IS IT WORTH THE EFFORT?

No, I haven't given up.  I've been busy on other things and nothing worth reporting has happened.  Well things have happened, but like everyone else reporting successes are more fun.  I can't wait to have one.

I have spent a lot of spare time researching unloading the torsion bar ready for engine removal.  I have had a lot of help from the Lambretta Club members especially "modelman093" who sent me pictures of his reassembly tool. 

Tool and collar

HOW IT WORKS
When reassembling the torsion bar link to the engine the hole in the link does not align with the holes in the engine.  
The link is positioned  between the two engine mount lugs. The tool is inserted from one side of the engine until the first shoulder buts up against the link . The off set pin on the tool is now engaged in the collar retaining the needle roller bearings.  The tool is rotated until the link and engine holes align.  The link pin is then driven through the assembly pushing the collar and tool out as it does so.  Neat?
I still think that's the easy bit to understand.  What I have been spending my time on is a tool to take the tension out of the torsion bar and thus protect the needle rollers.








To satisfy my need to come up with a great engineering solution I set about mocking up a tool.  I really went to town using wood rather than my usual cardboard, this was going to be good.  I had only just finished the first attempt when I thought of a better way.  This lead on to a third attempt, each one becoming more complex.

Marks 1, 2,and 3

MARK 1
The first one was intended to pull the top of the torsion bar arm forward reacting against the lower end of the arm.  A long leaver would have run forward below the rear apron mount.  I intended to  fit a bolt to the end of the leaver so that I could make fine adjustments.  
I discarded this design because it produced too much twist in the vertical section.

MARK 2
Similar to MK1 but this time the leaver runs towards the rear.  In this configuration it was possible to eliminate the twisting when under load.  I felt that I could make the forward reaction point sufficiently strong by adding bracing.
I discarded this design because it relied on the leaver at the rear being lifted and there was a possibility that it could turn the bike over.  Also fine adjustment might be diffiicullt.



MARK 3
I felt that a sort of small "G" clamp might be a better solution.  I could get the reaction where I wanted it and have control over the force applied.  I needed to apply the force between the engine and the top of the torsion arm.  My difficulty was to find somewhere on the engine where I could attach one end of the device.  I finally settled on flange surrounding the engine link pin.  This is some 5mm deep and providing I prevented the clamp slipping off I felt it would work.
 
At the end of this I asked myself did I really want to spend a couple of days making this tool when it appeared that it was possible to do the job with a large "G" clamp.