Questions on new engine

Nomo

Cadet
Joined
Mar 25, 2010
Messages
25
I'm a new forum member, but I've been referring to it for evening reading for quite some time. Thanks for all the great info.

Last summer I replaced an '86 Mercruiser 470/Alpha One with a new 4.3tks/Alpha One power package (closed cooling system). It was surplus stock I bought from a going out of business boat factory. Only had 1 chance to do break-in last year before I had to winterize, but everything worked great.

I had to plumb in a through-hull water intake for this engine. I've never used one of these systems before nor have I ever seen one. Sorry if these seem like ridiculous questions.

1. Does my new stern drive still use a water pump impellor, or is it just an empty housing?
2. Does the engine mounted raw water pump need annual maintenance?
3. Is there any way to flush the raw water system with a garden hose? How would it hook up?

Thanks for your input.
 

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,321
Re: Questions on new engine

Welcome aboard Nomo.....

A 4.3 doesn't and shouldn't need a seperate engine mounted pump with a through hull. Can you post your engines serial number and maybe some pictures of the engine and drive (more is better) along with your through hull seacock?
 

CaptainHook

Petty Officer 1st Class
Joined
Mar 18, 2010
Messages
310
Re: Questions on new engine

That motor should use the water pump in your outdrive to provide water to the heat exchanger.

If the work is already done then no, you no longer need an impeller in the outdrive since that water hose would no longer be connected to anything. Is this so???

Yes, raw water pumps need maintenancce and winterizing as well!!!

You can install a hose hook up on the water pick up line going to the raw water pump to run on land and flush.

i currently have a 470 that I want to replace with the same kind of set up. How much did this conversion cost you if you don't mind me asking?????
 

Rocky_Road

Lieutenant Commander
Joined
Oct 8, 2008
Messages
1,798
Re: Questions on new engine

I'm a new forum member, but I've been referring to it for evening reading for quite some time. Thanks for all the great info.

Last summer I replaced an '86 Mercruiser 470/Alpha One with a new 4.3tks/Alpha One power package (closed cooling system). It was surplus stock I bought from a going out of business boat factory. Only had 1 chance to do break-in last year before I had to winterize, but everything worked great.

I had to plumb in a through-hull water intake for this engine. I've never used one of these systems before nor have I ever seen one. Sorry if these seem like ridiculous questions.

1. Does my new stern drive still use a water pump impellor, or is it just an empty housing?
2. Does the engine mounted raw water pump need annual maintenance?
3. Is there any way to flush the raw water system with a garden hose? How would it hook up?

Thanks for your input.

In answer to your second question--most that come here will suggest an annual impeller replacement, for safety's sake. I am not so fastidious, and go longer unless I suspect that something may be going south. I keep a close eye on my gauges, and my first impeller looked great after more than 2 seasons. You will have to decide what makes you comfortable....

Your third question is answered by an inline flushing attachment--one that you can hook a garden hose up to, and the water pressure closes the path going down to the hull pickup:

http://www.foreandaftmarine.com/9-456DP4.htm

Happy boating!
 

Nomo

Cadet
Joined
Mar 25, 2010
Messages
25
Re: Questions on new engine

Jason,
My warranty registration copy lists the following 3 numbers:
Serial# 1A335347 (Is that the engine?)
Drive Serial# 1A263812
Not sure what the third number represents 1A177248.
 

Nomo

Cadet
Joined
Mar 25, 2010
Messages
25
Re: Questions on new engine

Captain Hook,
You are correct...where you would normally see the hose fitting on the transom assembly is replaced with a plate on this model. No hose from the drive assembly to the engine.

As far as cost, I paid less than $3000.00. I thought that was only going to be the engine and then I would have to go shopping for transom assy and outdrive. I was shocked to find waiting for me was a complete power package...even had new power steering system and trim/tilt motor and pump. The installation tec at the plant said they had to empty their parts warehouse and they couldn't return their inventory, so I was the luck one. They were dumping boats, trailers, parts, tools like crazy. He even installed it for me and filled out the warranty info. I couldn't believe it! The only thing I had to do was plumb the through hull, and he gave me detailed drawings and instructions and ordered the parts I would need. Talk about going above and beyond.
 

Nomo

Cadet
Joined
Mar 25, 2010
Messages
25
Re: Questions on new engine

Rocky Road,
Thanks for the link. I think that looks like the ticket.
 

Rocky_Road

Lieutenant Commander
Joined
Oct 8, 2008
Messages
1,798
Re: Questions on new engine

Rocky Road,
Thanks for the link. I think that looks like the ticket.

My pleasure!

Boy...you must have thought that Christmas came early with the deal that you got! Talk about coming up smelling like 'roses'!

Do you also recommend lotto numbers? PM me if you do....

Happy boating!
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
Re: Questions on new engine

I would suggest you install a sea strainer - especially if you boat in an area with sea weeds, etc. Then you can simply remove the cap and put you hose in the strainer. Here's a pic of mine:

DSCF1149.jpg



Also - in regards to your question about the pump in the outdrive. Does yours currently have one? I had a similar set up in the boat pictured above. I had an Alpha outdrive and asked the question of Mercruiser directly. They suggested keeping the pump in the outdrive and letting the water simply splash out of the top - their thinking it is helps cool the outdrive. I ended up simply routing through the transom and back out the back again.
 

Nomo

Cadet
Joined
Mar 25, 2010
Messages
25
Re: Questions on new engine

Fishermark,
Is that just a removable cleanable canister on the strainer?

I don't know if the outdrive has a pump. I guess I'll pull it apart this spring to find out. I'd like to re-check the alignment anyway. It does make sense to have one in there for outdrive cooling.

Rocky Road, I'm the kind of guy who will usually come out guessing wrong with 50/50 odds. But in this case the saying is true, "The sun even shines on a dog's a** once in a while."
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
Re: Questions on new engine

Yes, there is a stainless steel basket inside the unit. The top is made of bronze, with a cap that has an o-ring seal. Nice unit, works good.


Here's a pic of the Groco unit I have on my boat:

GR1408_L.jpg




If you do decide to go that route, or any other flushing system for that matter, you will still need to find out if there is a pump in the outdrive. If there is, you will need to run it on muffs AND put a hose in the strainer. Otherwise you will burn up the impeller in the outdrive if there is one.
 

Nomo

Cadet
Joined
Mar 25, 2010
Messages
25
Re: Questions on new engine

Yah, Fishermark...engine and outdrive would need a seperate water source. Guess my muffs maybe aren't obsolete after all. Thanks.
 

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,321
Re: Questions on new engine

If your boat is big/heavy you do want to keep an eye on your gear lube. There is a water passage in the upper section that does help cool the unit, as the upper is out of the water when the boats on plane.
 

Nomo

Cadet
Joined
Mar 25, 2010
Messages
25
Re: Questions on new engine

Hey fellas,
This spring I'll also need to see if I'm in the right rpm range at WOT. What kind of instrument do you recommend to accurately measure rpms?
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
Re: Questions on new engine

Hey fellas,
This spring I'll also need to see if I'm in the right rpm range at WOT. What kind of instrument do you recommend to accurately measure rpms?

Uhm.... a tach maybe? :confused:
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,090
Re: Questions on new engine

Ayuh,... I can't think of anything other than a tachometer for the job...
 

Nomo

Cadet
Joined
Mar 25, 2010
Messages
25
Re: Questions on new engine

Thanks, I was just curoius about checking the accuracy of my 24 year old tach against something else. The needle seems kind of jumpy when there is no apparent change in the engine rpm.
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
Re: Questions on new engine

You can try a new tach - or check your current connections.
 

Rocky_Road

Lieutenant Commander
Joined
Oct 8, 2008
Messages
1,798
Re: Questions on new engine

Thanks, I was just curoius about checking the accuracy of my 24 year old tach against something else. The needle seems kind of jumpy when there is no apparent change in the engine rpm.

My MATCO tach/timing light (MTL4186) is what I use to set my engine to specs, and to check RPM's. It is the inductive style and easy to use on the water. I needed to use this because although my helm tach is working, it has a tendency to 'stick' and not show the true range. You would be wise to follow your own suggestion, and check yours with something more precise....

Some people use what they call the Tiny Tach...which I think will double as a hour counter. This will normally sit somewhere in the engine bay, and can be installed in just a few minutes. Check out about the hour meter part, though...I might have this wrong!

Happy boating!
 

Nomo

Cadet
Joined
Mar 25, 2010
Messages
25
Re: Questions on new engine

Thanks again for your direction Rocky Road. I'll see if anyone around here has a timing light like that.
 
Top