** Athlon Slot-A 650@800mhz but no-go at 850 ** Help!

[daver343]

Alright, my Athy classic .18 650mhz is sailing along at 800mhz. 123*6.5 however
every time I go into my bios (Abit KA7-100 bios ver TY) and I can't the settings for the cpu to run at 850, when I reboot nothing comes on the screen and I have to clear the cmos to get booting. My system is as follows. btw my voltage at 800 is 1.65 and the default is 1.6v.
Abit KA7-100 bios ver TY
AMD Athlon 650@800 1.65v
256mb PC-133 ram
Seagate BII 15gig 7200rpm HD
Radeon 32mb DDR agp 4x disabled
SB-Live X-Gamer (non 5.1)
NIC For DSL (pci)
ATI TV-Wonder (pci)
4x4x24 HP Rewriter
8x Panasonic DVD
Im cooling the athlon with an Alpha heatsink/fan and 2 sunon fans. I also have 1 case fan and a slot fan cooling the radeon witch is at default 166/166.
I know this thing can do more than 800mhz! Please give ANY advice to get me sailin at 850 please. Every time I try and get 850 (no-go) I reset the cmos then bootup, and get it going again at 800. Then as son as I go into the bios and change the settin for fsb/pci to 103/134 and the fsb plus to 27 (I have no idea how that works) I save the changes then reboot and the computer dosn't post at all. At that point I have to clear the cmos and start over. PLEASE, ANYBODY!!
Thanks in advance. (My cache is aet to 2/5 at 800mhz. I can change it in the bios) =) thx

[Railskinner]

i think ya pretty high in the fsb,if ya wanna go higher ya might have to use a goldfinger device,by opening the case and attaching one to pcb, www.highspeedpc.com sells them,also i think after 850mhz ya have to set L2cache to 1/3 ^_^