Originally Posted by squirrel_hunter

Your timing is out as you've used the wrong timing marks when removing the rear CCT.

The F and the R is for a clearance check not for removal (I've made this mistake as well).

Check in the manual (either Haynes or workshop) but the short version is front cylinder first, rotate to TDC and the F mark on the timing. Remove and replace the CCT. Now rotate 360 and the rear CCT can be removed and replaced.

For valve clearance check it is the same but after the front rotate 270 to the R mark and check.

I would suggest you check your timing. Take the valve covers off starting with the front and make sure that is aligned, I suspect this will be fine. Now to the rear where I would guess you're off. Ensure that the engine is at TDC. Take the CCT out align the cams and the chain. Replace the CCT. Rotate the engine twice and check alignment.

And now while you are in there do a valve clearance check.