Hi all I've got a bit stuck with trying to tighten my chain on my nc30 .
I purchased one of the c spanners of eBay .
I've undone the 17mm bolt and I just can not seem to get the chain to tighten . What is the correct chain tension and how do I get it to turn sorry I've I sound dum but it's doing my head in now lol thanks for any replies mark

lifting the rear wheel up makes it eaisier to turn.

Correct chain tension is half inch play in the middle.

you hub might be sized, not common but it can happen.

try lifting the rear wheel off the ground first.

Sit bike on rear paddock stand, or Abba type stand.
Grit and corrosion can make the adjuster stiff to turn.
Remove pinch bolt and tap a wide blade tapered wedge [not a screw driver, a bolster chisel works well without marking S/A] into the slot in the S/A
Spray with WD 40 or similar and turn wheel in same direction whilst pulling on the adjusting spanner.
Try adjusting in either/both directions if still stiff, an extra tubular handle extension will improve leverage.

I set mine to 15 to 25mm [20mm prefered] up and down play in the tightest spot with the bike on its wheels or rear stand.
Tighten pinch bolt to 40ft/lbs.

If hub is very tight to turn then remove it and clean out the grit that go into the hollow section from the front near the rear shock, when time permits.