Cm870 starts then shuts off,starts back up with a puff off white smoke and stays runn

[JimT]

Overhead is pretty easy. If you're just double checking prior work you could leave the nuts alone and just rotate the engine to each position, then use the feeler gauges to check for anything too tight or too loose. It won't be a perfectly accurate measurement, but you'd just be looking for large discrepancies anyway. Though, if you're in there doing 95% of the work already then the other 5% to loosen and tighten/torque the nuts really wouldn't hurt.

The first time I did my overhead I went through and measured everything before setting them properly. I found large discrepancies that were consistent across all the valves. It seems the prior mechanic (who I paid to do the job about a year prior) probably used the wrong feeler gauge. The last time I did the overhead I didn't bother measuring first, I just loosened everything and reset them. Roughly the same amount of work, but done quicker.