Bob,

Your original post no longer shows up but I think from some responses I may
have missed the point that your engine is salt water cooled. If that is the
case, I would not rebuild it. My engine was run in fresh water till I
bought the boat so is probably worth an overhaul.

I was told at a boat show that the new Yanmars drop right into the same
space as the old ones. These are great engines and a new 3GM is probably
your best bet.

BTW more often than not when I'm advising someone on repowering a sailboat,
I'll find that they have a 3 cylinder engine but a prop that can only use
the horsepower of a 2 cylinder. You very well might be able to put in a
lighter and cheaper 2GM that would be happier running closer to its design
point and give you the same performance you have now. It wouldn't be quite
as smooth but the 2QM running a 2 blade prop in my boat is as smooth as I
could ask for. Fuel economy will also be slightly better taking the same
horsepower out of one less cylinder. The 2GM should fit easily on the same
beds as the 3GM with more room at one end.

I can give you a rough answer on this if you tell me:

Displacement
Length on Waterline

I can give you a better answer if you an also tell me:

Current HP and reduction gear ratio
Prop size, pitch' and number of blades
Propeller aperture size
C
Current max RPM and speed at that RPM

--
Roger Long

Bob wrote:
....
Yes, that was my thought too. But there are some folks that say
"upgrade" to more modern model. ANd then mention part availibility
problems on 30 year old models. But when I went to my local tractor
dealer they didnt blink an eye when I asked for a rebuild quote on a
marine qm yanmar. The problem was the $6000 he quoted for the rebuild.
Thats a lot of money for a 30 yo motor.


That sounds like a lot - I have a friend that replaced a tired 3GM
with a new 3YM and he claimed it was well under $5K. The footprint
was almost identical, I think there were a few changes for the
plumbing, but the job was done in a day. He didn't need a
transmission, and there was 100% access so YMMV. You should shop
around a bit before listening to one quote.

But when I think of trying to modify an existing space for a diffrent
engine I start having flashbacks of a cutting torch and endless detail
modifications. I really like the idea of an exact foot print...... easy
out easy in. But????

Bob wrote:

The problem was the $6000 he quoted for the rebuild.
Thats a lot of money for a 30 yo motor.


Reluctant Bob


Geez, Tbat $6K should just about pay for a new
3YM30, and I'd bet the footprint is nearly
identical. You wouldn't have to rebuild the
stringers, but you might have to have custom
"vibration" mounts built to hit the bolt holes.

I'm in a similar situation except that I've got a
1983 3HM Yanmar sitting in the Irwin. It was
supposedly "overhauled" just before I bought the
boat, but overhauled can mean a lot of different
things depending on who is saying it. Right now,
it starts and runs great, so I'm going to let it
keep running, but I've already marked it down in
my mind as suspect for long voyages.

Have you gotten quotes on a new 3YM30? I'd also
think about going to fresh water cooling if I were
you.

Don W.

Yo ,, Bob... $6,000 for a rebuild of a motor? Something is wrong with this
picture.

I've priced out a few sailboat aux's recently. I think the price for a new
one was around $5,000.

Where did you get this quote? Did you call engine rebuilders? Something
just doesn't sound right.


"Bob" wrote in message
ps.com...

NE Sailboat wrote:
My thought .. the engine fits the stringers, and therefore it would be
easy
to take out and put back in.

So,, why not just get the engine rebuilt.

Can't you take it out, bring it to a rebuild place, get it all done over
with new this and new that .. then bring it back and put right back where
it
came from?

Yes, that was my thought too. But there are some folks that say
"upgrade" to more modern model. ANd then mention part availibility
problems on 30 year old models. But when I went to my local tractor
dealer they didnt blink an eye when I asked for a rebuild quote on a
marine qm yanmar. The problem was the $6000 he quoted for the rebuild.
Thats a lot of money for a 30 yo motor.

But when I think of trying to modify an existing space for a diffrent
engine I start having flashbacks of a cutting torch and endless detail
modifications. I really like the idea of an exact foot print...... easy
out easy in. But????

Reluctant Bob

NE Sailboat wrote:
Yo ,, Bob... $6,000 for a rebuild of a motor? Something is wrong with this
picture.

I've priced out a few sailboat aux's recently. I think the price for a new
one was around $5,000.

Yes, I agree. I walked into a local John deer tractor dealer and made
the mistake of starting with, "I have a sailboat...." Actually the
quote was $5800 and some change.

i just did some more searching and found a rebuilder that has two
3QM30H RW for $4400 each. But rebuilds do differ from shop to shop. But
the tractor quote did seem way out of line. Another factor to consder
is the QM weighs about 750 lbs! I under stand the newer models run 1/2
that. Maybe more room for fuel??? Nah, rum.

Bob ,, the BETA 16hp,, maybe not quite what you are looking for but ...

only weighs 205lbs!

I've looked at that engine. It isn't the most powerful deisel but ...
205lbs! Isn't that sweet.

=============================
"Bob" wrote in message
ps.com...

NE Sailboat wrote:
Yo ,, Bob... $6,000 for a rebuild of a motor? Something is wrong with
this
picture.

I've priced out a few sailboat aux's recently. I think the price for a
new
one was around $5,000.

Yes, I agree. I walked into a local John deer tractor dealer and made
the mistake of starting with, "I have a sailboat...." Actually the
quote was $5800 and some change.

i just did some more searching and found a rebuilder that has two
3QM30H RW for $4400 each. But rebuilds do differ from shop to shop. But
the tractor quote did seem way out of line. Another factor to consder
is the QM weighs about 750 lbs! I under stand the newer models run 1/2
that. Maybe more room for fuel??? Nah, rum.

Bob wrote:

Yes, that was my thought too. But there are some folks that say
"upgrade" to more modern model. ANd then mention part availibility
problems on 30 year old models. But when I went to my local tractor
dealer they didnt blink an eye when I asked for a rebuild quote on a
marine qm yanmar. The problem was the $6000 he quoted for the rebuild.
Thats a lot of money for a 30 yo motor.




I think $2000 per cylinder is a pretty standard charge for rebuilding a
diesel. $6000 for a three-lunger is not out of line. This is an engine
commonly used in sailboats. If its the original engine, a rebuild will
probably last the remaining life of the boat.

On Sun, 21 Jan 2007 00:47:54 -0600, xorbit wrote:

I think $2000 per cylinder is a pretty standard charge for rebuilding a
diesel.

That's the going rate for something like a 300 hp, 3,000 pound Detroit
6-71.

Wayne.B wrote:
On Sun, 21 Jan 2007 00:47:54 -0600, xorbit wrote:

I think $2000 per cylinder is a pretty standard charge for rebuilding a
diesel.

That's the going rate for something like a 300 hp, 3,000 pound Detroit
6-71.


Yes..... Da ya think parts made since 1938 might have somthing to do
with it. Belive me, if I could fit a one of thoes green two stroke
screaming beasts in my boat I would in a heart beat. But am stuck with
a japanese manufacture that appearantly decided to forge their parts
from unobtainium.
Buy American Bob

Wayne.B wrote:
On Sun, 21 Jan 2007 00:47:54 -0600, xorbit wrote:

I think $2000 per cylinder is a pretty standard charge for rebuilding a
diesel.

That's the going rate for something like a 300 hp, 3,000 pound Detroit
6-71.


Yes..... Da ya think parts made since 1938 might have somthing to do
with it. Belive me, if I could fit a one of thoes green two stroke
screaming beasts in my boat I would in a heart beat. But am stuck with
a japanese manufacture that appearantly decided to forge their parts
from unobtainium.
Buy American Bob