I have the cylinder head off my 05 R50. The head was rebuilt and ready to go back on.

When removing the head I did mark the timing chain/sprocket. Buuuuut there is a caveat. I was ignorant of Mini's lack of external crank timing marks. (WTF?) To place the cam alignment tool on the cam sprocket I rotated the crank. This was AFTER I removed the chain tensioner. I at least had the sense to only rotate clockwise knowing that I didn't want to rotate INTO a slack chain, if that makes sense. It rotated easily but I did hear the chain bunch and release on the tensioner side.
I have some confidence that the chain did/could not jump but that is not 100% confidence which is what one wants. I tried to lift the chain off the sprocket and make it skip but was unable so maybe it can't. I would really like to double check the timing but, as far as I can tell, this is not possible with removing the lower timing cover (ugh).

I welcome opinions on the above and also have these related question:

I have been careful not to move the crank after removing the cam sprocket. I want to clean the piston tops but I am not sure how to do this without positioning them at the top of stroke...
Can the R50 crunch valves if the timing is way out of whack?

Thanks
Rich

 

anyone, anyone?