Stern Drive Conversion
 

I have inherited a 25' MirroCruiser with a 305 and a pre-Alpha Stern Drive
(the one with loop on the top bearing cover).
I have never had this in the water yet.
I have never owned a boat before but I am pretty tech savy.
I needed to repair a few things including:
- the motor (new pistons and valves and I converted it to an electric fuel
pump).
- rewired the charging and added an additional battery with optional solar
charging.
so I took it out and while doing that was surprised to see "REDONE" stamped
on the side of the STERN DRIVE. There was an "O" ring when I took the drive
off the transom gimbal but I see no rubber hose connecting through to the
closed cooling system - It appears to blanked off at the transom end.
There is a pipe in through the hull with a valve and that connects via a hose
to a seawater pump fitted to the engine..
My assumption is that the pre-Alpha drive has been converted somehow.....!!!!!

Stern Drive Conversion
 

Converted to what?

Alpha's still have a built in raw water pump. Both alphas and pre-alphas
can be used with out the built in raw water pump if a suitable pump is
driven by the engine that uses a thru-hull pickup. What you have is not
unheard of.

"Bennie" u31788@uwe wrote in message news:6ddb9fae75174@uwe...
I have inherited a 25' MirroCruiser with a 305 and a pre-Alpha Stern Drive
(the one with loop on the top bearing cover).
I have never had this in the water yet.
I have never owned a boat before but I am pretty tech savy.
I needed to repair a few things including:
- the motor (new pistons and valves and I converted it to an electric fuel
pump).
- rewired the charging and added an additional battery with optional solar
charging.
so I took it out and while doing that was surprised to see "REDONE"
stamped
on the side of the STERN DRIVE. There was an "O" ring when I took the
drive
off the transom gimbal but I see no rubber hose connecting through to the
closed cooling system - It appears to blanked off at the transom end.
There is a pipe in through the hull with a valve and that connects via a
hose
to a seawater pump fitted to the engine..
My assumption is that the pre-Alpha drive has been converted
somehow.....!!!!!

Stern Drive Conversion
 

"Bennie" u31788@uwe wrote in message news:6ddb9fae75174@uwe...
I have inherited a 25' MirroCruiser with a 305 and a pre-Alpha Stern Drive
(the one with loop on the top bearing cover).
I have never had this in the water yet.
I have never owned a boat before but I am pretty tech savy.
I needed to repair a few things including:
- the motor (new pistons and valves and I converted it to an electric fuel
pump).


How did you power the electric fuel pump? In the event that you didn't ....
consider providing it's power in a manner that the power is removed if the
engine is not running, even though the ignition may be "on". Often, this is
accomplished by powering it through an oil pressure switch.

Eisboch

Stern Drive Conversion
 

I don't know......It is stamped redone on the outside of the stern drive. Is
it OK just to run the Sterndrive without pipes hooked up since the water
route through the Transom goes to a blank off plate? I was worried about
the stern-drive it's self needing cooled.... The boat definitely has a
through hull raw water pickup that flows through the heat exchanger and out
via the exhaust.
Remember I am OK with anything mechanical (engines, gearboxes etc) but I am
unfamiliar with the needs of sterndrives....

James wrote:
Converted to what?

Alpha's still have a built in raw water pump. Both alphas and pre-alphas
can be used with out the built in raw water pump if a suitable pump is
driven by the engine that uses a thru-hull pickup. What you have is not
unheard of.

I have inherited a 25' MirroCruiser with a 305 and a pre-Alpha Stern Drive
(the one with loop on the top bearing cover).
[quoted text clipped - 16 lines]
My assumption is that the pre-Alpha drive has been converted
somehow.....!!!!!

Stern Drive Conversion
 

It is on the same circuit as the coil...When ign switch is off - no fuel....

Eisboch wrote:
I have inherited a 25' MirroCruiser with a 305 and a pre-Alpha Stern Drive
(the one with loop on the top bearing cover).
[quoted text clipped - 3 lines]
- the motor (new pistons and valves and I converted it to an electric fuel
pump).

How did you power the electric fuel pump? In the event that you didn't ....
consider providing it's power in a manner that the power is removed if the
engine is not running, even though the ignition may be "on". Often, this is
accomplished by powering it through an oil pressure switch.

Eisboch

Stern Drive Conversion
 

Sorry for being a bit slow but I thought there was a potential problem if the
RAW water pump on the Stern Drive was just ignored....
Hopefully I can learn this stuff quickly.

Bennie wrote:
I don't know......It is stamped redone on the outside of the stern drive. Is
it OK just to run the Sterndrive without pipes hooked up since the water
route through the Transom goes to a blank off plate? I was worried about
the stern-drive it's self needing cooled.... The boat definitely has a
through hull raw water pickup that flows through the heat exchanger and out
via the exhaust.
Remember I am OK with anything mechanical (engines, gearboxes etc) but I am
unfamiliar with the needs of sterndrives....

Converted to what?

[quoted text clipped - 8 lines]
My assumption is that the pre-Alpha drive has been converted
somehow.....!!!!!

Stern Drive Conversion
 

"Bennie" u31788@uwe wrote in message news:6ddc5da40cf71@uwe...

It is on the same circuit as the coil...When ign switch is off - no
fuel....

Eisboch wrote:

How did you power the electric fuel pump? In the event that you didn't
....
consider providing it's power in a manner that the power is removed if the
engine is not running, even though the ignition may be "on". Often, this
is
accomplished by powering it through an oil pressure switch.


I suspected that might have been the case when you mentioned that you were
new to boats.
I've been advised by someone far more knowledgeable than I that it should
only be powered
if the engine is running .... via oil switch or other sensor ... and not
powered from the
ignition switch only. Unlike a car or truck, on a boat you don't want the
potential of the fuel
pump pouring fuel on a fire.

If carbureted, you also want the bowl overflow to be plumbed back to the
fuel supply line before the pump and not simply dumped into the bilge like
an automotive carb would do.

Just stuff to think about.

Eisboch

Stern Drive Conversion
 

Bennie wrote:

It is on the same circuit as the coil...When ign switch is off - no fuel....


You'd better get that fixed pretty quick. It wouldn't pass a CG
inspection as it is. Your insurance won't pay for the ensuing fire
damage either(I've denied claims for fires from faulty owner repairs or
mods - many boat policies specifically exclude coverage).

Rob


Eisboch wrote:

I have inherited a 25' MirroCruiser with a 305 and a pre-Alpha Stern Drive
(the one with loop on the top bearing cover).

[quoted text clipped - 3 lines]

- the motor (new pistons and valves and I converted it to an electric fuel
pump).

How did you power the electric fuel pump? In the event that you didn't ....
consider providing it's power in a manner that the power is removed if the
engine is not running, even though the ignition may be "on". Often, this is
accomplished by powering it through an oil pressure switch.

Eisboch

Stern Drive Conversion
 

When ign switch is off - no fuel....

No good! There should only be fuel when the engine is cranking (to start),
or there is oil pressure (engine running). The latter could save your engine
as well. If the oil pressure drops for any reason, the fuel pump will cut
out, and the engine will stop before you melt the block. If the ign switch
is simply on, and the engine isn't running, the fuel pump should NOT be
moving fuel.

--Mike

"Bennie" u31788@uwe wrote in message news:6ddc5da40cf71@uwe...
It is on the same circuit as the coil...When ign switch is off - no
fuel....

Eisboch wrote:
I have inherited a 25' MirroCruiser with a 305 and a pre-Alpha Stern
Drive
(the one with loop on the top bearing cover).
[quoted text clipped - 3 lines]
- the motor (new pistons and valves and I converted it to an electric
fuel
pump).

How did you power the electric fuel pump? In the event that you didn't
....
consider providing it's power in a manner that the power is removed if the
engine is not running, even though the ignition may be "on". Often, this
is
accomplished by powering it through an oil pressure switch.

Eisboch

Stern Drive Conversion
 

I suspect you will find it does not have a raw water pump in the outdrive.
The raw water pump is just to supply cooling water to the engine. I gather
you have not taken the outdrive apart. No real reason to if it does not
supply cooling water. You should change it's fluid and check the old fluid
for signs of water.

You need to wire your electric fuel pump to the cranking terminal of the
starter and to an oil pressure switch.

Best of luck with your new boat :-)

"Bennie" u31788@uwe wrote in message news:6ddc6c80655ed@uwe...
Sorry for being a bit slow but I thought there was a potential problem if
the
RAW water pump on the Stern Drive was just ignored....
Hopefully I can learn this stuff quickly.

Bennie wrote:
I don't know......It is stamped redone on the outside of the stern drive.
Is
it OK just to run the Sterndrive without pipes hooked up since the water
route through the Transom goes to a blank off plate? I was worried about
the stern-drive it's self needing cooled.... The boat definitely has a
through hull raw water pickup that flows through the heat exchanger and
out
via the exhaust.
Remember I am OK with anything mechanical (engines, gearboxes etc) but I
am
unfamiliar with the needs of sterndrives....

Converted to what?

[quoted text clipped - 8 lines]
My assumption is that the pre-Alpha drive has been converted
somehow.....!!!!!