2000 Mercury FourStroke 90 Voltage Regulator

[pcrussell50]

A Mercury OEM replacement voltage regulator for a 2000 Mercury 90 FOURSTROKE engine is listed as "unavailable" at parts websites. The same part is widely available from Yamaha at $275. Aftermarket voltage regulators are about $75.

Among aftermarket brands of voltage regulators for a 2000 Mercury 90 FOURSTROKE, what brand is preferred?


BACKSTORY ON VARIOUS TOPICS.
My 2000 Mercury 90 FOURSTROKE is the (in)famous carburetor engine, and for me has been working a treat. With the automatic start enrichment, it seems to operate indistinguishably from fuel injection. The powerhead is a the Yamaha F100 powerhead.

Late in 2021 on a boat outing enough insulation had cracked off of the voltage regulator wires that they began burning and smoking while underway. After figuring that out, I unplugged the regulator, turned off all the electrical customers and finished out the day uneventfully.

--Peter

[jimh]

Try CDI. Mercury OEM electrical parts were often made in Mexico.

[Vance's Revenge]

If you are positive the part from Yamaha will work. It is worth every penny to buy Yamaha factory parts. Especially electronic parts.

[jimh]

Like Vance implies, use caution if you buy the Yamaha part. While the power head may be the same, made by Yamaha and sold to Mercury to be painted black and branded a Mercury, the electrical systems on the two engine may not be identical.

You can generally identify Yamaha electrical connectors by their rather unusual appearance. They use connectors that are common in Japan but seldom seen in American-made products. Mercury-branded engines were usually fitted by Mercury with their own wiring harnesses so they could be connected to Mercury branded engine wiring devices like ignition key switches, alarms, gauges, engine safety shut-off switches, and so on.

From your comment about "unplugging" the voltage regulator, I infer the device must have an integral electrical harness with a connector. If the replacement part has a connector that matches the OEM part, then the replacement part is probably suitable, no matter who made it.

But do check with CDI, as they make many aftermarket replacement parts that are better than OEM, particularly for older Mercury engines.

Also read this discussion on the same topic in the archives:
https://www.continuouswave.com/ubb/Foru ... 02518.html

[pcrussell50]

Thanks guys. The Yamaha part will fit. As with the Yamaha carburetor parts, the regulator is part of the engine, not the rigging.

It was a good idea Jim, to check with CDI. But alas, they only have parts for Yamaha engine older than my my 2000 four-stroke-power-cycle version. I’ll be stuck with factory Yamaha on this one as you have convinced me to avoid the low cost options.

This is on my Alert17 (Special Services Montauk).

I do have a 1986 classic 13 SPORT with a featherweight Yamaha 40-HP two-stroke-power-cycle engine. CDI makes a power pack for that one. But I don’t need it yet as the original is still working well.

ASIDE:
Point of order: for years you and I have gone back and forth on this: You keep correcting me to “FOURSTROKE”. Yet my engine cover clearly says “FourStroke”. Per the third image down on this randomly googled web page: https://www.ohiogamefishing.com/threads/2000-mercury-50-four-stroke.313308/

-Peter

[jimh]

ASIDE:

For years you and I have gone back and forth on this: You keep correcting me to “FOURSTROKE”. Yet my engine cover clearly says “FourStroke”.

The use of FOURSTROKE indicates a model name, not a characteristic of the engine power-stroke arrangement. In some places Mercury uses initial capital letters followed by small-capital letters, a style known as "caps and small caps." You cannot recreate that in ASCII text. In some places they use italic caps and small caps. You can find many instances of this use with a image search for "Mercury FourStroke" images. Here is a random sample from such a search.

https://dd26fishing.com/products/mercur ... -75-90-115

See: https://en.wikipedia.org/wiki/Small_caps

The goal is not to replicate their logo, but to indicate that the designation is a model name. On the website model names are consistently given in all-caps, such as MONTAUK, OUTRAGE, REVENGE. Those words are model names, not places or emotions. The same with trade names like E-TEC, LOAD-RITE, E-Z-LOADER, HUMMINBIRD, and so on.

The graphic designer who made the decals for your engine was probably not following the corporate design department strategy.

I used to work for a company whose visual identity involved the number four. There was a specific hand-drawn "4" that was always used in any branding. In a similar manner, I used to work for a magazine whose magazine name was always shown on the cover in a hand-drawn font and used all-lower-case letters. There was no way to reproduce that typeface . All occurrence of it in product literature were just scaled versions of the original hand-drawn logo. The fascination with all-lower-case continues today, as we have a prominent marine electronics manufacturer called "em-trak"--all down case and odd spelling.

What's a fellow to do with all this?

Another problem: odd spellings often cause alerts to misspelled words. However, spell checking is usually not done on any words in ALL CAPS. This allows odd spellings to not be continually marked as misspellings.

[jimh]

I don't share VANCE's admiration for Yamaha electrical parts. On the twin 1976 Yamaha 70-HP engines I used to own, both stator coil assemblies failed and had to be replaced. Replacing the stator required removal of the flywheel. Removing the hold-down nut that retained the flywheel required a special wrench to grab onto the flywheel and use of an impact driver to loosen the nut. The available extra electrical power provided by the permanent magnet alternator in that engine was about 100-Watts, and the stator was very prone to overheating and failing.

I am surprised that CDI does not have a replacement part for a c.2000 Mercury engine voltage regulator. That must mean the voltage regulator in that engine is generally a reliable part. I suspect CDI has learned what parts to make for OEM replacement: the parts that most often go bad and are no longer in stock at the OEM. Also, if the voltage regulator is in a large aluminum heatsink assembly, it may not have been practical for CDI to create such an enclosure. Also, I bet inside the parts are all potted in some gel or resin, so you cannot open the assembly and just replace the internal components.

The good part of this is that today $275 is not what it used to be. The government keeps sending out checks to stimulate the economy, so you can just look at the $275 purchase as part of economic stimulation paid for by the government.

[pcrussell50]

I am surprised that CDI does not have a replacement part for a c.2000 Mercury engine voltage regulator.

Good point. So I just checked. And surprisingly, CDI does not.

I bought an immaculate used [voltage regulator for my c.2000 Mercury engine] from an auction websit. It is installed and working a treat.—Peter

[jimh]

[My Mercury engine] has been working a treat….[A used elecrical part] is installed and working a treat.

Buying used electrical parts is often a roll of the dice, to use an American phrase (meaning an uncertain outcome). In contrast, your twice-used phrase “working a treat” sounds very British.

[Jefecinco]

I find myself using "Britishisms" at times and chalk it up to marrying a Brit forty-five years ago. I consider myself to be bilingual.

[pcrussell50]

[My Mercury engine] has been working a treat….[A used elecrical part] is installed and working a treat.

Buying used electrical parts is often a roll of the dice, to use an American phrase (meaning an uncertain outcome). In contrast, your twice-used phrase “working a treat” sounds very British.

That’s a good laugh. I grew up in Australia. Came to America for university and stayed. In earlier times I might have been insulted, what with the shared heritages between Australians and Americans over having "escaped" Britain.

-Peter

[jimh]

ASIDE: many years ago I was involved in an eight-week-long project involving quite a large crew. One of the more important participants (“director” level) was from England. I was a working as the senior technician of a crew of two dozen technicians. One of them was from Australia. In a meeting with the Brit, we were running through the crew names, what they’d be doing, and so on. When I got to the fellow from Australia and mentioned where he was from, I was expecting an enthusiastic response from the Brit.

I was completely surprised by the Brit’s reaction. He said, dismissively, something like, “Oh, an Aussie. You know they refer to us as “Pommies”, don’t you?”

I was not familiar with the term Pommie , but it was clear it was a derisive expression. And that project was definitely not the happiest eight weeks in my career.

[pcrussell50]

I was not familiar with the term Pommie ….

A POME is a "Prisoner of Mother England". That is a term Australians use to refer to Brits who lack the drive for liberty and sense of adventure, to leave Great Britain.

I am an American citizen now, married to an American with two little American girls.

-Peter