Top end reassembly issue

[GlennR]

I'm installing the 300cc piston kit in my Zongshen NC250 that is in my Pitster Pro LXR250f.

Everything "was" going fine until trying to reinstall the camshaft. The timing chain doesn't seem to be mating with the lower sprocket, which means the chain is too tight to get the left camshaft bearing up into place. I assumed that the timing chain would automatically mesh with the lower sprocket when I slipped it up onto the upper sprocket on the camshaft, but that didn't happen...

Does anybody here know what I'm dealing with & have any tips on getting it back together?

(I've reached the conclusion that repeating the same things over and over isn't going to work. :hmmmmm)

Thanks,