hi, i have just got a new tacho, just a 120y standard one, for in my 120y. I have an L20B, when i used to have the A12, the tacho work fine, and was accurate, it moved smoothly. But now, ever since I got the L20B, it worked for a while (2 Weeks) and then just went spastic, like from 0 to 8000 back and forth. while it did work, it was still a bit wavery, not smooth like with the a12, sort of when back and forth by about 500 or 1000 rpm. My new one does this too, i would like to know if anyone has had this problem and how the hell to fix it. Thanks