I have a Model E60ELCRE and I can't get the tach to work correctly. I've changed the tach and get the same results, WOT is'nt consistent. Sometimes it reads 4200-4400 and other times 4700-4900 with the same boat and water conditions. What I don't understand is sometimes when I throttle down the rpm's will actually increase. Will the rectifier cause this kind of problem or is it a work or not work kind of part. The setting on tach is set to 5 for a 10 pole motor which I think is correct for this motor. Need some advise on things to check, thanks.