Did I Kill My Merc?

Last summer my Merc died (1994 Mercury 100 model 1100412PD version ELPTO)

Local mechanic tested and said replace voltage regulator - no go. So next, he said, replace the coil.

Nobody local had the special flywheel puller - you can guess the rest. Used a regular gear puller and a really big sledge hammer, being advised that it wouldn't hurt it. Manual says otherwise. Finally got it off, had broken two flywheel magnets, got a clean used flywheel, put it all back together. It immediately sheared the upper crankshaft key so I pulled the flywheel again (easily came off) and replaced the key.

It started and ran great for about 30 minutes. Actually, it ran better than ever before.

Then it started hesitating and "clunking". Started making a lot more smoke than usual. Whimpered to a halt and now won't start. It turns over and sometimes kicks like it is about to start, but never does.

Maybe it broke the key again, but the engine is turning over so I think not.

Any suggestions (other than RTFM, and don't listen to your friends even if they've been fixing boats for 40 years)?

Pull the flywheel.You have probably broken the key again and it has gone off the timing.It will turn over regardless.

That would be GREAT news! I'll try that tomorrow.

Is there any way to "firm up" the shaft so that it doesn't keep breaking keys? Torque it until it hurts us both? Glue? Sand? Kidding....

But should I clean it with alcohol or something, so that there is absolutely no grease on it?

I'm an American but summering in Sweden, and I don't have all the proper tools, and here each tool is hundreds of dollars. Also, since it's summer, the boat mechanics aren't working. Not kidding. They say "tow it here and we'll fix it over the winter." Then they charge about $2,000 for winter storage since I won't be here to retrieve it as soon as its fixed.

So it's up to me....sadly.

You will need to torque it tight,supposed be to 120ft lbs or 163Nm,so,until it hurts.A smear of grease to keep it from corroding and I hope a broken key is all it is.And I thought it was only here that a body could get ripped off like that.

All Hail Haventaclue, who actually has a clue! Yes, the key was broken again. Another new key fixed it, and it runs great. I only hope that it doesn't keep breaking keys.

I rigged a wrench extension of 2.5 ft and applied about 50 lbs of force, calibrated from constantly weighing my wife's suitcases before we fly.

What is the best way to stop the shaft from turning as you apply torque? I stuck a crescent wrench between the starter gear and the flywheel gear - it worked, but seemed like abuse.

Thanks, Haventaclue!

..." smear of grease to keep it from corroding "

NOOOOO!!!! That's the problem, and it will shear again--trust me.

Listen to this and you'll see what's going on: I repair lots of old Mercs in the small, 2 banger size. To start them up (since the recoil is in the hood--dumb idea) I use a 1/2 inch drill on the flywheel nut. If I do it wrong the nut loosens up when the motor fires up. Several times the nut came right off, but the motors kept running at idle (as I carefully shut it down).
And the key did NOT shear! Why? Friction of the tapered joint, friction that ANY amount of lubrication destroys. The key simply locates the flywheel, it does NOT keep it from moving.

Here's what you MUST do or you'll be stranded out there:

1. Remove the flywheel (again!)

2. Remove the key.

3. Buy some valve grinding compound (at a good auto store) and smear a light coating it on the joint

4. Put the flywheel on and rock it back and forth a few dozen times to "lap in" the two surfaces.

5. Remove all traces of the grinding compound, replace the key, and put the 'wheel back on.

DO this right and you'll never have another issue.

Jeff

Goes against the keep from corroding idea but makes sense.I have bought a small single cyl Seagull,'65, for a kicker and I think I'll do this.Have given up on the idea of a '69 Merc 110 to match the black beauty,'69 Merc800,for the moment