I finally got my tach working on my 1996 DT 140 carbed engine. After swapping tach, rectifier and checking the harness, I swapped the ECU and then the tach worked fine. I could do this as I have twin engines. Someone gave me an ECU off a blown up 1994 DT140 and it looks identical, has the exact harnesses, number of and colors of wires but the part number stamped on it is just one digit lower. I put it on and the motor cranked right up, idles great and throttles up nicely on the hose. The battery is charging and all gauges working. Am I good to go or am I going to damage something?

Rick