Look for ram multipliers. I use 1:1.66 on my msi board for am2+am3 cpus. That ratio put my ram at the correct fsb while overclocking the cpu from 200 to 240. I was only able to overclock by 20% and run stable. To go higher, you'll probably need a voltage increase, better heatsink, and possibly a stronger power supply. It's not worth the cost.
But here in my motherboard's box,it is written that its extreme overclocking professional series motherboard.
G31 = entry level chipset, not for overclocking.
MSI = crap full stop.
It's not quite that bad.
It is true that the G31/G41 chipsets are economy chipsets. Unless you get really lucky, you will have difficulty pushing the FSB freq past 360 MHz. That means that the CPU's (E8200 and Q9300 families) with a 333 MHz FSB freq are poor candidates for overclocking.
266 MHz chips work pretty well and 200 MHz chips (E5200 series) with their relatively high internal multiplier work really well.
Next stop should be a guide for your particular motherboard. Google is your friend. If you cannot find a guide for the MSI G31, look for a P335 or P45 guide. The P35/P45 BIOS should be similar.
Go through the guides. Then take your core voltage off Auto and set your memory voltage to factory recommended values. Change the System Memory Multiplier (or whatever your BIOS calls it) from AUTO to 2.00, 2.00B, or 2.00D - or whatever you need to do to set the Memory Frequency to twice the FSB. (I'm not familiar with the MSI BIOS.) Then when you increase the FSB, the memory clock will rise in in proportion with it. At an FSB of 266 MHz, your memory clock should be at 533 MHz.
One of my G'byte G41 systems has an E6500 (266 MHz X 11) in it. I had it running at 3.87 GHz (352X11). It was Prime95 stable for 24 hours, but it was on the ragged edge. The board wouldn't run at 353 MHz. The CPU runs at a little past 4 GHz on my old P35 board. It is quite happy, though, at 3.66 GHz (333X11) in the G41.