Mercrusier 5.0L MPI Alpa w/ Single Port Drain

I'm sure this will be a story of the week. I'm actually embarrassed to write about the events that took place yesterday while winterizing my boat this year. My boat is a 2004 Sea Ray Sundeck 220 SD and I've been winterizing it for years without an issue. However, this year was a disaster. My mind was definitely elsewhere that day and the chatty guy at the marina did help either. Anyway.....

1st.... During the winterizing process the block was drained using the single port drain system and muffs were connected to flush the salt water from the engine. Unfortunately the engine ran for approximately 1 minute (no longer) with the Single port drain system (blue valve) and the blue plug in the thermostat housing not installed. Water began to exit the bottom drain and out through the transoms drain plug. The engine did not overheat but did reach and engine temperature of approximately 180 degrees. Engine was shut down.

Next issue. After closing all the drains, a second attempt was made to flush the engine using the muffs. Apparently the muffs shifted off part of the intakes on the stern drive and the engine temperature rose while I was checking the muffs from the swim platform and the alarm went off. The engine was immediately shut down.

After recruiting a second pair of eyes I re-secured the muffs and flushed the salt water from the engine without incident. The engine ran for approximately 10 minutes and all gauges were reading normal.

I understand that running the overheating the engine even for short periods of time can cause damage but how concerned should I be????

Without a doubt I'm going to have the impeller in my stern drive changed, but is there any other things I should have my mechanic check for to make sure the engine & stern drive were not damaged so I can feel comfortable when I put the boat back in the water next season.

Thanks for your anticipated for everyone's help and advice. I fully expect some smart comments which I deserve, so be gentle I feel bad enough!!!!

Ceeg

You did no damage. No worries.

The only issue I have found with this system is that you can never be certain if the block is draining.
I have found the brass fitting in the block completely closed off with corrosion.
I remove the hose to verify that the block drain is not plugged and have eliminated this system from a few customers boals already. On average about 3 1/2 gallons of water should drain from the single point drain plug.
Manually removing a brass block plug and probing the opening to make sure its open is a better option.Some motors are easier to work on draining , some are a real struggle to even get to the brass plugs
Guess wrong and your replacing a block and manifolds

Thanks Dockside Marine Services. The favorable responses are definitely putting my mind at ease. I'm actually located in Toms River, NJ and will keep your company in mind not if, but when my boat needs repairs.

Thanks again.

What is that particular hose connected to?

ceeg52 said:

What is that particular hose connected to?

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That is the lower block drain hose. There is one on each side of the engine block. Always pull these hoses and push a wire through the brass barb to make sure the block is full drained. So not rely on the Single Point Drain to empty the Engine block.

Ceeg, fist off, I fully agree with Chris.
ALWAYS probe the open ports with a small tool of sorts as to ensure that no rust scale is blocking the seawater from completely draning!


And I'll add........ get rid of the "single point" drain system!
These should NOT be used on any RWC Marine Engine..... period!

(several years ago, a man brought his boat to me for an engine replacement (later model Volvo Penta/SX drive).
His cylinder block and both cylinder heads were freeze damaged from having an alleged Marine Shop Mechanic winterize the system.
This engine was one of those that was equipped with the "single point drain system"!
Rust scale had prevented the seawater from draining.
Winter came and gone. Several years had passed since this, and the shop had long since closed the doors.
This ended up costing him a new SBC Engine plus the installation labor...... all because some knucklehead did not see the risks with the Single Point drain system! )


As for installing new and individual petcocks, steer clear of any whereby the stop cannot be removed.
We want a removable stop so that the open port can be easily probed as to remove any rust scale that may prevent seawater from draining completely!!!

This is a true Marine Petcock.
Note that the stop is completely removable, leaving us with an opening that can be probed easily
(you can order these right here through ME.com)

ceeg52 said:

1st.... During the winterizing process the block was drained using the single port drain system and muffs were connected to flush the salt water from the engine. Unfortunately the engine ran for approximately 1 minute (no longer) with the Single port drain system (blue valve) and the blue plug in the thermostat housing not installed. Water began to exit the bottom drain and out through the transoms drain plug. The engine did not overheat but did reach and engine temperature of approximately 180 degrees. Engine was shut down.
180* should not be a threat!

Next issue. After closing all the drains, a second attempt was made to flush the engine using the muffs. Apparently the muffs shifted off part of the intakes on the stern drive and the engine temperature rose while I was checking the muffs from the swim platform and the alarm went off. The engine was immediately shut down.

After recruiting a second pair of eyes I re-secured the muffs and flushed the salt water from the engine without incident. The engine ran for approximately 10 minutes and all gauges were reading normal.
I would suggest that you remove the seawater pump's impeller and inspect it and the pump body.
Why...... because when the water muffs shifted, you created what was essentially a "dry start" for a longer duration than what an impeller will typically sustain!

I understand that running the overheating the engine even for short periods of time can cause damage but how concerned should I be????
See above!

Without a doubt I'm going to have the impeller in my stern drive changed, but is there any other things I should have my mechanic check for to make sure the engine & stern drive were not damaged so I can feel comfortable when I put the boat back in the water next season.
Yes..... along with the over-heat caused by the lack of coolant (i.e., garden hose water), your exhaust components recieved "dry" exhaust gasses for the duration.
This may have blistered the I.D. of the rubber couplers, damaged the back-flow prevention flappers and/or the exhaust bellows.


Thanks for your anticipated for everyone's help and advice.
I fully expect some smart comments which I deserve, so be gentle I feel bad enough!!!!

Ceeg, we are often our own worst critic, and are often the most hard on ourselves!
We will be gentle!

Click to expand...

Thanks

BTW..... I believe that it's single "point" .... not single port!

And if your wondering what is in the expensive black and grey plastic ball that has the blue drain plug that always cracks the housing
N O T H I N G

Make your own and drill and tap for a brass drain plug

Dont have a pic but I drilled and tapped the T fitting on the bottom for a 1/8 pipe plug to drain the water from the hoses

Thanks for the advice Rick. I won't be replacing the impeller until the spring.

And... if you have the cute blue plastic drain "thumbscrew" plug on your engine... remove it. I once slipped and fell ( at dockside , engine off) and my foot clipped that fitting and sheared it off... dumped a gallon of antifreeze ( I have a "FWC" engine) in the bilge. I replaced that fitting with a brass pipe plug of the correct size. Not as easy to see and needs a .tool to remove, but... won't break off! OR... replace it with the drain per RICARDO in post #8 if you are raw water cooled and drain engine seasonally..

Also removed one of these contraptions , plumbed into the block drains and at the top of the manifold hoses at the T housing.They used a T fitting to install the lines. There was a hose connection on the transom for flushing the motor and manifolds but look.......................................



No flushing water in and no block water out.

Bt Doctur...... I agree..... that device is as silly as is the helm located Manual/OFF/Auto bilge pump switch!

What were these manufactures thinking????

For bilge pump installation I have found the most reliable method is to run a pos and neg wire direct to the battery. I avoid the neg return found in the bilge area

Agreed! Too important to take a chance on.

Jeff