Johnson Flywheel with a stripped puller hole

[Anonymous]

Pulling on the outside edge will destroy the flywheel.

[Mumbles]

This Big Twin might have had its flywheel grabbed on the outside instead of using the devoted holes for pulling. Has anyone ever tightened a puller so much it pulled the flywheel right off the hub? Doing this would ruin your day and open a big can of worms! 😥

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[jerry-ahrens]

Never pulled one off the hub, but I have had to go up to a 3/8 Heli Coil insert once, to get one off. That baby was on there! This was a 57 Big twin, that was purely original. I ended up putting an electric start flywheel on anyway.
You DO NOT want to use an outside type puller that grabs the rim of the flywheel. It will bend or break the flywheel, right around the hub.

[Buccaneer]

That’s one gnarly looking flywheel remains!
Reminds me of a snowmobile clutch that I had to
cut on the crankshaft…….. no fun.

quote Mumbles:

This Big Twin might have had its flywheel grabbed on the outside instead of using the devoted holes for pulling. Has anyone ever tightened a puller so much it pulled the flywheel right off the hub? Doing this would ruin your day and open a big can of worms! 😥

Prepare to be boarded!

[fleetwin]

quote NJ-boatbuilder57:

quote Chris_P:

quote NJ-boatbuilder57:

There’s always the other option of using a wide-stance puller that can clamp the outside of the flywheel.

Im assuming you are kidding, but for those that are not aware, NEVER do this!

OK…I’ll ask: why not? I wasn’t kidding…..but the post above about “flexing” makes sense.

The flywheel is really held in place by the taper fit between the flywheel and crankshaft. Those tapers actually lock/seize the flywheel to the crankshaft, which is why they are tough to remove. Trying to pull the flywheel off with one of those jaw pullers not only pulls up/flexes the outer ring of the flywheel, it is not pulling on the tapers which are locked together. Using the OMC puller pulls up directly on the tapers.
You can see how tough the OMC puller is just by looking at it, comparing it to something like a harmonic balancer puller. It is not just the puller plate that is tough, the OMC screws and washers are a tough grade as well. The puller drive screw is a very fine thread as well. Finally, the OMC puller disk/plate has a drilled hole for the large rod that is included in the OMC kit which allows you to hold the puller/flywheel in place while tightening the puller drive screw.
In short, the OMC puller is an absolute must for any technician or collector that frequently works on OMC outboards from the 50s to present….

[Buccaneer]

My harmonic balancer puller had done great….. up until now.
But….., I haven’t worked on anything bigger than a 10 hp until
now either. I have a couple of derelict 35 hp to eventually work
on, so guess I better come up with something better!

The flywheel is really held in place by the taper fit between the flywheel and crankshaft. Those tapers actually lock/seize the flywheel to the crankshaft, which is why they are tough to remove. Trying to pull the flywheel off with one of those jaw pullers not only pulls up/flexes the outer ring of the flywheel, it is not pulling on the tapers which are locked together. Using the OMC puller pulls up directly on the tapers.
You can see how tough the OMC puller is just by looking at it, comparing it to something like a harmonic balancer puller. It is not just the puller plate that is tough, the OMC screws and washers are a tough grade as well. The puller drive screw is a very fine thread as well. Finally, the OMC puller disk/plate has a drilled hole for the large rod that is included in the OMC kit which allows you to hold the puller/flywheel in place while tightening the puller drive screw.
In short, the OMC puller is an absolute must for any technician or collector that frequently works on OMC outboards from the 50s to present….[/quote]

Prepare to be boarded!

[Mumbles]

quote Buccaneer:

That’s one gnarly looking flywheel remains!

That photo was of a motor for sale on Ebay once. I had to save it for reference!

Here’s what I did find in my ’55 Big Twin though. Signs of a backyard mechanic or lousy welder using an acetylene torch to remove the hub!

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[Buccaneer]

Not only Independence Day, celebrating our freedom from the Britts,
but I’m celebrating the flywheel coming off! Whooo Hoooo!

First rule in being "cheap" is to never throw anything away.
I dug thru my bucket of pullers I’ve been collecting the
last 40 years. While I didn’t find an OMC out of the box puller,
I found an old, old wheel puller, whose plate was about 5/8"
thick. Drilled three oversize 1/4" holes in it to match up to flywheel,
and put a new point on the bolt in the lathe.
While the puller bolt wasn’t fine thread, it’s size and
never seize made it turn okay. The end of my 18" breaker
bar fit nice in one of the puller "wheel bolt" holes, to be
used as a handle while tightening the bolt. Popped off in
about 20 seconds whereas I played around off and on all
day yesterday with my harmonic balancer puller.
Just confirms that "bigger is better".

I did have one senior moment in the project…. I made three spacers
out of aluminum tubing to put on the bolts so I couldn’t screw them too
far into the flywheel. Thought I was pretty smart until I started
tighten the puller bolt and wondering why it was turning so easy.
I was crushing the aluminum tubing. 🙄
Substituted nuts for tubing and things went better!
Wanted to get some proper length, hardened bolts, but alas,
the local hardware store was closed today.

Glad it came off so I can tinker with the points and clean
out all the metal scrap from installing the heli-coil.
Hope you have an equally happy 4th!

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Prepare to be boarded!

[bobw]

Like the old saying- necessity is the mother of invention. Great job of making something work with what you had available. Now you have a new OMC puller!

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[frankr]

quote Mumbles:

This Big Twin might have had its flywheel grabbed on the outside instead of using the devoted holes for pulling. Has anyone ever tightened a puller so much it pulled the flywheel right off the hub? Doing this would ruin your day and open a big can of worms! 😥

OMC made a change in their Big Twin flywheels around 1958-ish. The revised hub has a flange that the puller screws into. The one in the picture is the old style where the flywheel could be pulled off of the hub. Worse, they often broke loose.

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