johnson 50hp j50pleea timing

[fordwheeling250@yahoo.com]

I recently put a new timer base on my johnson 50hp j50pleea due to loss of spark. The directions said to time it after installation. I went step by step from the johnson service manual, and when it was finished the timing was way out at 5000rpm running down the lake. I shortened the linkage to advance the timing as much as possible and the timing got to 16btdc. I rechecked the timing a few days later and it was only at 8btdc. Is there something else that affects the timing? Does the power pack have anything to do with it? could i have gotten a bad cdi brand timer base? Thanks