I need some serious help? Tec question. I have a 1978 mercury 115hp and keep burning out the cdi switch box. I have replaced most all wires that looked bad installed a new cdi box, new cdi dist, checked for charging and min 12+ voltage at all times, the red/white wire on the switch box to 12 ign volts and good with key on, did replace the white wire in the harness, then white to white brown to brown and black to black to dist and made sure all connections are tight and secured against any vibration. I am on a second cdi box and both acted the same way, runs good in a tub, in the water doesn't idol well and both did not run well under power. Both acted the same way, ran for an hour then like someone turned off the key, no start after that, I have 12 volts to the cdi and no spark. I even ran a seperate ground from the cdi plate so no possible lack of ground. Both boxes showed signs of fluid leak from the seal on the box and one had oily fluid on the green coil wire right where it comes out of the box. I am under the impression that the boxes are getting hot causing fluid leaks and then failing. When I installed the second cdi, I had spark and I thought I had a bad box, but the same problem. Also to mention the cdi boxes and dist are new not used. I have been a mechanic for a long time and also worked on a lot of marine motors. I am wondering is there something that I am missing or could I have gotten two bad cdi boxes, I would think thats almost impossible. Thanks Buz
