Modern Vespa

What did I do wrong.
Rebuilt this T5 motor because of a leaking clutch side seal. When I put the cases back together I put a bit of grease on the kickstart spring and on little kickstart gear.
Now I've installed the motor and the kickstart won't move unless the clutch is disengaged.
The trans will still shift into all the gears.
I guess I'll have to open up the motor again.

Since the kickstart works with the clutch disengaged, it's probably something related to the crank / piston. Can you rotate the flywheel??

You may be onto something SaFis, i went out tonight and I can rotate the flywheel with a ratchet and 19mm socket, but there is a lot of resistance at the top of its travel, almost as if the piston is making contact with something. I tried levering the kickstart as I used the ratchet and it moved just fine.
I did put new rings on the piston, but not sure that's what is causing the problem.
I'll pull the head and the cylinder tomorrow and hopefully all will be revealed.

I think i figured out the problem. I installed a new crank during the rebuild. I think it's possible the con-rod on the new crank is slightly longer than the old one. Maybe it's causing the piston to make contact with the head at the top of its travel.

I took off the head and everything freed up. I added a second cylinder gasket, (I had an old one) and put it all back together, and it started right up and runs well,
Except...the clutch (which I also rebuilt) won't completely disengage. The cable is adjusted fine, but I have a hard time shifting into 3rd and 4th gear.
I partially dropped the motor and the clutch looks like it didn't spring back, I m going to remove it and try to figure out what's wrong with it.

Tested the clutch on vise using a small socket as a plunger and the plates separated when I tightened the vise. So I guess the clutch is working.
Going to look at the parts diagram to make sure I'm not missing something.

Took out clutch and soaked the corks and plates, put it back in and the scooter shifts fine again. I had rebuilt the clutch 2 months ago and then wrapped it in an old shop rag, so maybe the plates dried out a bit and were sticking.