Bad rectifier and lower oil question

[Morgan320i]

97 oceanrunner 200, how much lower unit oil and what brand do i need,
Also i think my rectifier, went out, my tachometer started going wack and jumping around, then it stopped charging, starts up perfect but shows no output voltage, same as battery,

 

[Chris1956]

The gearcase will take almost a quart of gear oil. I use a synthetic gear oil, but any marine grade gear oil for mechanical shift motors is OK.

Your motor may have a voltage regulator (versus just a rectifier). Before you replace it, check it for continuity from the VR to the tach. Sometimes they short to ground, which kills the tach reading. The VR should be behind the flywheel on top of the block. It will have a plastic cover over it.

 

[Morgan320i]

It has a rectifier/voltage regular, according to all the diagrams i have seen, i saw the plastic cover with a cdi box and the water cooled regulator/regulator below, checked all lines, part number is 0586271