classic bike troubles

I bought a 1974 BMW R90/6. It wouldnt run. I'm hopeless with mechanical issues so I took it to the local dealer. They had it for a couple of weeks and called me to take it away; they couldn't get it to start either(!)I figured, it cant be that hard; it wasn't seized. Its basically half a volkswagen. I bought a workshop manual and learnt how the thing works. If it has spark, fuel and air it HAS to start, no? Learnt how to set the ignition timing. There is a little rubber grommet on the engine housing that you pull off and it exposes the fly-wheel. Timing marks are stamped on it. So, I set the points. Still wouldn't fire. Thought about it for a while and decided to pull the (new) sparkplugs out. Poked a stick in the hole and manually rotated the crankshaft until the piston was at top dead centre. Set the points accordingly and it fired up! Wo-hoo! The timing marks on the fly-wheel bore NO relation to the actual ignition point.Much later, a BMW-whisperer told me what was wrong. He said that the gearbox must have been out at some point and they had put the fly-wheel on in the wrong position. Later models had a key-way to prevent this. The dealer must have put the strobe on to set the points and when it didn't work, just gave up. Lesson for me was, have a go.....you might just figure it out. via /r/motorcycles https://www.reddit.com/r/motorcycles/comments/ajb6f9/classic_bike_troubles/?utm_source=ifttt