I have a 4510 counter circuit that is used as a tachometer, the problem is that it counts up way too fast, with one pass of the finger through the ir led and phototransistor it counts up by a 100, when the cable from the clock is disconnected from the irled it counts very fast, it also only counts in odd numbers on some and even on the others. the schematic of the circuit and the connection is as follows: