There are many many many small business roaster builders in Mexico. Untill you post a photo I'll just guess what yours might be like. I've roasted with a number of Mexican machines and usually they are built solid,take an incredible amount of abuse, pretty low tech so it's easy to repair if anything wears out. Just keep it greased up and cleaned out and it might run forever. Always underpowered in the sense that the burners are primitive. You might be able to upgrade the burner pipe. Under load it if you want roasting time under 20 minutes. Usually just one fan for both roaster air flow and cooling tray. Easy to learn how to roast in, capable of great roasts once you get enough practice. I was planning to buy a 5K Macafe roaster from Veracruz. $3,500 brand new custom built with two fans and vent pipes, but the price of shipping it to Vancouver went up to about $4,000(!) so until I drive a truck there some day (very doubtful) I gave up on that plan.
In pretty well every Mexican roastery I've visited they overload the drum, set the gas on high, and do some other chores until the temp gage hits the number they want (30 minutes or more usually) then dump and cool. The overloaded cooling tray takes another 20 minutes to cool it enough to remove. Baked beans, flat taste. A few times I've used their roasters and, loading 25% less greens, done sweet, profiled roasts in 18 minutes. They think they're saving on gas with the bigger loads but I show them they're not. Next visit they are always doing it the way they did before, of course
