tyson snow

I'm a recent convert to bikes and have just bought a 2001 YZF 600 Thundercat. It runs well and the idle speed is at 1200-1300rpm as it should be, but the temp is always around 70'C. I would expect the running temp to be around 85'C, am I correct assuming this? The temp will raise to 100'C in traffic and the fan will then kick in, but when I'm generally riding the temp is always low. This is always the case, even when thrashing the engine. Has anyone else experienced this problem? I'm fairly hands on but don't want to go to the hassle of adjusting all the carbs, so any info or tips would be appreciated. Thanks