magneto spacing

[guajiro0192]

:facepalm:Hi all
Still trying to fix this motor. I fix one thing to have another issue! I want to know what the spacing between the flywheel and the magneto on a 1975 25hp evinrude (25502b) should be. I also only have one mag, not two as I have noticed. This motor did run for a while...:facepalm: a while ago. It though was popping out of gear. I fixed that issue with a lower unit that I picked up from the now closed sea chest on wpb. I cannot get this thing to run now. adjusted the pts to 020, plugs to 030, fixed the fuel/water issue.... now I see that one plug stays soaked in fuel while the other looks good. I also noticed (by mistake) that when the fuel line was disconnected, the motor started and ran pretty good, until it ran out of risidual fuel. I have also noticed that the carb leaks fuel from the throat while in choke. Man... I a tired of typing! if anyone can answer at least the mag ?, I would most appreciate it.

By the way, I just got a carb rebuild kit and a pump rebuild kit.

Thanks so much,

Tony

 

[JB]

Re: magneto spacing

You have a dual magneto, not a single. I always used a dollar bill (about .010") to set the spacing between the coil cores and the flywheel magnets. Don't know if that is spec, but it always worked for me.

 

[guajiro0192]

Re: magneto spacing

So under the flywheel, I should have 2 mags, one on each side of the plate? I only have one. I do have two external coils though. Maybe this has been an issue all along. I get spark on both cyls. I will try to post some pics of the plate.

Thanks

 

[Daviet]

Re: magneto spacing

By the parts breakdown of your serial number you should have one coil under the flywheel and two external ign coils.
Look on the posts that the coil under the flywheel mounts on and they should be machined on the outside in and arch that matches the flywheel. Mount the coil so that the laminations are even with the arch on the posts, rotate the flywheel by hand, with the plugs out, to make sure the flywheel does not rub on the coil laminations.
Sounds harder to do than it actually is.

 

[1946Zephyr]

Re: magneto spacing

On the mag plate mounting bosses, you will see where it is machined off a little bit. Line the face of the coil with that machined surface, perfectly I usually use a utility knife blade to check for evenness. There should be absolutely no air gap showing from the top of the coil face, to the bottom of the machined boss.

 

[guajiro0192]

Re: magneto spacing

Thanks for the info. I adjusted the mag, and got a far better spark. Now the motor started, but sputtered and would die. I choked it, and it would crank, but then die. I just rebuilt the carb, and still have a little fuel that seems to come out of the throat of the carb as if it is flooded. At one point while messing w the low idle, it started, but I had to keep the idle hi using the throttle. It sputtered a bunch. I will check the fuel to make sure that it is not contaminated. I also rebuilt the fuel pump, and that seems fine. Any info is greatly appreciated.

 

[Daviet]

Re: magneto spacing

Try pumping the primer bulb real hard and see if you can see any fuel dripping out of the carb throat. If there is gas in the throat, the needle and seat is not sealing off and flooding the engine.

 

[guajiro0192]

Re: magneto spacing

I tried that, and didnt see any coming out. Could it be back-flowing from the manifold? Hopefully things will crank up fine. I am hoping that it is just a little water in the fuel. If not, I will try to change out the condensors. After that, who know... sledgehammer? And to think that this all happened after the motor actually ran a bit, until the forward gear messed up. I replaced that, and now it is all going to hell in a handbasket. Maybe itis a sign of the end of times that is supposed to happen tomorrow. Hope not! Got a 18 pack of PBR waiting for me. Don't knock it unless you have really tried it! Thanks for the tip.