RATE OF FEED
A common error of the newcomer to routing is to feed the router too slowly into the workpiece. This gives a poor cut and can easily cause scorching of the wood. Cutters require fresh wood to be presented to each blade as it meets the wood; if not, the cutter will rub instead of cutting and the wood will be burnt.
The practical guide to whether you’re proceeding at the correct rate of feed is that you should be producing perceptible cuttings and shavings, not smoke and scorch, or broken-off splinters.