Checked my valve timing and it was about 10° off on the inlet and 8° off on the exhaust. I've followed the procedure to reset it and am having problems getting the large circlip back in place. The serrated plate does not seem to be engaging properly and lying flat. Anyone experienced this type of issue before? I'm a little nervous about trying to tighten it down using the two bolts to seat it, in case I'm missing something.

 

You should be using the tool to lock the cams in place, if you haven't already done so.
With the tool in place and if the serrated plate can't be lined up, I believe the plate can be turned around to allow the bolt holes to line up.
That, or the cam plate can be rotated 180 degrees to allow the bolt holes to line up.

It's been many years since a timed a Jag engine, so I'm posting this from memory, but I believe that's what the manual says.
At any rate, don't force anything, it is not necessary to do that.

 

The serrated adjuster can sometimes be a little awkward to seat, if it goes in slightly off square it can lock slightly out, try and get them dead square when you seat them, and they should pop in when they are aligned properly. Do not use the bolts to pull them in as this will possibly cause damage. You can give a slight tap with a small hammer, "but only slight", you should not need to force them in any way but sometimes if they have locked just off square a gentle tap to square them up will pop them in.

 

Take some tension off the timing chain so you can "jiggle" the sprockets a bit, then try again. Often you have to move it round 180 degrees to get it seated and the screw holes lined-up. I've done this job many times but never had any trouble.

 

Thanks for the great advice. TilleyJon you were spot on with your comment that the plate has to be absolutely square when you present it, the slightest offset seems to prevent the splines from engaging. There isn't a lot of room to work there but after a lot of trial and error eventually they came together with just finger pressure being required. Appreciate all the help thank you.