I really feel like a bag of ducks (yes, you know what i mean) for not triple checking everything. One does a restore job on an engine, then lets it sit for a year (money, time) and then continues wich it is a dangerous thing. Literally. The flywheel nut was not even tightened well.
Things to be done now is:
Replace the tension sprocket, cam sprocket (just in case) and cam chain. Then, because I have to take the engine apart to flush it, I need a complete engine housing gasket set and also a new float chamber sprocket which bloated out of shape.
The crankshaft locking pin needs to be fixed up, the piston wall needs smoothing out and also the cylinder wall needs some sanding and polishing.
Lesson: Check, check and check again if you do not do an engine job in one go. If you have to pause, write things down. Catalogue what you are and have been doing.
More updates soon.