It's not over the limit, but close to, assuming your measuring in degrees C.
I think for your CPU, the heatsink should be "Copper Backed"; is it?
You need to make sure you have fitted it around the right way as well. Although it's difficult not to, it is possible, and will result in a very poor contact with the core of the CPU. It can also result in chip damage to the core. The step on the heatsink, must fit over the raised end of the CPU socket. Quality thermal paste is a must, and the quality varies from supplier to supplier.
Providing you have a reasonable motherboard, the BIOS temperatures are close enough to be acceptable.
I am writing this reply on an XP 1900, and to give you some idea to go by, the current temperature is 46 C or 114 F, which ever you prefer!