New to me Strada

[72degrees]

Aaargh. The worn flat Woodruff key won't come out. The seller was well aware of this problem it appears-hence the slipping flywheel.

I've drilled it gently and tapped it with a drill (gently!). I've used WD40 on it. It needs heart.

So, I've removed all the bits back to the crank and now need to remove the cam belt-which is very, very tight.

I suppose I should just use valve paste on the end of the crank and lap the flywheel in tight.

The seller has not responded.

I can't see lapping being successful for long. It used to work on magneto drive pinions years ago but they had a lot less mass whirling round.

The best stuff for getting stuck stuff loose is Plusgas in my experience. If you can get hold of some plasticine or play-doh, form a cup round the keyway/key and leave it all to soak in plenty of Plusgas at least overnight. Drain it off, try again. Then local heat. Then Plusgas and repeat several times. You may need to use more force with more suitable implements like a centre or narrow punch and a lump hammer, but beware sharp implements and be careful with your aim on each end of the key alternately.

A bit naughty not to tell you about the problem before sale.

[fatnfast]

The seller should hang his head in shame.

I have used grinding paste in the past with success, but it depends how bad the shaft is. Maybe a splodge of engineers blue would show better the contact points?

Putting heat on there would help, but may well ruin any seals. Is it rusted in place or just been physically mashed up?
Plus gas is one of the best to treat rusted parts, but if drilling etc hasn't worked I'm not sure it will help that much.
The other option is freezing it. Before the world became ozone friendly we used this option to shrink generator shafts with freon to aid bearing fitment.
Much fun was had freezing large rubber o-rings then wacking them with a hammer in an attempt to shatter them. The folly of youth I guess.

[huub]

get out a chisel, grind it to the right size , and hammer the key out.
do not attempt to drill or grind it out , you will probably damage the crankshaft
lapping with grinding paste works perfectly, but probably isnt needed..

[72degrees]

I bow to the voices of experience with regard to lapping, but doesn't the vestigial key make that tricky unless you flatten it completely first, to get a good degree of reciprocal rotation, if you see what I mean? Or perhaps the key literally flat already. It's a good way out of a 'gumption trap' but I'm sure the late Robert Pirsig RIP (Yesterday) would persevere for a bit longer yet. 'Shock and Unlock' freezing/penetrating spray works well (particularly for getting needle roller bearing outer races out of alloy suspension linkages) , but really needs heat first and materials with a greater differential expansion/contraction rate.

[Papa Lazarou]

I am concerned that heat may damage seals. I have ordered a miniature blow torch (the one I have won't give an exact enough flame). I'll need to get the cam belt off first but that's proving difficult. It is on very tightly.

I have tried freezing, with no success but could keep going.

I'm not going to drill, grind or use a Dremel to get it out.

I have drilled a small hole in the key so I can insert a self tapping screw to give me leverage (the key is nearly flat against the shaft).

The shaft looks to be in pretty good nick, so I may decide just to grind it with valve paste against the flywheel.

The flywheel has clearly been rotating on the shaft.

[Ming]

I would persevere with the penetrating oil first, a mixture of acetone and ATF works well, together with a well-fitting punch and patience.
The 250C2 I'm working on came with a stripped key, which came out after some effort. As for the cambelt being tight - you could always cut it off, a replacement can be got for a fiver or so.

[Papa Lazarou]

Excuse my ignorance but what's ATF?

Aha: https://www.engineeringforchange.org/ho ... ating-oil/

It seems cooking oil and acetone should be just as good.

[72degrees]

Excuse my ignorance but what's ATF?

Automatic Transmission Fluid.

Spark erosion might get the key out and there are mobile services - at a high cost I suspect.
Does the belt look new?
I'm with Ming. Cut it off if necessary, then you'll be certain it gets a new one.

You'll get there in the end!

[Papa Lazarou]

The belt is new.

[Ming]

Just took at a look at the 'for sale' section ad. Looks to have had a lot of work done and sold as a runner. Hopefully it's just this key and a slipped flywheel that's the problem with it. Even if it's a new belt, if it's tight it may be better to replace it. If it's stopping you from fixing the problem it definitely needs to come off IMO.
As for the penetrating fluid, any light oil is good with the acetone I believe. Perhaps not virgin cold pressed olive oil, though.

[Papa Lazarou]

Thanks. I'll replace the belt. It seems almost glued on!

Have now acquired the ingredients for the penetrating fluid and some plasticine.

[Papa Lazarou]

I have received contact from the seller, who has been very helpful.

[Haboola72]

I had the same problem with the crankshaft on my 501 camel rebuild. The woodruff key was almost sheared flat.
The woodruff key is only there to locate the flywheel on the crankshaft, it doesn't hold it on. The tapered faces of the crankshaft and flywheel, properly lapped and torqued, fix the flywheel firmly on the crankshaft.
After a long hour of alternate heating, freezing and worrying the battered thing with a keenly sharpened (on one side only) cold chisel and other implements, the key refused to yield.
Like you , I then drilled into the centre of the key to gain purchase, but this probably only served to push the sides of the key tighter against the slot.
Left with a small hole ( albeit in the right place ) in what was once the woodruff key, I popped a 3mm ball bearing in the hole with a dab of silicon and fitted the flywheel.
It worked well and probably would have been left alone had not the plain main bearing decided to give out 500 miles down the road...

Since then I 've split the cases and removed the crankshaft which made the business of replacing the key a little easier! A roller bearing conversion will follow...

[EVguru]

The purpose of the key is to line up the timing marks. You can carefully file down the key (it's softer than the crank) and set the rotor position manualy from TDC, or just ignore the alignment if you know your timimg is correct.

[72degrees]

The purpose of the key is to line up the timing marks. You can carefully file down the key (it's softer than the crank) and set the rotor position manualy from TDC, or just ignore the alignment if you know your timimg is correct.

Seems like the quickest fix if all else fails. I hadn't realised the keys were that soft. I'd still be inclined to double check the timing as it has been running so poorly. I've had the rotors off my various Morinis many times over the years and never come across a bad woodruff key or had a rotor slip. Seems odd at such a relatively low mileage for this machine. I guess I got lucky. I now feel compelled to check my TDC marks and valves yet again seeing as I pinched the barn find 250 rotor to go on a 350 that had experienced a pretty hard life judging by the state of the big ends.