400FSE 2002 Starter

[Dirtbiker]

Hi All,
I have recently bought a 2002 400FSE that was being sold as having had a top end rebuild but owner had lost interest and just needed a few bits putting back together.
Looked like cheap fun and I enjoy trying to get broken things working!
First jobs were clutch cover and alternator cover needed refitting.
Got these on and poured some oil in and kicked her over.
Having done lots of reading on here figured I was never going to get it started on the kick and I wasn't disappointed - definitely wouldn't start. Made all the right noises though, strong compression and a strong spark.
Next was to try the starter and no luck here.
Not sure where to start with this one and was hoping for advice - have done quite a bit of reading already and not expecting it to start easily but the first problem I have is that it won't turn on the starter - sounds like it is not engaging.
With the alternator cover off the starter gears removed the starter motor appears to turn with purpose. However, when the gears are fitted and the cover screwed on the sound is not good. I have taken a couple of videos here:



https://www.flickr.com/photos/133652...etaken-friend/



https://www.flickr.com/photos/133652...etaken-friend/

And a photo of the gears - one looks 'modified' and perhaps I have assembled them incorrectly?



Thanks in advance for any advice and will hopefully get it running and make some new friends and get out on some adventures!

Cheers

Gareth