My 84-86 straight 6 90HP will not charge.

I did all the test the books says and I think my meter is wack.

My question is,, if the Rectifier is unhooked and the battery is on hooked will the Stator keep the engine running but not charge.

1. Boat will run with battery and Rectifier unhooked.
2. Tach does work correctly, and the Tach wire is coming of the Rectifier
3. I put a new Rectifier on
4. At 2500 rpms the red wire on the Rectifire only shows 12.7 Volts and at the battery also.

It has been a while since I worked on one of those but I thought that they had 2 sides to the stator. One was for charging and the other for running. You could have a bad stator as well. If you have not gone over to ask at www.screamandfly.com then I would. They have way more outboard guys there.

Outboard ignitions do not use the battery. They run off a charge coil in the stator. The stator also has winding for the charging system, this system creates ac voltage in which the rectifier regulator converts and controls 12 volts dc. The tach circuit is a tap off of the charging system and not the ignition system. So a tach signal going bad is a good indication of the charging system is failing. Since you have replaced the rectifier regulator it is most likely your stator, there are specific tests to troubleshoot it. That is why it can run with out a battery or charging system, really only need the battery to crank it over.

There is two different windings in the stator. Low and high speed. If voltage is dropping off after a certain rpm then your high speed side of your stator is probably bad.

Thanks for the replys

Yes there are two windings ,low speed and high speed but those are for the ignition not the charging system.

Your correct.
I was thinking charging for some reason.