Information on 1975 25 HP Johnson?

[Acton]

I'm looking at a 25 HP Johnson that the dealer has advertised as a 1985. Looking online based on the decals and the green lower unit I've identified it as a 1975.

I own a 78 9.9 HP evinrude and from what I know from reading on Leeroys Ramblings about the 9.9/15 HP series, motors that where made before 1976 had no telltale hole and used a "points" system vs a "CDI" ignition system with a power pack when starting the motor. I've heard that these older motors where less desirable because of this, and if something goes wrong "resetting the points" can be a real pain. This video on youtube seems to corroborate that this is the case for the 25 HP motors as well. . .

https://www.youtube.com/watch?v=n5Lgt5BeeV0

I was surprised that Leeroys Ramblings didn't have any information on this series of motors. . . . I was warned not to buy the older pre 1976 motors in the 9.9/15 HP series because of the "points" ignition system, does anyone have any experience with the pre 1976 25 HP OMC motors?

I'm currently looking at a used 14ft deep v with a 63" beam which is a big upgrade from the 12fter I have now. It's a great deal and it comes a galvanized trailer which is also an upgrade for me since I'm using a harbor freight boat trailer at the moment, which isn't galvanized. I'd pick up the boat and the trailer alone for the price advertised to be honest, but getting around quicker with a 25 HP does sound appealing. . . . Even on my small 12fter my 9.9 evinrude couldn't get my boat above 13mph. Most likely because I'm on the bigger side, I'm 6'1" and weigh 270lbs. . .

I plan to take a look at the boat and motor next week, and I'm hoping to learn more about this motor before then. I'll do the usual compression check and lower unit oil check. I noticed that in some of these older motors even though there's no telltale you can check water flow from the exhaust port on the lower unit. Anything else I should check for?

I've attached a picture, looks just like the motor in the video I linked too on youtube.

 

[flyingscott]

That is a great motor very reliable. Don't let points scare you it's a good system. The ignitions are similar to but not the same as the 9.9/15 systems, the 25 hp motors don't have the reliability issues the smaller motors have. Yes the points are harder to service because the flywheel needs to be removed but not impossible for a do it your selfer. I have had points last 10 yrs or more in the OMC motors. I would test drive it to make sure the lower unit is working properly or get a warranty. One thing I always liked about points is I never had both sets fail at the same time so I could always get back on 1 cylinder. A CDI ignition when it fails can fail all at once leaving you stranded. You will know it's pumping water a lot comes out the exhaust relief.

 

[racerone]

The stories are all out there.--------There is nothing wrong with points systems.----------In fact if you can not get a coil for these older systems you could make one.--------------Doubt that the average workshop can make a CD module or an ECU unit.---Just price the parts / availability for the ignition of a Johnson / Evinrude 9.9 built from 1996 to 2000

 

[Acton]

Alright, you guys have me convinced then.

When I go take a look at this motor, whats the best way to see that both cylinders are getting good spark? I just want to make sure there's no problems at all with the ignition system before I make a purchase. I'm also going to make sure that the dealer I'm buying from will be willing to service this motor. I know a lot of shops around here refuse to work on these older motors because they use the flywheel magneto with breaking points system.

I've got very limited experience working with motors myself. The most I've done on my 9.9 was throwing in a new impeller, putting in a new carb kit and replacing the fuel pump. Taking off the flywheel is above my head. I took a look at these directions that someone posted in another topic concerning the ignition system in a 25 HP Johnson for that year and my eyes crossed. I know these directions are for a different HP motor, but the person from that topic mentioned the procedure is the same for the 25 HP Johnson.

http://www.outboard-boat-motor-repa...on 3 HP 1952-1967 Ignition System Tune-up.htm

 

[hardwater fisherman]

No Title

If it is a 1975 25 hp then it has a lo-tension magneto. Which was a system used during the mid 70s and possibly into the 80s on some models. The coils are external, not like the ones shown in your link. There will be a driver coil under the flywheel, along with points and condensers. EDIT The decals do appear to be a 1975 model.

 

[racerone]

It is not hard to learn how to work on that magneto.----It is simple and straight forward work !

 

[Guest]

These motors (22 cu. in. twins) have been a mainstay for OMC since 1956, they are truly one of the most forgiving engines to own and enjoy. I have a 1973 25 Johnson, my dad had the 73 18 Evinrude version, both solid mills.

You can still get coils and just about anything else for them because they were in production so long.

A bargain if you find one in nice shape!