I had another look and even though the threads on the bolts look a bit flattened they tighten up just fine.
Think I might need to switch out the sprocket, it's a Gusset 3/16" thing with the appropriate chain and the chain is s bit shitty and new ones in that size don't seem too common.
Yeah you're definitely best going back to a standard 1/8" set-up if it's a bit worn out, you'll have trouble finding the parts and it's heavy. If you want a more heavy duty 1/8" chain then check out the KMC 510HX.
Cheers @bmxed.
I had another look and even though the threads on the bolts look a bit flattened they tighten up just fine.
Think I might need to switch out the sprocket, it's a Gusset 3/16" thing with the appropriate chain and the chain is s bit shitty and new ones in that size don't seem too common.