Hi guys. I have been away from the bike for several weeks and have just started working on her again. I did the first 3 openers and closers and I am really pleased with the clearances that I now have. Now number 4 which just happens to be the least accessible (horizontal inlet). I took the opener shim off and tried to remove the closer but it would not move. I could get it to push down but could not get it to clear the groove in the valve where the retainer sits. Eventually I managed it with a bit of brute force and tons of ignorance. It appears that the retainer may have hammered the valve stem to give a small lip in the grove near the end of the valve. My dilemma is do I take the engine out of the frame and remove the head and clean the burr off the valve, or just replace the valve altogether, or do leave the engine where it is and try to get a file in and just aim to remove the burr is situ. Because of clearance this will undoubtedly be difficult. Help please, what would you do.

Working on other peoples engines, and at least once on my own, I have experienced this a few times. The lip is caused by an excessive closer clearance allowing the retainer rings to hammer against the valve groove hence creating a burr. Quite often the retainers are also broken.
My answer has been to use a piece of emery cloth to rub the burr away with the valve in situ. Access is difficult but fortunately not much rubbing is usually required to remove the burr so that the closer shim slides on and off easily.

Thank you Derek. It is always encouraging when you hear from someone who has had the same problem. I know access will be difficult but I am pleased that you succeeded in removing the burr with a bit of emery. I will definitely give this a go. As you say it can't be much material that needs to come off as I managed (eventually) to get the old closer shim off. I suppose if any valve clearance is going to be neglected by previous owners it would be this one, ie the least accessible.

It has to be worth a try and is much better than taking the engine out and the head off.

Definitely worth a go and incidentally, you don't need to remove the engine to take the cylinder heads off. The only hassle is having to drain the coolant.

Thanks again Derek. I had already drained the coolant when I took the radiator off to give me a bit more room to get at it.

5 minutes with a piece of fine grade emery and the closer shim slides on a treat. What was I worried about. A lot easier than taking the head off.

Good stuff Giscard, it's not so hard really. That's something else you've learned

All back together and the engine is running nicely

Good to hear that Giscard. Well done.