Mercruiser re-power. What motors and outdrives to look for and to avoid?

[HT32BSX115]

Normally a 5.7l is 260hp unless it is a MAG and then it would be 300hp.

And it would also probably be an EFI engine

 

[thumpar]

My EFI is rated at 250hp. I am not sure why the 10 missing. It was really early on for EFI in those years though.

 

[pckeen]

No Title

Ok, I have a line on a 1990 donor boat with a 5.7 Alpha One. I will be getting it mechanically inspected. Any troublespots with the 1990 model that I should be worried about?

 

[HT32BSX115]

That's a fairly "plain-vanilla" 350/Alpha package. 2bbl or 4bbl carb?

probably something like 250 hp or so. It should perform very well in your boat!

 

[pckeen]

I admit - I'm not sure - I forgot to ask when I spoke to the mechanic. The inspection is now done on a 1989 Sea Ray, Mercruiser 5.7, engine number 0C605284. All looks good. As for the specific questions I had, there were no signs of any issues with the oil - no cracked block, and no indication of a problem with the manifold. The boat was reoprted to be running fine. Steering was good, stator and alternator good. The compression numbers were:
1 - 145
2 - 150
3 - 140
4 - 155
5 - 150
6 - 170
7 - 140
8 - 140

The only cylinder that give me pause is number 6 - the 170 reading. The mechanic I spoke to said the motor was good, he wouldn't be concerned about the 170 reading, and that this motor was pretty much bulletproof. What are your views on this?

Do I understand correctly that this motor is the 260hp 5.7L 350 MAG, used from 1983-1993

 

[pckeen]

Just realised the last post is in the wrong forum. I'll post the question over in the mercruiser forum.

 

[pckeen]

Thanks for the advice everyone - I've made the deal - and will be picking up the donor boat in September.

 

[pckeen]

I'm back on the hunt for a donor boat or motor and outdrive - the sale on the donor boat fell through.

I have an outdrive for a mid 1970s Mercruiser 165. I am taking a look at a late 80s Mercruiser 260 tomorrow, that comes with gimble housing and motor, but no outdrive. Will the outdrive from my 165 fit this motor?

 

[Bondo]

I have an outdrive for a mid 1970s Mercruiser 165. I am taking a look at a late 80s Mercruiser 260 tomorrow, that comes with gimble housing and motor, but no outdrive. Will the outdrive from my 165 fit this motor?

Ayuh,.... It'll bolt on, But,.... the Ratio is all wrong,....

 

[pckeen]

Well that 260 Mercruiser was a bust. Compression on one side seemed good: between 135 and 149. On the other side the compression tester went above 200 on the first two cylinders and was still climbing. When I released the pastries gas, or more likely mixed gas and water came squinting out. The tester was full of it. A mechanic friend tells me that there isn't enough gas drawn into a cylinder to do that. The most likely explanation is water getting into the cylinders.

 

[HT32BSX115]

Well that 260 Mercruiser was a bust. Compression on one side seemed good: between 135 and 149. On the other side the compression tester went above 200 on the first two cylinders and was still climbing. When I released the pastries gas, or more likely mixed gas and water came squinting out. The tester was full of it. A mechanic friend tells me that there isn't enough gas drawn into a cylinder to do that. The most likely explanation is water getting into the cylinders.

Well, it possibly has a bad manifold and/or riser (and depending on how long it's been that way, a couple of rusty cylinders)...............but it's not necessarily a bust if you can buy it cheap enough. wrecking yard 350 engines are plentiful

 

[pckeen]

With all the work I have on the yellow submarine, I want to minimize my work on the motor as much as possible - I'm trying to find a donor boat with a good running motor and outdrive.

 

[pckeen]

I have a line on a couple of motors and outdrives.

This is a 1982 260 with what the seller says it's a new outdrive. What would a fair price be for this?

http://s1362.photobucket.com/user/pckeen/media/output_zps8yrtkib2.jpg.html?filters[user]=136189189&filters[recent]=1&sort=1&o=0

 

[Alumarine]

I have a line on a couple of motors and outdrives.

This is a 1982 260 with what the seller says it's a new outdrive. What would a fair price be for this?

http://s1362.photobucket.com/user/pckeen/media/output_zps8yrtkib2.jpg.html?filters[user]=136189189&filters[recent]=1&sort=1&o=0

Link doesn't seem to work.

 

[pckeen]

Hmmm, try this.

 

[pckeen]

I have a line on a donor boat in Ham Lake Minnesota. Is there anyone in the area who could take a look at it for me?

 

[HT32BSX115]

I have a line on a donor boat in Ham Lake Minnesota. Is there anyone in the area who could take a look at it for me?

This is a 1982 260 with what the seller says it's a new outdrive. What would a fair price be for this?

That drive in the above picture looks like a #1 drive. Pretty hard for it to be "new" and I am not sure I would trust a seller that made the claim.....

If I was "restoring a cool older boat like you're doing, I would probably avoid the really old Mercruiser drives and maybe try to find newer ones focusing on the GEN-II drives if possible

One way would be to look for donor boats that have had the drive severely damaged or stolen. This way you get a good engine and transom mount. Then you could just pick up a new SEI drive and have a pretty nice "package".

 

[pckeen]

Thanks. I'll avoid the 260. I'm now looking at a boat with a 1993 4.3 Alpha II. Anyone know what the hp should be from that year?

 

[HT32BSX115]

Thanks. I'll avoid the 260. I'm now looking at a boat with a 1993 4.3 Alpha II. Anyone know what the hp should be from that year?

I seem to remember 190HP (220 for the newer EFI models I think......same as a carbed 5.0L V-8!) which would probably perform quite nicely in your boat. A V-8 would not really burn much more fuel (for medium cruising speeds) but would afford much better hole-shot and acceleration. Nothing at all wrong with the 4.3L V-6 though!
If your alumnium boat is lighter than a similarly sized fiberglass 25ft cruiser, it should be just fine ......considering that it might have came new with the 165hp inline............ I would not want a 4.3L V-6 in a heavy cruiser (but I am THOROUGHLY spoiled with the 7.4L Bravo III in my 21ft cuddy/sport cruiser!!!)

 

[pckeen]

Now that's nicely powered. I would prefer a 5.7, but the 4.3 is a Alpha Gen II, at a good price.