How to break Flywheel nut?

[miichael18]

How can i break the flywheel nut loose? the motor keeps turning over. it has holes in flywheel but they dont go all the way though. I was thinking about using a impact wrench to jar it loose. Is it a standard thread? lefty loosy righty tighty?

It is a 1974 70hp evinrude. Nut is a 1 5/16 im pretty sure

 

[BoatBuoy]

Re: How to break Flywheel nut?

Impact wrench will do it. That will work without a flywheel-holding wrench and you're correct on the threads. Replace with a torque wrench though, not an impact wrench and for that you will need a method for holding the flywheel.

 

[F_R]

Re: How to break Flywheel nut?

A strap wrench is the standard tool for holding the flywheel from turning. You can buy one or make your own from a piece of wood and nylon strap. It's a standard right hand thread counterclockwise to loosen. An impact wrench is great for taking it off, but don't use it to put it back on unless you want to destroy the flywheel....a new one will set you back several hundred $. For the same reason, make durn sure the impact is set to loosen before zapping it. You will need a 3-bolt type puller to get the flywheel off and a torque wrench to put it back on. Torque the nut to 70-85 ft/lbs. Tapers on flywheel and shaft absolutely must be clean and dry before installing and torquing the flywheel

 

[MarkV_Deep6]

Re: How to break Flywheel nut?

You can make a flywheel holder with two pieces of metal. A long piece for the handle and a short piece bolted near the end of the long piece. Drill holes in the Y shaped end of the two pieces of metal large enough to allow bolts that will fit into the holes on the flywheel used to pull it. This makes a large spanner wrench that will hold the flywheel and let you apply enough force to remove the nut, and also let you torque it during reassembly.

 

[robtown]

Re: How to break Flywheel nut?

Since we're on the subject of flywheels here, I recently replaced mine with one from the salvage yard, along with a brand new OMC Timer Base.

I pulled the wheel because in the process of starting (engine hasn't run in quite some time), it backfired a few times and sheared the key. I noticed that the inner "trigger" wheel appears to be rubbing against the trigger in the new timer base.

Should I try to adjust this? Or will it rub down a bit and be all good? So far I haven't run the motor for more than 20 seconds at a time (with muffs), but I'm taking it out today for a shakedown.

72 Johnson Looper, 50 hp, electric start, electric shift ...BTW

 

[miichael18]

Re: How to break Flywheel nut?

I thought about putting it in gear and holding the prop with another socket while i turn flywheel. Would this work or could it harm anything?

 

[KYHunter2]

Re: How to break Flywheel nut?

Not a good idea at all .

You'll be putting all the torque on the drive shaft, prop shaft , gear case, splines , etc. etc.

Granted these components are under stress during operation .

But, unless you run up on a log,etc. they're able to rotate .

The methods expressed are the correct way.

Its usually very easy , with an impact , and strap wrench.

Outboards are no place to experiment, unless you have deep pockets.

KYHunter