I could not adjust the primary chain, so I took the cover of and found the plastic adjuster was broke, while I had it striped down I thought it was a good time to change the chain and tensioner. the chain was not broken but comparing it to the new one it was longer.
They are larger chain links and made of brass and 4.40mm at the narrowest and 9.40mm at the widest.
I can remember taking the two items off, I seem to think they were under a gasket but not sure.
Thanks for all the help and advice.