Clogged Impellor and Winterization

[Begester]

Last week I took my boat out of the water and the ramp was quite shallow due to low lake level and I ran through a good bit of sand/mud, to the point that it killed the engine a couple times when I was trying to get it on the trailer.

Last night, while running the engine on the earmuffs, I noticed that there was no water spraying out of the typical spots (just at the transom and out the center of the prop) which tells me that there is mud/sand in the impellor and my engine is not getting any water. To further exascerbate this, I pulled the freeze plugs and very little water came out and what did come out was dirty. I am confident that this is dirt/sand and not oil or anything else, which leads me to believe that I have a clogged impellor…right? The engine never overheated and upon visual inspection nothing smelled hot, no oil or coolant appears to be in places it shouldn’t, and everything sounds fine.

I usually replace the impellor at the BEGINNING of every other season and have never had an issue before but I’m wondering if there is a way to “unclog” the system so I can winterize and ensure that no water is trapped in the system over the winter. My logic here is that if I replace the impellor in the spring, I will have a “new” part that didn’t have to sit in the elements all winter…does that logic pass muster? I live in Washington State so it can get down to 20 degrees or so in the winter.

If so, would anything be solved if I put the boat in the water to try and unclog it? My thought here is that the added pressure on the water inlets at the outdrive could free things up and get me through the winter. Is this valid logic?

I am conscious about the importance of this part and system and want to make sure I give it the attention it deserves…if I mess this up its going to cost me thousands!

Engine is 5.7L w/ Alpha 1 outdrive and freshwater exchanger. Any insight or advice is greatly appreciated.

 

[thumpar]

The impeller is probably missing fins. With the sand that it sucked up you will probably want to replace the housing along with the impeller. I am not sure where you are in WA but here in Spokane we are already getting down to single digits so you better get it winterized fast.

 

[81 Checkmate]

Here is what i would do in your situation. Just me!

Take off inlet hose from drive on t-stat...flush out motor with garden hose, then pull all drains and big hose off circ pump.

Back flush with garden hose to the drive till water comes out inlet holes on drive.......then lower drive unit all the way down to drain. pull hose off P.S. cooler and drain.


Depending how you winterize........add pink stuff if you want to or just leave as is untill next spring.

 

[thumpar]

The way the pump is designed you won't be able to backflush the actual pump unless the impeller is tore up. Take it apart and fix it. You can take the drive off and put a hose in the inlet on the bellhousing to feed water to the engine if you need to run it for winterizing.

 

[Bondo]

Here is what i would do in your situation. Just me!

Take off inlet hose from drive on t-stat...flush out motor with garden hose, then pull all drains and big hose off circ pump.

Back flush with garden hose to the drive till water comes out inlet holes on drive.......then lower drive unit all the way down to drain. pull hose off P.S. cooler and drain.


Depending how you winterize........add pink stuff if you want to or just leave as is untill next spring.

Ayuh,.... I agree, Flush, 'n drain the motor 1st,....

Then I'd pull the drive off, 'n store it warm, til ya get a chance to tear it down,....
You could then back-flush the drive to t-stat line,....

 

[Begester]

Thanks everyone for all the replies. I may have done this a roundabout way but I pulled the hose on the inside of the transom which was connected to the "water" part of my freshwater exchanger system...it was the easiest to get off and was a low spot in the system. I flushed the system "upward" of this and everything looks good. Then I tried to hook up the muffs again and started the engine for a few seconds with the hose removed...thinking that if the problem was somewhere in the engine, I'd have water shooting from the inlet inside the transom, which comes in from the outdrive. Nothing...not a drop came in. Does this isolate the issue to the outdrive?

Also, do the replies above assume no freshwater exchanger? Everything that goes to/from the thermostat appears to be antifreeze lines if I'm connecting the dots correctly.

Thanks again for all the help and replies. I'm pretty mechanically inclined but by no means an expert in this area.

 

[81 Checkmate]

Thanks everyone for all the replies. I may have done this a roundabout way but I pulled the hose on the inside of the transom which was connected to the "water" part of my freshwater exchanger system...it was the easiest to get off and was a low spot in the system. I flushed the system "upward" of this and everything looks good. Then I tried to hook up the muffs again and started the engine for a few seconds with the hose removed...thinking that if the problem was somewhere in the engine, I'd have water shooting from the inlet inside the transom, which comes in from the outdrive. Nothing...not a drop came in. Does this isolate the issue to the outdrive?

Also, do the replies above assume no freshwater exchanger? Everything that goes to/from the thermostat appears to be antifreeze lines if I'm connecting the dots correctly.

Thanks again for all the help and replies. I'm pretty mechanically inclined but by no means an expert in this area.

Not sure if you are talking about the same thing as we are. Do you have a Closed cooling system on the engine, then fresh water to your exhaust mainifolds?

Post up a pic of your motor or better yet post the serial number on the engine and the guys can tell you what you have.

 

[Begester]

Thanks for all the replies. Attached is a photo of my engine.

 

[Starcraft5834]

"to the point that it killed the engine a couple times when I was trying to get it on the trailer."

meaning using engine thrust to push the boat on the trailer? I've seen this done.. I personally would not do that, to many bad things can happen, like sucking dirt and sand and such into the drive... I understand, it is what it is.. just a suggestion not to use the motor to drive your boat on the trailer.. if you did not use your engine to load your boat,, my apologies... that's all I'd offer as to perhaps avoid doing that in the future....

 

[Begester]

Better file size.

@Imperial - I was referring to the low spots at the marina near the boat ramp while parking at the dock. I agree that the "manual" way is the better way to get the boat on the trailer for the reasons you stated above!

 

[Starcraft5834]

10-4........understood

 

[Lou C]

You've got closed cooling which is a good thing, your main concern is the exhaust manifolds if they are not on the closed cooling side, and the heat exchanger. The way you can tell if they are closed cooled, there will be a hose going to the manifold and a separate hose going to the riser. If you have this set up you don't have to drain the manifold but you do have to drain the riser as they are still raw water cooled. If there is only one hose going to the manifold, then they are raw water cooled and have to be drained. The other thing is the raw water side of the heat exchanger and hoses leading to and from it. That all has to be drained. The engine block is full of AF and you don't have to worry about....
If you sucked up sand and mud your impeller is probably worn, the sand alone will put grooves in the wear plate and it won't pump right. Just get the raw water side of your closed cooling drained and the manifolds/risers if they are not on the closed system.

 

[achris]

.... I pulled the freeze plugs and very little water came out and what did come out was dirty....Engine is 5.7L w/ Alpha 1 outdrive and freshwater exchanger.

Wow... So many answered, yet you all missed this ^... If you pulled a core plug from an engine with closed cooling, then all the cooling water from the heat exchanger should have ended up in the bilge! Second question... Why are you pulling core plugs out? And how are you putting them back?

meaning using engine thrust to push the boat on the trailer? I've seen this done.. I personally would not do that, to many bad things can happen, like sucking dirt and sand and such into the drive... I understand, it is what it is.. just a suggestion not to use the motor to drive your boat on the trailer..

Before I had my 'drop axle' trailer, this was the only method I used to load. It's quick, it's easy and it's safe... Can't do it now , the keel rollers on the current trailer put the bottom of the drive on the ramp if I try... As for it being 'bad', nope, perfectly acceptable... Just go to South Africa, it's the only way they load, all of them, every time...

You've got closed cooling which is a good thing, your main concern is the exhaust manifolds if they are not on the closed cooling side, and the heat exchanger. ....

Look at the photo... That's a Merc genuine heat exchanger. Merc genuine kits for SBC and V6s are full closed system....

My main concern is this pulling of a core plug etc.... Needs a lot more explanation...

Chris.........

 

[Begester]

Thanks everyone for the help and the valuable insight!

@achris - I probably should have called them "drain" plugs. I'm referring to the plastic screw off nuts that are removed to drain water from the risers. I typically remove these every season as part of winterization and put them back on in the spring

 

[achris]

Thanks everyone for the help and the valuable insight!

@achris - I probably should have called them "drain" plugs. I'm referring to the plastic screw off nuts that are removed to drain water from the risers. I typically remove these every season as part of winterization and put them back on in the spring

OK.. not the engine block core plugs, good... I guess that's just about the entire winterising process for you, remove drain plugs from the elbows... The odd oil change and you're done...