1975 Evinrude 25HP No Start, Post Tune up, Magneto Plate slop

I think I was going about posting wrong by tagging onto someone else's unanswered post.

This motor was given to me and was running SO poorly. It would hardly idle, and at lower RPM's would do this bum.bum.bum.bum.bum.WHACK.bum.bum...and the whole motor would **** it's head to the side, so to speak. The pull start assembly came off at the ramp the last time I ran it from stripped threads. Those are all right after a couple of helicoils. But I decided to do a full tuneup/carb job.

I also installed an electric start from another motor, so I've been able to turn the motor really well in this troubleshooting.

So, I rebuilt the carb, and put on all new ignition components. There appears to be spark, and I even sprayed some fuel mix while starting, but nothing.

It backfired once while initially starting but that is all.

On my first attempt, I did have the magneto coil too far out at first, but that is fixed (I brought it back flush with the bosses). (it has two external coils and one under the flywheel)

I'm pretty sure what is going on is that the groove on the bottom of the flywheel is catching on the magneto plate. It is only at one point in the rotation, and you can feel the throttle bind at this point in the turn of the flywheel.

There is some slop in the magneto plate. Is that brass bushing/bearing inside the magneto plate replaceable? Could this be my problem? If so, why did it run before?

Thanks in advance for any wisdom or other advice on this project.

Matt.

Re: 1975 Evinrude 25HP No Start, Post Tune up, Magneto Plate slop

Update:

The catching really is from the coil underneath. I have to back it back behind the bosses for it to not catch. I did that, and now the engine will just barely begin to fire, but then quit. It is as if it hungers for the timing to advance (timing) or for more fuel (fuel linkage/magneto plate sync). My points are gapped right, and I followed the book on throttle sync. Any ideas?

mm

Re: 1975 Evinrude 25HP No Start, Post Tune up, Magneto Plate slop

Another update: I can start the motor if I open the throttle on the carb with my fingers while starting. This is with the mag plate advanced as much as possible in neutral. It will run in mid to high RPM's but no idle. The coil is pulled back as far as possible under the flywheel, but could it still be catching with slop in the magneto plate?

Incidentally, the starter motor and starter side of the solenoid get SO hot so fast with even a few short starts. Is this normal?

mm

Re: 1975 Evinrude 25HP No Start, Post Tune up, Magneto Plate slop

Just an update, the entire problem is related to slop in the magneto plate and hold down assembly. Specifically the problem is the wear in the brass bushing inside the magneto plate that rides on collar of the block, and the brass hold down ring. The slop is both fore/aft--side/side as well as a teeter tottering motion. I had it rigged for a bit, but not a long term fix. Currently looking for a not so worn out used assembly.

Re: 1975 Evinrude 25HP No Start, Post Tune up, Magneto Plate slop

check the salvage yards in the top secret file.