Holy Cow! Wait, that's India: Mad Cow! No, that doesn't cut it either. Yes, 10 degrees movement is a lot (five degrees of retard - half the slop in each direction)! Change it before it skips a tooth! Good call, Quenton.
Banshee is again correct, it's hard to just pick the parts and expect results, but I'll check my notes at work and see if there are any tips I can share. One thing to watch for, make sure your mechanical advance doesn't start until 1200 rpm, or you can get an unstable idle (surging when really bad). If you write down the number of degrees advance at every 500 rpm as you're playing with the springs and weights, you should be able to zero in on the right combination pretty quick. Don't be surprised if it takes 4 or 5 tries on the first one.