I have fought with the ubiquitous grill regulators for years, sloppy, ill-regulated pieces of crap!
Last week I found these nifty little surplus, machined brass, Mapp regulators, on ebay for only $12. new in the box. It took a little tinkering but once installed I now have micro-meter adjustment that will take our unit from a fine line of flame to blast furnace temps ...and without those pesky push-to-turn safety devices too. I expect I could fire pottery in our barby now. These are far superior to the original.