With a small 75W enalarger bulb these times don't seem very very long, but it depends hugely on the negative and whether you are printing full-frame or just a portion of course.

You could check the bulb to see if it is heavily blackened and almost about to blow. Also, if it is a low power bulb can the enlarger cope with a 150W or 200W bulb as a replacement? If you are using some sort of halogen colour-head then those times do seem long but, again, check the condition of the bulb envelope and filament.