1974 Merc 85hp vs. 1974 Johnson 85hp

[utah_aviator]

hello everyone,

I know there are a lot of you out there with direct experience with one or both of these outboards. I'm trying to get an idea of the differences between these two outboards of this approximate vintage. Let me know if you can provide any of the following information on either or both models:

1. Weight
2. Real world Fuel Consumption @ approx. 3500-4000 rpm range & at WOT
3. Power Output and Power Band - overall operating performance
4. Ease of Working On
5. Ease of obtaining parts
6. Known Design Weaknesses or Components that fail too often
7. Any other info that you feel characterises either motor

They both seem like really great outboards and I'd like to hear what everyone's experience has been!

Thanks.

 

[Scaaty]

Re: 1974 Merc 85hp vs. 1974 Johnson 85hp

Wanna go fast and have fun on a light boat MERC
Fish, putt..the Johnny (I'd buy both..but thats just the old softy in me..)

 

[MercFan]

Re: 1974 Merc 85hp vs. 1974 Johnson 85hp

As far as I know, and correct me on this please. The Merc is 85hp measured at the crank shaft, and the Johnny is 85hp measured at the prop shaft. So the Johnny is theoretically the stronger engine of the 2, in the water.

 

[jimmbo]

Re: 1974 Merc 85hp vs. 1974 Johnson 85hp

In 1974 all outboards were rated at the crank.

Merc 66.6 cubic inches, 234 lbs, 2.3:1 gears
Johnson 92.6 cubic inches, 252 lbs, 2:1 gears

Both were rated 85hp. so they should be close in top speed. The Johnson, with more displacement should have more torque and therefore better accelleration with the merc having better part throttle fuel economy.

Both engines were crossflows. Merc called theirs Direct charging, but it was just a variation of a crossflow

Ease of servicing... The johnsons seemed easier to work on. The merc, often required special tools.

Parts for any 1974 outboard could be difficult to locate

Both engine designs had been in production since the 1950s so they were pretty much

 

[tashasdaddy]

Re: 1974 Merc 85hp vs. 1974 Johnson 85hp

i've run both, but i'm a diehard OMC guy, johnson/evinrude hands down.

 

[ezmobee]

Re: 1974 Merc 85hp vs. 1974 Johnson 85hp

I can still get just about any part I could need for my '73 Johnny 85.

 

[Chris1956]

Re: 1974 Merc 85hp vs. 1974 Johnson 85hp

I cannot comment on the Johnny, but parts for the Merc are still available since there was a lot of engines and years that shared the inline parts. A silly example is that I took the LU mounting studs off my '73 850 and used them on my '93 135HP V6.

if the 850 was used in salt water, you might stay away from it, since the exhaust side water jackets rot out over time. Alos if that motor has a distributor, replacement parts are available but pricy.

BTW - i always thought that motor was excellent. it was lightweight and compact, and easy to tune up. The carbs, fuel pumps, props, wiring harnesses, cowling, midsections, lower units, cooling system, motor mounts and ignition system was common to many inlines from the late sixties to the late 80s.

 

[utah_aviator]

Re: 1974 Merc 85hp vs. 1974 Johnson 85hp

Hey guys, GREAT info! It's just the kind of comments I was looking for. Anyone have any real world fuel consumption numbers besides WOT setting?

 

[JasonB]

Re: 1974 Merc 85hp vs. 1974 Johnson 85hp

It really depends on the boat, I can't speak to the Merc for fuel consumption, but the Johnny is a bit thirsty. I have a '76 85hp (just like the '74) on a 16' tri-hull. Back when we used it as a fish/ski and I ran it WOT most of the time, with 4 adults and 15gal of fuel on board, we could ski/tube all day. If I just ran in a straight line up the lake and back, I could go 10-12mi on 6 gal at near WOT. That Johnny V4 has great torque for skiing. With 500lbs of people in the boat, I could pull up a 230lb skier. With the same load, I was able to pull up a 175lb slalom skier -barely. I was running a 17p prop. Dropped to a 15 and thought I could pull anything. Top speed with the 17 was about 36-37.

Only repairs I have done in almost 10 years is new bendix gear (old one literally worn out), starter solenoid (was able to peck on and get it working to save a fishing trip), carb rebuilds (not necessary at the time, but figured it was due, same with head gaskets), and a powerpack right after I bought it. Even with a failing PP, she fired and ran enough for me to go about 5 miles to the ramp with one bank of cylinders cutting out. Otherwise, feed it good gas, quality oil, grease the fittings yearly, and I expect it to last as long as I need it. Great reliable motor.

Common parts are readily available. The tough one might be the LU if you ever needed one. It is specific to most, but not all, V4's from '73-'77. The show up on e-bay constantly though if you know what to look for.