using an external voltage regulator on Yamaha 9.9

A number of Yamaha 9.9 4 stroke hi thrust owners have added an external voltage regulator ... specifically a Flexcharge NC25A . I would also like to add a regulator that works.
Most problems people have is with over voltage after the batteries are fully charged. They add an "additional" regulator to the output of the engine. However, my problem is that I suspect the factory regulator gets hot and shuts down... mine just quits charging... I also suspect the factory regulator has ruined at least two batteries that were new..
I have run the existing engine output to my electrical panel and installed an ammeter. I can monitor voltage and amperage. What I would like to do is run an UNREGULATED electrical output from the engine using this cable lead that I have installed ... then I would be able to install a good regulator.
HOWEVER, the factory regulator is also a rectifier. (I was told a rather questionable quality half wave rectifier at that)...
I see that on the yamaha 9.9 electrical schematic of the engine there are two leads (green and green with a white stripe) coming into the engine regulator from the "Lighting coil" of the engine alternator. .. I have to assume these could be used to fit a bridge rectifier on the engine..?? But, there is also a third wire from a second coil on the engine from a coil also marked "lighting coil"....

I doubt anyone will read this thread or if they do will have gotten this far LOL ... but I am determined to fix the regulator problem I've had with this engine from day one. I assume that if I were to connect a full wave bridge rectifier that I could run the unregulated output to a separate Flexcharge regulator ...
If there is anyone who might 1) understand what I am trying to explain and 2) have some idea of how to connect an external voltage regulator AND rectifier, Please contact me ... [email protected]

All those words. Yet the most important are missing.

What is the model of the motor? There are over 10 different versions of a Yamaha four stroke 9.9 HP motor. Here in just the USA alone.

There are models with no lighting coils. There are models with lighting coils but no rectifier or rectifier/regulator. There are models with lighting coils but only a rectifier. There are models with lighting coils and a rectifier/regulator.

boscoe said:

All those words. Yet the most important are missing.

What is the model of the motor? There are over 10 different versions of a Yamaha four stroke 9.9 HP motor. Here in just the USA alone.

There are models with no lighting coils. There are models with lighting coils but no rectifier or rectifier/regulator. There are models with lighting coils but only a rectifier. There are models with lighting coils and a rectifier/regulator.

Click to expand...

about 330 hours on a T9.9EXHA sn 6G8X790779 the schematic for this engine shows three leads from two coils marked "lighting coils" running to the rectifier/regulator.
note ...
the issue I've had is that if I motor for a few hours the engine quits charging ... the autopillot runs the batteries down (I single hand my boat) and at some voltage the autopilot also shuts down... when I', motoring the batteries should of course get topped off .. so I'd like to fix this issue. I could modifybthe rectifier regulator if that was possible to get an unregulated current - I just found a used rectifier regulator from a 1994 yamaha 9.9 ,,, perhapsyou are saying that I can't interchange these ... but the part numbers for them are the same.. ... luckily most of the time I am sailing and the solar panel keeps the batt. up. But I do not run both the solar panel and the engine at the same time because of the batt. charging issues... sohave this motoring issue.

about 330 hours on a T9.9EXHA sn 6G8X790779 the schematic for this engine shows three leads from two coils marked "lighting coils" running to the rectifier/regulator.
note ...
the issue I've had is that if I motor for a few hours the engine quits charging ... the autopillot runs the batteries down (I single hand my boat) and at some voltage the autopilot also shuts down... when I', motoring the batteries should of course get topped off .. so I'd like to fix this issue. I could modifybthe rectifier regulator if that was possible to get an unregulated current - I just found a used rectifier regulator from a 1994 yamaha 9.9 ,,, perhapsyou are saying that I can't interchange these ... but the part numbers for them are the same.. ... luckily most of the time I am sailing and the solar panel keeps the batt. up. But I do not run both the solar panel and the engine at the same time because of the batt. charging issues... sohave this motoring issue.

Thanks for the information.

The T9.9EXHA uses a rectifier/regulator. Which should be controlling the voltage at no more than 15.5 volts or so I would suspect.

I think what you are experiencing is the fact that the autopilot, and other electronic equipment that you might have in use, are simply drawing more current than the motor is capable of providing. The motor is only capable of outputting 6 amps under best case conditions. The battery is supplying any additional current that is needed. After a while the battery has no more to give. Voltage drops. Equipment shuts down.

Other than installing more or bigger batteries, or both, I don't see a solution to your problem. The lighting coils are only so big and the magnets are only so strong. Consequently the electrical output from the lighting coils through the R/R is only so much. Not much if you will. Some with much bigger motors have the same problems as you do if and when their electrical power requirements exceed what the motor can provide.