Originally Posted by RC Dad

24 degrees is standard timing for stock motors but I usually set 19t or mods between 12 and 15 degrees advanced. Any more than that gets the motor hot too quickly and performance degrades when the brushes burn. You can tell if its too hot because the brushes turn blue and get brittle. They'll chip or chunk apart. They also scrape the comm badly at that point because the lubricant is burnt out of them.