Armature Plate? (25 Evinrude)

[yelladog]

Well, took this motor out today(79 25 Enivrude) after alot of work and it ran great, but idles alittle rough. Local outboard shop said these motors were bad about the armature plate retaining ring(#12) getting worn and in return, alot of movement in the armature plate which shakes the points around.Took hood off at idle and noticed some movement. When accelerated up some it stops the movement. Could this be the problem ?? #12 in pic

 

[itstippy]

Re: Armature Plate? (25 Evinrude)

I dunno how much armature plate wiggle you could see with the flywheel on and the motor running, but yes, armature plate wiggle will cause poor running at low RPM's. You have to pull the flywheel and the armature plate, then rap the armature plate mount with a dull (dull!) cold chisle in three (four?) spots to firm it up. The Joe Reeves super fix. Paul Moir has described the method too, with pics even. Gee I wish I could get at my links library from the old forum format!
Joe or Paul or someone else will be along soon with the link you need.

 

[Joe Reeves]

Re: Armature Plate? (25 Evinrude)

(Magneto Armature Plate)
(J. Reeves)

If the armature plate has a a loose fitting, wobbling motion (the plate that the points, coils etc are attached to), it is usually caused by a slightly worn support ring. This allows the point setting to change erratically as the armature plate turns.

The cure is to remove the armature plate so that the support which is attached to the powerhead with 4 screws is visible. Then, with a screwdriver and hammer, or some tool of your choosing, and looking straight down at the support ring, make an indentation at what would be called the 12, 3, 6, and 9 O'clock positions. Install the armature plate and check for a smooth turning wobble free movement.

You may need to do that procedure a few times to obtain the proper fit (not too tight, not too loose), but it's worth the effort.

 

[F_R]

Re: Armature Plate? (25 Evinrude)

The picture you posted is not for a 1979. In fact the wone you show is in my opinion one of the better designs they had. The ring 12 is hardcoated for wear resistance. It is 10 that the others are talking about whacking to tighten it up. I'd be careful doing that, you may get it too tight. Earlier models had the bushing cast into the armature plate and a flat plate in place of 12. That kind did wear pretty badly.

Having said all that, a 1979 is totally different. You can see it at http://epc.brp.com/default.aspx?brands=ej&lang=E

 

[Chinewalker]

Re: Armature Plate? (25 Evinrude)

Incidently - your 1979 has no points to "shake around". Your motor is breakerless CDI ignition. The armature rides on two seperate surfaces. There is a center hub that is cast into the crankcase/block, and a second, bolted-on ring with a plastic bushing around it. They can get a little loose, but usually replacing the outer ring or doing joe's fix on the center hub can take care of the problem...

- Scott

 

[yelladog]

Re: Armature Plate? (25 Evinrude)

Im sorry guys, this is a 1973 25 Evinrude. I have a 79 suzuki also and get the years mixed up. The pic I posted is for a 1973, the motor I have. Will this fix still apply to the 73? Sorry Again

 

[Paul Moir]

Re: Armature Plate? (25 Evinrude)

Absolutely. It's an excellent fix. Just go light on it like F_R said and test a few times.

If you make the armature plate too tight, it's not difficult to remove the ring and tap out the dents shallower. It makes a heck of a difference when it's tight. Not only by rectifying the timing, but also the engine will make a lot less noise.

Here's a visual on what Joe Reeves is explaining:
Click here

 

[F_R]

Re: Armature Plate? (25 Evinrude)

OK, if you really do think you have excess movement. But they can slop around a lot before it actually gives trouble. You do have the improved version with the hardcoated bearing, and yes it does have points. If you bend anything to tighten it up, it will be the brass ring, number 10. But be careful, you may make it too tight. Examine the coil for evidence of rubbing on the flywheel magnets. Maybe the movement is being caused by mechanical interference there. Also, the magnets' attraction to the coil can cause slight back and forth rotational movement of the plate noticeable at slow speeds...that's nothing to be concerned about. It would be up and down tilting motion or side to side lateral motion that would be of concern. Bending the ring will help the tilting, but not side to side lateral.

 

[yelladog]

Re: Armature Plate? (25 Evinrude)

Ok Thanks, I will take a closer look at it and see exactly where the slack is. While on the water, I took the hood off and actually took my finger and applied presure to the armature plate and it did change the idle. I dont expect this old motor to run perfect, but if something can be corrected, I would like to do so. Thanks F R!

 

[yelladog]

Re: Armature Plate? (25 Evinrude)

Just wanted to say thanks to Paul also, great pic!

 

[yelladog]

Re: Results! Armature Plate? (25 Evinrude)

Re: Results! Armature Plate? (25 Evinrude)

Hello, I done the Joe Reeves repair and the slack seems to be gone in the armature plate. When I started the motor, It seemed as though It was idleing higher than before. It has good throttle response and idles good, but maybe alittle high. Does this sound normal? Can I adjust the idle on this motor? (73 25 Evinrude)

 

[Paul Moir]

Re: Results! Armature Plate? (25 Evinrude)

Re: Results! Armature Plate? (25 Evinrude)

Have you done the link & sync yet?

The throttle stop on your one is at the throttle control gear. This is where the throttle shaft from the tiller grip (I'm presuming here) turns 90 degrees and goes straight up into the engine compartment. I don't think I'm describing it very well, so go to the BRP diagram site, have a look at the "EXHAUST HOUSING" section, and it's part #84, 85 and 83.

 

[yelladog]

Re: Armature Plate? (25 Evinrude)

Thanks Paul, Also I was wondering what would be signs of the support ring being to tight. If the trottle(tiller grip) turns freely, shouldn't it be ok. Just wanted to make sure its not to tight. Thanks