Very confused about impeller location....

[CTboater78]

Hi Everyone....This is my first post here. I did about 2 hours worth of research before posting this but I couldn't find anything that really answered my question. If I missed something, I apologize for this new post. I have a 2006 Sea Ray 195 Sport with the Mercruiser 4.3MPI seawater-cooled engine. Both the Mercury manual and the serial number indicate that this is an Alpha engine. Everything I've read and every video that I've watched seems to suggest that the impeller is located in the outdrive and requires removal of the lower half of the unit. I did, though, find one reply on this site that read, "I think some Alpha's have belt driven sea water pumps". I realized I was really confused when I looked up the price of the impeller using my engine's serial number on mercuryparts-direct.com. On their microfiche, it shows the impeller behind the sea pump pulley underneath the impeller housing (I've attached a pic of the microfiche), not in the outdrive.

I really don't want to drop the lower half of the drive if I don't have to so I'm hoping that someone can clarify this for me based on their own experience. I skimmed every page in the Mercruiser manual as well and nothing addresses the impeller location. Can I possibly have a Mercruiser 4.3MPI Alpha drive engine with the impeller located inside of the seawater pump in the engine compartment and NOT in the lower half of the outdrive? Any help is greatly appreciated! Thanks.


Gary

 

[thumpar]

Re: Very confused about impeller location....

The easiest way to tell is to look and see if you have a belt driven seawater pump or not.

 

[Don S]

Re: Very confused about impeller location....

If you have an Alpha drive and a raw water cooled engine, the impeller (raw water pump) is in the outdrive. If you have a Bravo drive, it is engine mounted.

 

[ktbarrentine]

Re: Very confused about impeller location....

I am confused at what manual you are using. My Mercruiser outdrive manual (OEM) clearly shows the impeller and gives crystal clear instructions on how to replace it. Let's see if we can help you get to the right place in your "outdrive" (not engine) manual.

 

[Fun Times]

Re: Very confused about impeller location....

Do you know for sure if you have a bravo or alpha drive on the back of the boat?

Posting your serial numbers would help determine what engine package you would have had when new.

Posting a photo of the front of the engine along with the belts may help us let you know what you have as well.

 

[MarkSee]

Re: Very confused about impeller location....

I did, though, find one reply on this site that read, "I think some Alpha's have belt driven sea water pumps". Can I possibly have a Mercruiser 4.3MPI Alpha drive engine with the impeller located inside of the seawater pump in the engine compartment and NOT in the lower half of the outdrive? Any help is greatly appreciated! Thanks.

Well, according to some documentation on the well known Sterdrives.com site (see link about 1/3 of the way down):
Mercruiser Water pump kits. Waterpump kits. Water pump rebuild kits. Impellars.

Some Alpha Ones might not be using the pump in the drive but instead
have elected to use a belt driven sea water pump.
This is usually the case with closed cooling system equipped engines.
Belt Driven Raw Water Pumps are also used on engines with Bravo drives.

So yes, unless that is wrong information, it is possible you very well could have a Bravo style sea water pump with an alpha drive.

I remember posts about that with V8 Merc engines, just can't remember if one of those was dealing with a 4.3mpi.

As was recommended, posting photos of the engine compartment, drive and serial numbers would help.

Mark

 

[CTboater78]

Re: Very confused about impeller location....

Do you know for sure if you have a bravo or alpha drive on the back of the boat?

Posting your serial numbers would help determine what engine package you would have had when new.

Posting a photo of the front of the engine along with the belts may help us let you know what you have as well.

Unfortunately the boat is still shrink-wrapped. I'm hoping to wait another week or two to remove it to make sure that winter is over here in CT. Attached is the serial number and other engine information and also a screen shot from my Merc manual. Apparently the engine either comes with a sea water pulley driven pump or not. I'm going to have to take a look once I can get back into the engine compartment. Is it safe to assume that if my pulley system is like the first diagram, then my impeller is in the engine compartment and not in the outdrive?

 

[achris]

Re: Very confused about impeller location....

Engine mounted seawater pumps are always an option on Alpha drives. The engine mounted pump can flow about twice that of the drive mounted pump and are recommended to be installed on engines in boats used in warmer water.

In short... Yes you could have an engine mounted pump, but in CT, I seriously doubt it. A photo of the front of the engine will clear it up one way or the other. As you have the diagram from the manual you should be able to work it out yourself without too much trouble.

A word of caution. You have a 2006 4.3MPI, same as mine. There is about a 1 in 20 chance you have a faulty oil pan. To check, have a feel of the front of the oil pan directly under the crankshaft pulley. If your hand comes up oily, have a read of THIS and THIS ...

Chris..........

 

[agallant80]

Re: Very confused about impeller location....

Just don't confuse the pump on the front of your motor as the raw water pump, every block has a pump mounted in the middle of it just like a car. If I remember correct my block mounted pump connects to the raw water pump that is on the lower left side of the block, but mine is a 5.0 so I don't know if the pump on a 4.3 is in the lower left or not. Chances are that you have to change the impeller on the outdrive. It will take about an hour your first time. There are many videos on yourube showing how to do it. If its your first time take photos so you can verify how things were before you put them back togeather.

 

[Bondo]

Re: Very confused about impeller location....

Just don't confuse the pump on the front of your motor as the raw water pump, every block has a pump mounted in the middle of it just like a car. If I remember correct my block mounted pump connects to the raw water pump that is on the lower left side of the block, but mine is a 5.0 so I don't know if the pump on a 4.3 is in the lower left or not. Chances are that you have to change the impeller on the outdrive. It will take about an hour your first time. There are many videos on yourube showing how to do it. If its your first time take photos so you can verify how things were before you put them back togeather.

Ayuh,.... Turn around, yer facin' the Wrong way....

That's Why boats have a port-side, 'n starboard-side...

 

[Don S]

Re: Very confused about impeller location....

According to Mercruiser, you have an Alpha Drive on your boat, What it doesn't say is if you have factory closed cooling or not.
If raw water cooled, they came standard with the raw water pump in the outdrive. Someone may have changed it to an engine mounted pump, but highly doubtful.
If you have a full OEM closed cooling system installed, then it will have the engine mounted pump, along with the pump in the drive.
If you have an after market closed cooling system, you may or may not have the engine mounted pump,

What this amounts to, is that all we can do is guess at what you have. The only way you will know if you have an engine pump or not is to get in there and look.

Since the Merc site says nothing about it being close cooled, I am going to assume for a minute you have the standard Alpha cooling system with the pump in the drive. The drive should be removed yearly for maintenance and inspection, and if you are doing your own maintenance, then you really need to learn how to pull the drive to do these jobs,

Spend some time reading HERE the impeller is not that big a job, and is just part of preventive maintenance you need to learn to do your own work.

View attachment A1G2 R&R.pdf View attachment A1G2 Impeller Replace.pdf

 

[CTboater78]

Re: Very confused about impeller location....

Thank you guys. I was able to get in and snap a picture of the front of the engine. I hope it's a clear enough photo. Please let me know your thoughts....

 

[Don S]

Re: Very confused about impeller location....

No raw water pump in that picture.

If nothing else, just count the pulleys and look at the belt angles in your manual.

 

[agallant80]

Re: Very confused about impeller location....

No raw water pump in that picture.

+1

My 2011 4.3MPI with A1 had no raw water pump. You don't have one.

 

[Bondo]

Re: Very confused about impeller location....

Hi Everyone....This is my first post here. I did about 2 hours worth of research before posting this but I couldn't find anything that really answered my question. If I missed something, I apologize for this new post. I have a 2006 Sea Ray 195 Sport with the Mercruiser 4.3MPI seawater-cooled engine. Both the Mercury manual and the serial number indicate that this is an Alpha engine. Everything I've read and every video that I've watched seems to suggest that the impeller is located in the outdrive and requires removal of the lower half of the unit. I did, though, find one reply on this site that read, "I think some Alpha's have belt driven sea water pumps". I realized I was really confused when I looked up the price of the impeller using my engine's serial number on mercuryparts-direct.com. On their microfiche, it shows the impeller behind the sea pump pulley underneath the impeller housing (I've attached a pic of the microfiche), not in the outdrive.

I really don't want to drop the lower half of the drive if I don't have to so I'm hoping that someone can clarify this for me based on their own experience. I skimmed every page in the Mercruiser manual as well and nothing addresses the impeller location. Can I possibly have a Mercruiser 4.3MPI Alpha drive engine with the impeller located inside of the seawater pump in the engine compartment and NOT in the lower half of the outdrive? Any help is greatly appreciated! Thanks.


Gary

Ayuh,.... Welcome Aboard,.... Based on yer pictures, Yer impeller pump is on the top of the lower unit,...

The lower unit will need to come off the upper drive...

Both should come off Anyways, just for service, 'n greasin'....

Get the "Kit" for the Alpha 1, Gen.II, 'n replace the whole thing, especially if ya don't know the history of it....

 

[CTboater78]

Re: Very confused about impeller location....

Thank you all very much for the clarification. I called my local parts dealer and Merc dealer/Service Shop and they quoted my a price for parts and labor of $175.00. Seems like a no-brainer for me since I don't feel like messing with the drive unit. Off to the shop it goes.

I'm still confused, though, why the microfiche for my engine's serial number shows the impeller in the housing attached to an engine pulley. Maybe the picture is mistakenly of a Bravo engine.....who knows.

Thanks again!

 

[Don S]

Re: Very confused about impeller location....

Thank you all very much for the clarification. I called my local parts dealer and Merc dealer/Service Shop and they quoted my a price for parts and labor of $175.00. Seems like a no-brainer for me since I don't feel like messing with the drive unit. Off to the shop it goes.

I'm still confused, though, why the microfiche for my engine's serial number shows the impeller in the housing attached to an engine pulley. Maybe the picture is mistakenly of a Bravo engine.....who knows.

Thanks again!

Because the fiche for your engine shows only engine, and for both Alpha and Bravo engines. But the Alpha pumps are only shown in the drive fiche since it's not part of the engine.

I also edited your signature so we will know exactly what you have in the future. Makes things a lot easier.

 

[abrx7]

Re: Very confused about impeller location....

Where in CT are you located?

 

[CTboater78]

Re: Very confused about impeller location....

I'm in East Haven.