Fletch's 1976 170 Rebuild

[kedd]

I plan on using toothpaste and elmers glue.

I wasn't by any means taking a sh ot at your work.


Here is a really good fairing compound.
The nice thing about this one is it will also adhere to epoxy and poly and both will adhere to it.
There are a ton out there but I really liked the outcome with this one.

Check the website and look at their catolog

Adtech P-14 ultra white
http://www.fiberglassservices.com/catalog.htm


Kedd

[Fletch170]

HA! Hey man, no offence taken. As I've explained to a few people here, I've been around boat my whole life, and know a good amount, however, I know next to nothing about ACTUALLY DOING the fiberglass work. Thus, everyone here has been extremely helpful. Gran and Seabob have talked me off the ledge as I was about to do something really dumb....so I take constructive critisizim very well! Thank you for the insight! I'll check out that fairing compound.

-Fletch

[Fletch170]

HELP!

Hey guys, got a line on a motor for my boat, it's a 1999 115 Mercury. Just like the one in this link.

The seller says it weighs around 350 pounds. Is this motor going to be way too heavy for my 17?

http://www.google.com/imgres?q=mercury+ ... x=36&ty=59

[gran398]

Hiya!

Link is broken presently...but guess what? Fitz runs twin Merc 115's just like the one you're discussing...and they run GREAT!

He loves 'em! How much are they asking?

 

[Fletch170]

$2950 for the motor.

The motor cowl is HUGE. The owner said it is heavy, but i'm wondering if it is any heavier than an original 115 they would have put on this boat.

[fitz73222]

$2950 for the motor.

The motor cowl is HUGE. The owner said it is heavy, but i'm wondering if it is any heavier than an original 115 they would have put on this boat.

338# plus prop and oil. Not that much heavier than the old in line 6. These are a little different than your average engine. These are 2+2 engines. Meaning they idle on two cylinders and jump to four cylinders @2000 rpm. It actually works pretty well and they get excellent fuel consumption at trolling speed. This is not done electronically but through modified fuel delivery on the bottom two cylinders and are oiled seperately without firing. I guess this was Mercury's early answer to cylinder deactivation and competitive 4 stroke idle fuel consumption. No one has really been able to explain to me why Mercury chose this design but maybe the the Boatdood can explain. The engine actually idles well for whats going on.

[MarshMarlowe196]

These are 2+2 engines. Meaning they idle on two cylinders and jump to four cylinders @2000 rpm. It actually works pretty well and they get excellent fuel consumption at trolling speed. This is not done electronically but through modified fuel delivery on the bottom two cylinders and are oiled seperately without firing. I guess this was Mercury's early answer to cylinder deactivation and competitive 4 stroke idle fuel consumption.

Wow, I never knew that about those Merc's.  That's a cool idea.  8)

No one has really been able to explain to me why Mercury chose this design but maybe the the Boatdood can explain. The engine actually idles well for whats going on.

Being surrounded by original builds all day, the Boatdood doesn't visit the rebuild forum often.  I'll see if I can summon him ...  

[Boatdood]

Heh, that was pretty cool Marsh. I looked out in the night sky and there, silhouetted in a search light's powerful beam, was the outline of a boat, and I knew I was needed. I'm thinking Batman didn't have text messaging, but the Boatdood does.

Merc's 2 plus 2 engine is an interesting engineering story, but not the one you'd expect. We all know about the Tower of Power days of Mercury when they built those in line six cylinder engines from 60hp all the way up to 150hp, but in the late 80's their days were coming to an end. Mercury entered the loop charged induction days back then and there was a pretty good internal battle going on as to how to build the engines. The Tower guys won the in line battle as far as the 115hp, and 125hp was concerned, and the bean counters won the one size fits all battle where the pistons and rods were concerned. That's how the 75 hp through the 125 hp ended up with the same internals. So the engineers were tasked with building an in line four cylinder engine using a set piston and rod and have it produce up to 125 hp, and they did. Only glitch was it wouldn't idle. No matter what they did, until one of them came up with the idea of killing two cylinders at low speed by giving them such a tiny idle fuel orifice that the engine could get oil distribution, but not enough fuel to fire. Engineering finally had their task accomplished, and marketing came up with the 2+2 idea and made it sound like a good thing.

In reality it was a pretty good engine. In fact the Mercs of that period were mostly all pretty good engines. They had a sweet 150 hp V6, and some of the quietest, most fuel efficient little three cylinder engines on the market ranging from 40 to 60 hp.

Weak links, and every builder seems to have a few kinks; the early production engines had too tight cylinder to piston clearances and tended to lock up if you ran them too hard with low hours. Most of them were weeded out early as you could expect. The oil injection pump was driven by a SS worm gear riding on a nylon ring gear. The nylon did what you would expect it too and stripped, thereby stopping the worm gear. At least they had an alarm hooked up to a motion sensor.

Funny story. I was a service manager at a Merc dealership back in those days and had a pretty good group of techs working for me. One guy got a 2+2 115 to do some work on and spent quite a bit of time before he came to me triumphantly. Heh man, it looks like Merc screwed up and put the wrong idle jets in this engine. It was only idling on two cylinders, but I got it running on all four by changing out those orifices. Now I just got to get it to idle right.

Good luck with that buddy.

[gran398]

These are 2+2 engines. Meaning they idle on two cylinders and jump to four cylinders @2000 rpm. It actually works pretty well and they get excellent fuel consumption at trolling speed. This is not done electronically but through modified fuel delivery on the bottom two cylinders and are oiled seperately without firing. I guess this was Mercury's early answer to cylinder deactivation and competitive 4 stroke idle fuel consumption.

Wow, I never knew that about those Merc's.  That's a cool idea.  8)

No one has really been able to explain to me why Mercury chose this design but maybe the the Boatdood can explain. The engine actually idles well for whats going on.

Being surrounded by original builds all day, the Boatdood doesn't visit the rebuild forum often.  I'll see if I can summon him ...  

 

Fletch,

That 115 Merc would be a honey-pie for you. Overpowered...nope. If you got it...90% of the time, you'd be cruising, 34 mph at 3900 rpm. Achieving very respectable mileage.

Put 3 bigger boys on her...going fishing, loaded up...she'll shine.

Tell them 2K firm offer if it passes your mechanic's compression test.

If they cry...sorry...its a buyer's market in this economy.

Boatdood...saw your post pop-up as was posting this...and read it. Very interesting, those old days that us old guys remember. Back when we ALL had an extra nickel...and everyone was buying new boats. Damn...

My regret is... it used to be, you worked hard, provided for your family...you were middle-class, but...we all had NICE boats. Maybe two or three.

I hate it for our kids these days.

Back to the Merc.

[Boatdood]

Heh Scott. Who you calling an old guy? I only know this stuff because some old guy told it to my dad, and he told it to me. I don't even know who Batman is. Speaking of that, did you see Catwoman? Smokin!!!!!!!!11

[fitz73222]

Heh, that was pretty cool Marsh. I looked out in the night sky and there, silhouetted in a search light's powerful beam, was the outline of a boat, and I knew I was needed. I'm thinking Batman didn't have text messaging, but the Boatdood does.

Merc's 2 plus 2 engine is an interesting engineering story, but not the one you'd expect. We all know about the Tower of Power days of Mercury when they built those in line six cylinder engines from 60hp all the way up to 150hp, but in the late 80's their days were coming to an end. Mercury entered the loop charged induction days back then and there was a pretty good internal battle going on as to how to build the engines. The Tower guys won the in line battle as far as the 115hp, and 125hp was concerned, and the bean counters won the one size fits all battle where the pistons and rods were concerned. That's how the 75 hp through the 125 hp ended up with the same internals. So the engineers were tasked with building an in line four cylinder engine using a set piston and rod and have it produce up to 125 hp, and they did. Only glitch was it wouldn't idle. No matter what they did, until one of them came up with the idea of killing two cylinders at low speed by giving them such a tiny idle fuel orifice that the engine could get oil distribution, but not enough fuel to fire. Engineering finally had their task accomplished, and marketing came up with the 2+2 idea and made it sound like a good thing.

In reality it was a pretty good engine. In fact the Mercs of that period were mostly all pretty good engines. They had a sweet 150 hp V6, and some of the quietest, most fuel efficient little three cylinder engines on the market ranging from 40 to 60 hp.

Weak links, and every builder seems to have a few kinks; the early production engines had too tight cylinder to piston clearances and tended to lock up if you ran them too hard with low hours. Most of them were weeded out early as you could expect. The oil injection pump was driven by a SS worm gear riding on a nylon ring gear. The nylon did what you would expect it too and stripped, thereby stopping the worm gear. At least they had an alarm hooked up to a motion sensor.

Funny story. I was a service manager at a Merc dealership back in those days and had a pretty good group of techs working for me. One guy got a 2+2 115 to do some work on and spent quite a bit of time before he came to me triumphantly. Heh man, it looks like Merc screwed up and put the wrong idle jets in this engine. It was only idling on two cylinders, but I got it running on all four by changing out those orifices. Now I just got to get it to idle right.

Good luck with that buddy.

Once you get into the differences between the carbs between the top two and bottom two cylinders it becomes apparent that the upper castings of the bottom two carbs are different. Mainly, there are no idle air passages in the low speed chamber where the low speed adjustment would normally be. The adjustment screw bosses are plugged. The engine appears to be fed oil through a check valve system fed through a delivery adjacent to what was the transfer port area of the block.  Now, running two of these engines as twins I have got to know their "qurickiness" . These engines want to run on the bottom two cylinders also when on a flush with no back pressure and will spit at idle; trying to run on all four and rev up and spit unless trimmed all the way in. Trimming out raises the idle speed and lean spit condition. In the water with back pressure, renders a stable idle quality. I have been completely through the carbs, intake gaskets, timing, syncronization and correct float height. These engines have had this propensity to do this since new; now with 300 hours since 95' so they are still baby's. The only other major update was a stator recall in 96' and were changed from blue to red stators; if part numbers are relevent let me know but there was no base idle timing change based on the recall. So if you can walk me through these details you will be my Mercury BFF! Next, I'm working on my 53' Mark 20 with a "Scintilla" magneto that I need coils and condensers for. It is a beautiful original that I found laying in a barn but no double line gas tank; thats right a Mercury with a pressure fed fuel system; do you know of a double line gas tank and fuel connector for a pressure fed Merc from the early 50's BFF Mercury pal? This engine was the little sister to the Mark 20H hydro version.

[Boatdood]

Fitz, the problem with the stators was in the iron core. The plates were stamped out of sheets and the edges were sharp ninety degree angles. The wire wrapped around them was coated with insulating material, but the sharp angles caused the tiny little wires to bend too sharp and break the insulation. This allowed the current to short out. The later stators had rounded corners to avoid the insulation break down. No change in timing was needed that I remember.

The lean condition you've noted in your engines when you trim them out is typical of carbed two stroke engines. Gasoline, like water, runs down hill. When you trim the engine out some of the fuel runs out the throat of the carbs and it's lean. Trim it back down and the fuel runs back into the crankcase eventually ending up in the combustion chamber enrichening the mixture. All outboards are affected by the back pressure created by the water level. Some more than others, but it's always a good idea to adjust the engines for both fuel mix and idle speed when they are running in the water, and at the depth they will normally run.

For those old pressure fed Mercs you'll need to find some old guy to help you. Waaaaaay before my time. Seriously I like old things. Shucks, I even like my wife.

[fitz73222]

Thanks,
Of all the Mercs in stable, these are the only ones that are trim sensitive to idle quality. Its only on the flush so no big deal. In the water no problem. I'm an engineer, so these details keep me up at night until i understand the reasons! Anyway, thanks for your help and i still am fascinated by this I4 2+2 story; so point me towards more detail than you could ever imagine about this design if available...

[Boatdood]

Fitz, I've never chased the 2+2 story around the web so I don't know where it will lead or where to send you. All my info comes from the inside story as told to me by a couple of Merc reps. Coincidentally one of my outside sales reps is an ex Merc rep, and he and I had a conversation just last week regarding the "one size fits all" inclination of bean counters to get the cost of production down, and the 2+2 came up. He was one of the guys on the inside who witnessed the development, quite by accident, of a pretty neat and unique outboard. Back in the years when that outboard was one of the latest and greatest I had the honor of attending a tech school in Sanford Fl. taught by one of the best instructors I've ever experienced. Wish I could remember his name, Les something, but he was a soft spoken intensely intelligent man who was able in one week to give me a whole new perspective into Merc outboards, and outboards in general. He is the first to relate the true sequence of events to me regarding the evolution of the 2+2.

[gran398]

As Scott (Circle Hooked) noted on another thread...our house is a large house, and has many rooms.

But the biggest room here is the family room.

Enjoyed the great and informative discussion tonight. Thanks.