I bought an older evinrude last year and was told I have a 1978 140 horse evinrude. When I went to buy new ignition coils for a 1978 they were the wrong ones, but the 1977 ignition coils were the correct ones. Could someone clarify the correct model aand year that I have. Mod# 140843C ser# J0001381.I am not sure about the 8 in the serial # since there is a light scuff mark there. It may be a 3 or 6. thank you