High voltage over 3500 rpms

[Carl]

I am resurrecting this thread again since I experienced similar problems again this year, but worse. He is my situation. Last year as noted earlier in this thread, I had high voltage and for the remainder of the season, I always turned on all the electric accessories (lights, radio, fish/depth finder, and GPS) which would lower the voltage a bit. I figured I would do the same this year. Fast forward 1 year - I replaced the rectifier which was evident when the Tach went to 0 at ignition and then not move when the engine was running.

I did a shakedown run on Saturday and noticed the voltage was pegged at 18 after 10 minutes of running at 3K rpms. Again this is with lights radio - etc all on. The voltage was around 13 for the first 10 minutes. The problem seems even worse this year. Could this be due to the new rectifier allowing more voltage to the battery? I need to fix this correctly this time.

The engine does not have a voltage regulator installed.

Any additional help and advice is appreciated.

Thanks

Engine info:

Mariner 150 HP
Model # 0A906046
Serial # 7150726


Carl