1970 750 sterndrive wanted

Hi does anyone have an old 750 sterndrive for sale or know where I can get parts.
Regards
Michael ph 0429993727

Michael, I'm not aware of a 750 stern drive! Did you mean to say 250 drive?

In or around 1970, the 200 stern drive was being replaced with the 250 stern drive.

If 250, you will see a fill port within the Intermediate housing, and an insert within the supension fork.
These also had bevel cut gears in the lower unit.

I have a 250 drive that is mostly complete ( missing some parts from the reverse latch I think) sitting in my shed. I pulled it off my 1969 boat since it was the wrong ratio for a V8 about 9 years ago and replaced it with a 280. Previous owner's mechanic sealed the unit with hardening gasket cement and I was unable to take the drive apart ( did not have a big enough torch). My original plan was to just replace the lower 1/3 which has the reduction, but I got a good deal on a whole 280 of the correct reduction at that time. PM me if you are interested. Per my profile, I'm located "on the Jersey Shore".

Hi, thanks for your reply, it is a 750 sterndrive they are 1972, I still have the old manual, however they were not that popular when they first came out so there isn't many around, after my post, due to the age I have decided to re power the vessel think it will be best as it is a commercial vessel and does a lot of work
cheers Michael.

Michael, years ago I got a call from a man who operated a Gil Net boat. He needed some drive work done.
This boat had the standard 290 stern drives on it.
He had 6,000+ hours on these drives and had not done much more than change gear oil, bellows, water neck fittings, etc.

I was happy to see how well they had held up.


I'd go with a later Volvo Penta AQ series stern drive. Perhaps a C or later drive.
No Gimbal suspension, nor all of the crap that goes along with a gimbal system stern drive!



.

http://www.ebay.com/itm/Volvo-Penta...hash=item51f3b92486:m:m1HiDnJNoraPYcDwI7N0HuQ
That is a odd looking duck it just looks like a weak design to me.

Yes Kim, that is an odd looking duck.

Now that I've seen the e-bay aution photo, I do recall it......... I just never logged the 750 into my brain, nor I have ever seen one up-and-close.

If I were to buy a classic boat to restore, I'd put a late ( 280 or up to SP-C ) drive in the boat. Stay with the 200 series technology, i.e. stay away from the gimbal mount drives. Also... if you have the room, find an extended housing which have Borge Warner mating flanges and take a standard bobtail inboard engine. This will give you the widest choice of power options since just about every engine on the marked comes with a B/W bobtail mount. It also moves the engine about 4" fwd ( as I recall, Ricardo knows for sure). To avoid a weak point in this Volvo system, I'd also go with thru hull water inlet w/ strainer and thru hull exhaust. The passage port thru the transom to the drive on this series is a bit undersized and does not meet the minimum exhaust port diameter specs of even a modest carbed 5.7L Merc. I don't know if you "run" a lot, or idle a lot in your work, but thru transom ( with mufflers) will keep backpressure managed if you spend a lot of time running your engine @ or below max displacement speed. I've measured back pressure @ displacment speeds with the 280 3 hole transom shield and it sits right on the manufacturer (MERC) recommendations for MAX WOT pressure. A MAX WOT, it's waaay over.

Cheers Bob, Ill take your advice as I am not that good on motors with legs, have always had boats with prop and shafts in the past, my work is mainly idle for 4 hours a day and a lot of turning involved, my boat is about 10 ton just don't want to be under powered however also with not to much fuel consumption, I travel 12 hours to my fishing grounds then a week at low speed pulling nets.
regards Michael

The assumption I've had is that when stern drive designers design their drives, they assume that most of the time the boat will be on a plane. On Volvo drives, this means that the exhaust port is exposed and not underwater. If you spend a lot of time at low speed, then you will have about 1/2 psi extra back pressure on the exhaust system. While this may not seem like a lot, the reason that I started on the whole thru hull exhaust system on my boats is due to the fact that I've spent a fair amount of time with my engine at idle while drifting for fish in a particularly nasty local inlet (Barnegat). I've had two different engines on different boats "load up" and falter and then often stall when the throttle is opened ( to avoid a close encounter situation) when I did this. My solution on both boats and eventually on all subsequent boats was a conversion to thru hull exhaust. The first boat I did this on was NOISY even though it was only a 1.8L engine. The second boat was reengined to a 318 CID 225 HP. That boat went thru hull from the gitgo with a pair of SUDBURY neoprene mufflers ( Center rise manifolds were reversed to shoot fwd, two elbows, with mufflers set alongside the engine, below the manifolds and out the back.) My current boat was reengined with a 5.7L and there was too much in the way of "stuff" in the way to do this again, i.e. "down and out", so on this boat, I went back @ right angles and out the far corner of the transom with fiberglass mufflers (3" ports). Sudbury is out of muffler business. I discovered after the fact that there is a Volvo stainless dual muffler system for V8s that sits on the back of the engine and goes out the back of the transom. If I had to do it over again, I'd go this way.

As part of this thru transom exhaust and thru hull water inlet conversion, I now only have one bellows ( and a shift cable) and no hoses or "water elbows" that are a maintenance issue, from the transom to the leg.

And of course, a cooling system with a heat exchanger and a 160F T'stat.

Thanks Mate, yes I agree with the assumption that the design is for being on the plane, i'm thinking of doing away with the leg and putting a shaft and prop threw, as I am rarely on the plane due to the weight I carry and I run at 1500 rpm as any more I burn to much fuel, i.m just getting it out of the water this week to pull the old 750 off the back and see what is best to do.
cheers for your help
regards
Michael

Besides the difficulty in doing that revision to your hull, you would loose the ability to more easily clear line fouls from your prop...

shade said:

Thanks Mate, yes I agree with the assumption that the design is for being on the plane, i'm thinking of doing away with the leg and putting a shaft and prop threw, as I am rarely on the plane due to the weight I carry and I run at 1500 rpm as any more I burn to much fuel, i.m just getting it out of the water this week to pull the old 750 off the back and see what is best to do.
cheers for your help
regards
Michael

Click to expand...

Greetings from Finland.

If you still need parts (or someone needs) for those 750 stern drives, i got two of those. I got also two twindisc marine clutches, trim cylinders etc. CV joint rubber boots and zinc anodes i don't have anymore. PM me for part quotes.

These 750 stern drives are extremely rare nowadays because it was made mainly for professional use and it's massive drive compering to basic consumer 270 - 290 drives. I have an old pilot boat from 1980 with two 70C engines / 750 drives.

so358 said:

Greetings from Finland.

If you still need parts (or someone needs) for those 750 stern drives, i got two of those. I got also two twindisc marine clutches, trim cylinders etc. CV joint rubber boots and zinc anodes i don't have anymore. PM me for part quotes.

These 750 stern drives are extremely rare nowadays because it was made mainly for professional use and it's massive drive compering to basic consumer 270 - 290 drives. I have an old pilot boat from 1980 with two 70C engines / 750 drives.

Click to expand...

This thread was started back in February of 2017..... almost two years ago.
The OP posted 4 times only..... last entry being 2-23-2017.
I highly doubt that he is still in the market..... but ya never know!