Merc vs. Johnson question

[bgc]

Re: Merc vs. Johnson question

Didn't OMC get bought by the French?


Keep the Merc.......

 

[wired247]

Re: Merc vs. Johnson question

Didn't OMC get bought by the French?

If Canada is a part of France then, yes. Mercury got bought by a bowling ball manufacturer that also makes Bayliners.

 

[dazk14]

Re: Merc vs. Johnson question

The OMC is certainly a simpler motor to work on... but at the end of the day it's condition,condition,condition.

 

[emckelvy]

Re: Merc vs. Johnson question

I saw this and couldnt help but share it

Mercury 1500hp outboard! Set the water on fire!!!

1500 HP. Wow! that means my 73 Mercury 1150 is actually 1150 HP!!!! What have I been thinking! LOL!

If only we had some of the stuff that the Dude in that ad is on!!!!! :facepalm:

 

[jimmbo]

Re: Merc vs. Johnson question

Thats one way to look at it . The other way is you have a longer stroke with the 4 cylinder which gives you much more low end torque with good usable power up to 6000 RPM . You dont have the reed blocks straddling the crank with a less than ideal labyrinth seal reed block arrangement that is costly or impossible to replace. The V4 and V6 engines give you a much easier breathing one venturi per cylinder. The 3 circuit V4 carbs idle much smoother and transition off idle much better than the 2 circuit L6 carbs. Mercury finally got the single cylinder trim setup right in the late 70's and got into the same sort of ignition and charging system that OMC had been using for a decade. Blind bored blocks, no cylinder heads, etc. QUOTE]

Longer stroke means higher pistons speeds and loads on connecting rods.Never had a reed fail on my mercs, my uncles Johnson ate a couple. V4 and v6s, including the merc V6 use another piston ring to seal the cranckshaft to the crankcase. It to ends up being a 'less than ideal labyrinth seal" OMC engines used to use belt driven generators later switching to stator alts which merc used back in the fifties. Mercury was the first to use Electronic CD ingition. BTW Omc pretty much redesigned the ignition system every year, once they did go electronic. The Carbs on the mercs sharing 2 cylinders allowed smoother off-idle transition cause the flow was not being stopped when the reeds closed as it would be if it fed only one cylinder, it just changed direction. Until the mid 80s OMC didn't use the 3 jet carbs, that was an attempt to get the two thirsty five(235) to be less of a fuel hog, even though it only put out 185hp at the crank. Headless design was great, can't have a blown gasket. From 1973 til 1979 OMC used a trim sytem that was just as slow as Merc, two cylinders outside the transom bracket. The V6 used the integral system fro the start in 76, in 77 the 140 got the integral but the rest of the V4 didn't until 79. I will conceed merc didn't bring an integral one til 84.
As for your comparisions... Which 140s are you comparing to the 150? There were 3 different 140s All V4s 99.6 crossflow, and 110 cu in looper and 122 looper. Since they were rebuilts that could skew the results depending on how good the rebuilder was. My 115 was faster than the 140 both in holeshot and top end.

Looking at the Merc Help forum and the OMC Help Forums, It seems there are more problems with OMC, just by the number of posters. Since Mercury for many years was the leading marine manufacturer I could assume the is more old merc product out there, and running.

 

[bgc]

Re: Merc vs. Johnson question

If Canada is a part of France then, yes. Mercury got bought by a bowling ball manufacturer that also makes Bayliners.

....I was hoping to work in a white flag reference.....they also make pool tables

 

[bgc]

Re: Merc vs. Johnson question

The OMC is certainly a simpler motor to work on... but at the end of the day it's condition,condition,condition.

They are definitely much simpler to work on.....

 

[wired247]

Re: Merc vs. Johnson question

Longer stroke means higher pistons speeds and loads on connecting rods.Never had a reed fail on my mercs,

And Ive never had a piston or rod fail on any of my OMC's even at 6500 ish.

my uncles Johnson ate a couple.

My Uncle's Mercury lost 2 cylinders . He can't get the block sleeved locally . Easy job by any machine shop on a cylinder with removable heads.

V4 and v6s, including the merc V6 use another piston ring to seal the cranckshaft to the crankcase. It to ends up being a 'less than ideal labyrinth seal"

Even Mercury abandoned that hokey crankcase reed contraption. Ever priice a new set of reed blocks. $400 if you can find ONE.,

? OMC engines used to use belt driven generators later switching to stator alts which merc used back in the fifties.

Look inside a new 3.0 liter Merc. Whats old is new again. Nothing wrong with alternators. Easy to work on and easy to change.

Merrcury was the first to use Electronic CD ingition.

Yet they stuck with distributors up until the late 70's on the inlines

BTW Omc pretty much redesigned the ignition system every year, once they did go electronic.

Not true

The Carbs on the mercs sharing 2 cylinders allowed smoother off-idle transition cause the flow was not being stopped when the reeds closed as it would be if it fed only one cylinder, it just changed direction.

Nice theory but not true in practice. In practice, the carbs need to be run WAY too rich at idle to get them to make the transition from idle to main jets smoothly without stumbling. Gas consumption suffers and fowling of plugs happens

Until the mid 80s OMC didn't use the 3 jet carbs, that was an attempt to get the two thirsty five(235) to be less of a fuel hog, even though it only put out 185hp at the crank.

Ive got a whole drawer full of 1980 to 1985 three circuit V4 carbs that beg to differ. Even the 90 had them in 1980. Much better transition from idle. Most of the problems people have setting up the carbs on inlines can be traced to that design. If the two circuit carbs were so great Mercury would continued to use them on their V6's. They didnt and neither does anyone else.

Headless design was great, can't have a blown gasket.

Can't sleeve the block without great difficulty and can't increase the compression easily either. Don't even get me started on the cooling leak machine inside the exhaust chest

From 1973 til 1979 OMC used a trim sytem that was just as slow as Merc, two cylinders outside the transom bracket. The V6 used the integral system fro the start in 76, in 77 the 140 got the integral but the rest of the V4 didn't until 79. I will conceed merc didn't bring an integral one til 84.
As for your comparisions... Which 140s are you comparing to the 150? There were 3 different 140s All V4s 99.6 crossflow, and 110 cu in looper and 122 looper. Since they were rebuilts that could skew the results depending on how good the rebuilder was. My 115 was faster than the 140 both in holeshot and top end.

My 140 crossflow blew my 150 high port out of the water.

Looking at the Merc Help forum and the OMC Help Forums, It seems there are more problems with OMC, just by the number of posters. Since Mercury for many years was the leading marine manufacturer I could assume the is more old merc product out there, and running.


Most mercs, with the exception of the goofy 2+2 motors and the inlines are good or even great motors. The inline was just a concept that hung on too long despite some advances even by mercury that should have doomed it much earlier.

 

[nwcove]

Re: Merc vs. Johnson question

bottom line is....." if you want to get somewhere first....run the merc"......"if you want to get somewhere and back...run the omc".

 

[Chinewalker]

Re: Merc vs. Johnson question

Looking at the Merc Help forum and the OMC Help Forums, It seems there are more problems with OMC, just by the number of posters. Since Mercury for many years was the leading marine manufacturer I could assume the is more old merc product out there, and running.

Not exactly... There are more Johnrude posts because there are more Johnrudes. LOTS more. Johnson alone had built a million outboards before Mercury was out of diapers. And there are a LOT more 1950s and 1960s Johnrude related posts filling up the boards as a larger percentage of Mercs from that era have been scrapped out due to lower unit casualties because of Mercury's reluctance to embrace stainless in their shaft materials. OMC started using stainless in the 1940s, while Mercury didn't get into it until the 1970s.

 

[bgc]

Re: Merc vs. Johnson question

Not exactly... There are more Johnrude posts because there are more Johnrudes. LOTS more. Johnson alone had built a million outboards before Mercury was out of diapers. And there are a LOT more 1950s and 1960s Johnrude related posts filling up the boards as a larger percentage of Mercs from that era have been scrapped out due to lower unit casualties because of Mercury's reluctance to embrace stainless in their shaft materials. OMC started using stainless in the 1940s, while Mercury didn't get into it until the 1970s.

How about the Mercury Automatic Transmission......PITA to work on....

 

[jimmbo]

Re: Merc vs. Johnson question

How about the Mercury Automatic Transmission......PITA to work on....

Right up there with the Electric shift and Hydro-electric shift. Don't forget the itty bitty gearcases with a 23:20 ratio and tiny propellers on the V4s almost to the end of the 1960s

 

[jbjennings]

Re: Merc vs. Johnson question

Not exactly... There are more Johnrude posts because there are more Johnrudes. LOTS more. Johnson alone had built a million outboards before Mercury was out of diapers. And there are a LOT more 1950s and 1960s Johnrude related posts filling up the boards as a larger percentage of Mercs from that era have been scrapped out due to lower unit casualties because of Mercury's reluctance to embrace stainless in their shaft materials. OMC started using stainless in the 1940s, while Mercury didn't get into it until the 1970s.

That's what I was thinking the OP should know about and check before making the call on which motor to keep. Personally, if I had gone through the merc and was satisfied that it was in good running condition and had a good lower unit/non-pitted/scored/grooved driveshaft on it that was well sealed, I'd keep it. I think the inline mercs are really sharp looking motors compared to the more boring looking OMC's, although I believe the OMC's to be of superior reliability on average. The Mercs never had problems with speed and power that I know of.
I do believe there to be a HUGE NUMBER Of 70's and late 60's Mercs with good powerheads and missing/crappy lower units due to the problem mentioned above.
jMO,
JBJ

 

[Chinewalker]

Re: Merc vs. Johnson question

Right up there with the Electric shift and Hydro-electric shift. Don't forget the itty bitty gearcases with a 23:20 ratio and tiny propellers on the V4s almost to the end of the 1960s

Thing is - the electric and hydro electric shift units worked very well - when they worked. They just didn't like water. Once fishing line entered the propshaft seal and allowed water into the system, things went wonky. Also, the electric shift units really aren't that difficult to work on, unlike the Merc autotransmission units.

 

[bgc]

Re: Merc vs. Johnson question

Thing is - the electric and hydro electric shift units worked very well - when they worked. They just didn't like water. Once fishing line entered the propshaft seal and allowed water into the system, things went wonky. Also, the electric shift units really aren't that difficult to work on, unlike the Merc autotransmission units.

I didn't think the shift solenoids were avaiable anymore?

 

[Chinewalker]

Re: Merc vs. Johnson question

We weren't discussing parts availability, just ease of working on them. Parts availability for older Johnrudes tends to be better than older Mercs on most things, including shift solenoids, most of which are still available at a dealer - just pricey.

 

[jbjennings]

Re: Merc vs. Johnson question

I own a hydroelectric shift 50hp OMC and it's still going great. It's never needed a clutch dog or whatever, because it always makes perfect shifts. Not saying I like the system, but as said, it sure works good.
I will say that I loved the Mercury motors like the 20hp, 9.8hp of the late 60's and 70's because they were such smooth runners and had such great power back when they were new. They were cold natured and unless in absolutely perfect tune, were hard to start at the beginning of the day. Once warmed up, they were incredibly easy to start. My father used to beat on those motors mercilessly and could not tear them up. He worked in the oil fields and had huge arms during that time and one morning while pull starting that merc he caught me under the chin with the back of his elbow and knocked me from the second seat from the back, to the bow of the 15' boat we were in. Anyway, I still run a '73 mercury 65hp VERY regularly on my crappie boat in winter and spring and even though the 3 cylinder mercs were not the best mercury ever built, they still just keep on running.
Anyway, I think the mercury is worth keeping if it's in good condition. I enjoyed the big merc/OMC arguement, since I like arguing and haven't been involved in a big merc/OMC one in a while.
I wish I was smart enough to change the water pump on an old 50's merc automatic tranny, because I think they are neat looking motors, but I doubt I'd want to take one of 'em duck hunting when it's cold outside.

I'm feelin' the need for a Chinewalker "motor wall" pic, BTW....
Got any interesting motors lately, Chinewalker??????
JBJ

 

[Chinewalker]

Re: Merc vs. Johnson question

JBJ - Nothing terribly interesting. Actually thinning the herd a bit. Down under 200 motors now!

 

[metriccrescentwrench]

Re: Merc vs. Johnson question

Dan, The Merc is like a throughbred race horse, and the Johnny is a plow horse, IMHO. Are pulling a wagon or do you just want to ride the horse.....

I'm wondering if anyone here knows what brand holds the outboard engine all out speed record.

Hint - the engine used for the record run wasn't black.

 

[sutor623]

Re: Merc vs. Johnson question

I'm wondering if anyone here knows what brand holds the outboard engine all out speed record.

Hint - the engine used for the record run wasn't black.

Was it the Sears Eska air-cooled single cylinder series??