Flywheel welded to shaft, any tips on how to remove flywheel?

[cscent]

Hello all, I purchased a 91 bass boat with a Force 150 hp outboard motor.
I knew that due to the previous owners reversing the battery leads and frying the ignition converter box, it could be an easy fix which it was. The problem I encountered after wards was that the timing was completely off. It turns out that, for what ever reason, they had the flywheel welded to the shaft, the weld bead size is about 1/3rd the Radius, about 3/4".
The TDC mark on the flywheel is at 30 degrees BTDC with #1 piston at TDC.
My question is, does the trigger get the pulse from the large magneto ring attached to the flywheel (8 bolts) or the small ring at the center of the flywheel which sits inside the trigger?
If the large magneto ring is what creates the pulse for the trigger, can I reposition it so that TDC "0" mark on the flywheel lines up with the timing mark on the plate with piston at TDC?
The OEM service manual does not completely explain from where the trigger gets its pulse.

Thanks for feed your back.
cscent

 

[pnwboat]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

The trigger gets it's pulse signal from the small ring (magnets) on the flywheel that sit inside the trigger.

They probably welded the flywheel to the crank because it kept shearing off the keyway due to the keyway slot in the crank being damaged. Usually caused by not tightening the flywheel nut to the proper specs.

You may be able to use a die grinder with a carbide bit to grind the weld down to the point where you can remove the flywheel.

 

[cscent]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

Thanks for your reply. I guess I should find a machine shop parts supplier to get carbide tool bit to fit in between the shaft and the flywheel housing. I'm using a grinding bit made for sharpening chainsaw blades, very slow process.
Why they welded the flywheel 30 degrees off beats the s*^t out of me!
I've seen a long time ago an electric arc bit machine used like a drill bit in a power hammer drill motor but using arc to eat up the weld. I'll try tomorrow to find a small enough carbide tool that will fit in a die grinder.

Thanks
CSC

 

[notsunkyet]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

ive seen this done and it aint pretty! after you get the weld cut down and get the wheel off remember to buy a GOOD die for recutting the threads!!! the weld is going to be harder than the base steel so use alot of cutting fluid and even more patience!!! make sure the once the flywheel is off to clean the weld off the flywheel too. reindex and check the key slot for damamge. i have used a dremel to "resize a slot" (i found using mulitple cutting disks stacked ontop of one another works fairly well)to the next size bigger. Can be done but not fun...Check with john from md or frank amacorpa(sp?) they might have a lead on a newer good flywheel. also the key is not mild steel its hardened stuff hit up a machine shop for the good stuff.

 

[cscent]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

Well, after an hour of carefully grinding with a chainsaw sharpening bit, I managed grind away a little more than
1/16" of weld. Looks like it will take quite a few hours, maybe
days, to free the flywheel.
I'll post the results when it's off.

Thanks guys,
cscent

 

[cscent]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

No sooner did I post a reply to this thread, I searched for broken tap and drill extractor and found this unit on www.electroarc.com/compactportable.cfm

Like I said, years ago I seen one working and now I remember it was at a manufacturing company I worked at.
Probably cost thousands to buy, looks like it's back to grinding!

cscent

 

[pnwboat]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

Somebody probably was confused when they welded the flywheel on. 30 degrees advance is the correct setting for ignition timing, but not for positioning the flywheel on the crankshaft in relation to the pistons. The carbide bits cut through steel much easier compared to anything else.

 

[moparman]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

There is a process called air arc that uses a tungsten electrode with an air supply that is used on thick metal,once the metal to be removed is liquefied, the air trigger lets the air take over to slice through the metal to be removed. Is this the process your thinking of????

 

[cscent]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

The welding supplier suggested the same. But mentioned that you cant use lincoln 220 arc welder with the cabon electrode. It requires a lot more juice than what the lincoln as to offer and it needs to be DC current.
I went to a machine shop supplier and got a $12 carbide cone bit and it works a little better than the chainsaw stone I was using yesterday. Still, it will take for ever to grind down the weld. Taking this to a machine shop would cost me more that what I paid for the whole boat. Not to mention I had replaced two main electrical components costing over $650 which puts me in the max ball park cost. I'll just have to keep at it.

cscent

 

[wickware]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

Please post a picture if possibly to show the challenge toward suggestions. Such as:

1. My 4" grinder will eat a weld alive in no time if it fits w/o other damage.
2. My air die grinder will eat a weld in confined areas at a good speed.
3. Then comes my chain-saw sharpener for the delicate sharpening and etc..

Most Of All, Good Luck!!

 

[cscent]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

I'll try again tomorrow to take a good pic and post it.
I'm just about done designing a Portable EDM machine
to be mounted to a magnetic base.
All last week I done research on electrically eroding away the
weld. I will post that when I'm done putting it together.
Thanks
cscent

 

[moparman]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

There's always laser power,although it might be a little pricey....LOL

 

[Jasper8301]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

Sad to say that the weld penatration is probably going to be upwards of an 1/8" deep, and it'll take quite some time using a dremel with a carbide burr to grind it away. The only other option that I know of is taking the motor to a machine shop and placing the entire engine on a mill and hard milling the nut off which all in itself would be a real treat, sorry for your situation man that has got to suck....

 

[cscent]

Re: Flywheel welded to shaft, any tips on how to remove flywheel?

Thanks for all the feed back!
I found a hardware store that carries burrs.
I picked out a burr with a ball tip on it and the
sales guy suggested using cutting oil instead of
liquid wrench. Well, that certainly works good but
the cutter speed needs to be around 20,000 RPM
to cut efficiently. I'm going back to get a smaller
butt to clean up what the round tip did not pick up.
Looks like I'm home free from this point on.
What a headache this was. Now I have to get or make
a puller to thread into the flywheel to pull it off and
properly and hopefully the flywheel bore is not badly
damaged on the taper side.
My camera was not able to get a close up pic, when
it's off I'll take better pics at that point.

cscent