Hi. I'm completely baffled. I'll preface this with that I am a very experienced mechanic, just not highly versed in mini.
A while back I burned an exhaust valve. Replaced all the valves and now, no start. I am absolutely positive the cams are in time, I've rechecked and rechecked. What am I missing? Is there a fuel priming issue I don't know of? What could I have possibly left unhooked that could cause an absolute no start? I'm beyond frustrated... Halp.

 

If all valves were replaced, do a compression check. Sometimes the valves will be too long and not close when on the cam flats.

Then there's ground connections that MUST be made --- the big one on the engine mount and the small one in front of the coils (for the R56).

Here's a BMW timing check procedure, maybe it will help --- https://bmwrepairguide.com/mini-r56-...er-all-models/

 

Think I've covered all that. Compression seems good, all grounds in place, great spark, rpm changes on scanner. The only code present is one for the thermostat control that I know I had before.

 

Did you change the timing chain as well? If not, then how much slack was in the chain? When I did mine, my timing was lined up spot on where I didn't think I had a problem. No start either. Once I got the new chain and compared them, I had so much slack in the original, no wonder it wouldn't start.

 

Gotta agree with Coz3z3, chain slack can cause your problem. That link I sent earlier isn't the best procedure, there are others. Let me know via NAM messaging if you want more procedures. Here's a quick way to measure chain slack ---