something I failed to drain. I have drained the block, both sides, the exhaust manifolds, and pulled the hoses off the water impeller and drained more out of there so Im comfortable with that.

I have ordered the Flow-Pro valve and will install it as soon as it arrives. I plan to hook it up, put water to the engine, warm it up to operating temperature and then shut it down. Then I'm going to drain the water, hook up the Flow-Pro again and pump in the antifreeze, run the engine (now the thermostat is open right?) and after the antifreeze is spitting out the exhaust, fog the throttle body and shut down the motor.

Have I missed anything? I really want to do this right, the first time....

Thanks everyone.

[davemac]

Woody, do you have a heater or shower? If so, you must tend to them. For heater, I disconnect hoses from block, send some bursts of air down the top hose....water will come out the bottom hose (have it positioned over bilge to prevent a mess). Get a funnel and send some RV antifreeze down the top hose (1/4 gallon should do). Send a couple more burst of air down til you see pink antifreeze coming out bottom hose.

Tip (after winterizing my boat yesterday): I ran the boat on fake-a-lake before draining oil. Just because temp gauge comes up to 160 doesn't mean oil has warmed enough to flow better. Give it more time.

For the record, I store my block dry (no antifreeze) and drain fuel tank as low as possible. I don't care to argue merits with those that choose otherwise...but this has always worked for me.

[WoodyBC]

No heater or shower. I fear missing that "thing" that everyone knows to drain except me and my motor is all jacked up next spring. Does it sound like I'm on the right track?

[WoodyBC]

Ran the boat around the lake got it good and warm, pulled it and changed the oil. Went real smooth.

[scooby]

Take the time and look at all your hoses and the path the water takes through the system. If you have the water out everything is good. For added piece of mind you can always buy the antifreeze and manually blow it through the engine. I do this and then watch it run out the block.

On thing, when you reconnect everything in the spring make sure you take your time and tighten all hoses. Air in the system may trip the engine electronics to a limp mode.

Last thing I do it spray a silicon spray on the engine and hose to help stop any rusting and it keep the engine looking clean.