Burned up water pump/impeller?

[litespeed999]

I have a 93 Sea Ray 240 Overnighter with 7.4 Merc with Bravo One drive. I was trying to winterize the boat engine myself and had problems getting the antifreeze to go into the drive, and I may have ran the motor too long without water. The motor started to overheat, so I shut it down and let it cool. Tried to hook up the muffs with just water to warm it up again and no water would come out of the drive/exhaust. I just shut it down before I did any more damage.

So what happens when you run a motor a bit too long without water? I believe you burn up your impeller(s) and water pump? Is there only one impeller and water pump or two? With winter coming quick here in MI, I still need to winterize the engine and I won't be able to do that without the impellers sucking in liquids.

I just want to understand what happened so I can talk to a mechanic with some knowledge.

TIA

 

[Lazy Daze]

How much damage is tough to say... not being there, and all. But likely the impeller (raw water pump) is shot. Depending on how long it ran overheating, determines the rest of the damage. (1) raw water pump and (1) circulating pump (like a car). If the impeller vanes broke up, you need to find the pieces.

Forget about what youtube says. Why do you think you need to suck in liquids? Why not just drain and fill? It's really quite easy and only takes a few minutes. Run/fog engine... drain everything... then backfill through the hoses at the t-stat housing. Done. Forget about what youtube says. Wait... did I say that, already?

 

[litespeed999]

I've never winterized my own engine before, but after the terrible job my marina mechanics did last year, I wanted to do it myself. I'm not much of a mechanic and the videos on youtube didnt seem to apply to my boat. I have a buddy who has a boat like mine and he used a gravity feed container that hooks to your muffs and that how the antifreeze pushes through the system. It worked for him for three years and that sounded like the easiest way for me.

I've stared at my engine for hours trying to figure out how to drain it or which hose to back fill or where the thermostat is located, but I'm just guessing. I'm sure if someone came over and we did it together I would be able to understand, but I already made a mistake of how I thought this would work and I dont want to damage the engine.

I'm sure I want to have the impeller fixed before I winterize, so I need to get going before the freeze sets in by next week.

 

[Lazy Daze]

If you use the gravity/bucket method, you still need to drain the engine first. And, ideally, also remove the t-stat. That's the ONLY way to guarantee that that method will be 100% successful. Otherwise, you will have "some" mix of water/antifreeze through the engine. Just because your buddy was successful before, doesn't mean he will always be. I see a couple cracked blocks/manifolds EVERY spring from people doing it that way. It's almost like clockwork.

 

[Express 390]

I have a 93 Sea Ray 240 Overnighter with 7.4 Merc with Bravo One drive. I was trying to winterize the boat engine myself and had problems getting the antifreeze to go into the drive, and I may have ran the motor too long without water. The motor started to overheat, so I shut it down and let it cool. Tried to hook up the muffs with just water to warm it up again and no water would come out of the drive/exhaust. I just shut it down before I did any more damage.

So what happens when you run a motor a bit too long without water? I believe you burn up your impeller(s) and water pump? Is there only one impeller and water pump or two? With winter coming quick here in MI, I still need to winterize the engine and I won't be able to do that without the impellers sucking in liquids.

I just want to understand what happened so I can talk to a mechanic with some knowledge.

TIA

First sorry about the problem, If my memory serves me right you are salt water cooled and that outdrive does not contain a water pump you have a raw water pump that's on the motor and sucks up through the outdrive. If you used a garden hose to a set of ears, it may have collapsed the hose . The key is to use a small pony pump to ears and from the antifreeze. But first you need to replace the impeller in the raw water pump ! "Just my opinion " good luck