The stock fan turns on about 210 I believe. Mine runs 168-174 most days on the highway and can reach 200 in traffic on a warm day. As old as your bike is I would replace the sensors with the ones in the sticky.
My 2001 ST4 runs high 150's on the highway on cool days. warmer days it runs about 159 to low 160's on the highway. In the city it runs in the 160 to mid 170 range. But in in stop and go traffic it will climb as high as about 200. I can hear the fan coming on in the 190's, I think around 197.
Lostboy...maybe not applicable to your ST2...but my ST3 runs in the 160's when the ambient temp is above 50°. Runs in the 150's when it's cooler. I believe the fan is programmed to kick on at 220° (but not too sure about that) however I have LT's fan kit installed. I switch on the fan when I'm in traffic and the temps rise in to the upper 190's.
My ST4 runs 160's on most days on the road. In stop and go its 190's and in the city its 200 to 220. I have been through the coolant system. Flushed, checked the Tstat and the sensors all working correctly.