Overheat Alarm during winterization

[wish2fish]

I was winterizing the boat and the overheat alarm started to sound. I had already run on the hose, changed the oil and outdrive lube. Restarted and made sure the engine was up to temp again (170* F). Disconnected water line and connected to 5 gallon tank of antifreeze. Antifreeze was being drawn into the motor but after about 2 gallons the alarm began to sound. Even though the alarm was sounding the antifreeze was still being drawn into the motor. I was using the quicksliver flush muffs connected to antifreeze tank via 5/8" ID hose.

Does anyone see why the alarm would sound on this set up? Is it possible that the impeller is still working but not not up to par?

 

[mrsrobinson]

Low water flow is my guess

 

[SR Tech]

^correct

motors allready up to temp, and now your starving for cooling. The antifreeze didn't make it to the thermostat before the alarm went off.

Your impeller should be fine. If you let the motor cool a bit and then try it again, you wont get the alarm.

 

[Sublimetime]

Your garden hose is feeding thru the 5/8 hose under greater pressure, while the pink stuff is being fed by gravity to the pump, it couldn't keep up with the heat buildup.

 

[wish2fish]

Sr tech and others.

how can the pump do a better job when the boat is in the water? How do you avoid this problem in the shop?

 

[douglee25]

Sr tech and others.

how can the pump do a better job when the boat is in the water? How do you avoid this problem in the shop?

Due to the added head pressure.

Doug

 

[wish2fish]

doug,
what is head pressure? All the heads I knew in high school didn't know what pressure was!

 

[douglee25]

doug,
what is head pressure? All the heads I knew in high school didn't know what pressure was!

Head pressure is a function of height or depth (depends on the situation at hand), gravity, and density. You would have to draw a free body diagram to see exactly, but there is a greater net height difference from the water inlet on the outdrive to the pump vs. the height difference from the bucket on the swim platform to the pump. The greater the height or depth, the greater the head pressure. Same principal when you dive deeper in water, the greater the pressure exerted on your ear drum.

Doug

 

[wish2fish]

Well, I guess I'm done!

With everything completed I squeezed the boat into the garage which is no easy task! The garage door is 9ft wide....and the beam is 8' 6". I have partially back in with the truck because of the lip from the driveway to garage and then disconnect from vehicle because I have to lower the tounge so the windsheild can get in. Made it with no damage to garage or boat!

 

[Dave S]

Wish

I had the same problem with my 240SD when I would winterize it. Then after watching my dealers Techs winterize other B3s, I saw they reved the engine a bit while feeding in the pink stuff and never got an overheat alarm. That extra speed up of the pump RPMs probably allows the pink stuff to be sucked in a lot faster.

Dave

 

[wish2fish]

great point dave. wish I would have thought of that.

It looked to me that the antifreeze was coming out of the container faster than it was being sucked up. There was quite a bit of air in the tubing that eventually filled with antifreeze during the process.

 

[wish2fish]

Well, all winter/spring has passed and I haven't done anything to check out the impeller situation. I intended to have the mechanic redo the waterpump but I never got him the boat. Will pull the boat out of the garage this week. Any suggestions to determine if the waterpump impeller is still okay? Will running on the hose be good enough check?

I'm going to go ahead and get new impeller or pump. Is the engine serial number enough to get the right parts.