Rectifier

[bucket]

Is having ignition key in off to change out rectifier enough or do i left hot side of battery cable off. Merc 2.0 carb.

[VectorPat]

Disco the battery!!!!! That red wire on the rectifier is ALWAYS hot no matter where the key switch is..

[MTCM]

Always disconnect/remove all power when messing with the electricals, especially the ECU.

Always disconnect the Negative side of a battery first, then Positive. When reconnecting, install Positive lead first then the Negative.

[bucket]

OK, Guy,s thank,s alot. Have a nice Easter!!!!!!!!!

[WATERWINGS]

does that only apply to EFI motors?

[VectorPat]

Yes, All Motors..

[WATERWINGS]

So a mid '80s carb motor has fire to the rectifier when the switch is off?

[MTCM]

Dat's right....................

[rookieflyer]

Throw away the merc or sierra rectifier and put in a real one.

After looking at the way mine was made when it failed last year, then seeing how several other's were not handling the heat load, I replaced mine with a 25 Amp part mounted on a small aluminum heat sink. It cost less and works better. I even see a noticeable improvement in charging. It has been on there a year now with lots of hours and no problems.

[bucket]

Swapping out rectifier cause tach doesnt seem to want to go.

[rookieflyer]

It probably has one diode out of four burned out then. This is exactly what I mean. The stock parts are rated so closely to the normal operating conditions that the slightest bit of abnormality causes component failure. Only a good EE could design something so close to the edge. What crapola!

Then again, I also make my own tachs because I find most of the commercially available ones under $250 are junk too!

[Bill Rogers]

I agree with Rookieflyer - save your money. A 25A rectifier bridge is less than $3 and is much more durable. I just smear a bunch of heat sink compound on it and bolt it down in place of the old rectifier. You have to do a little custom wiring but it's well worth the effort.

Also agree with comment on EEs (I speak with experience):D

[bucket]

What the he$@# is a bridge rectifier????

[rookieflyer]

Bridge Rectifier is the real name for the part that gets stuck in a piece of aluminum surrounded with cheap epoxy that you buy for your outboard. It's basically 4 diodes in a bridge configuration. AC in two corners gives DC out the other two corners.
Here's a link to a little tutorial on the subject....

http://www.tpub.com/neets/book7/27c.htm

OK, so I guess links don't work that easily - you'll have to cut & paste.

All that's in the marine part are the 4 diodes in a mountable heat-sink with easy to use wiring terminals.

[rookieflyer]

Bill - I am an EE, but I refuse to design things that way....

[sho305]

And I paid 40 some bucks for that pos on my inline? Well, it works ok except it charges all the time and nobody seems to know how to limit it. Guess I need to learn about electronics now:rolleyes: It had lots of AC, and no DC charge in the positive. Voltage stayed the same DC from rest to running. Anyway, on my inline you can just pull the harness plug on the motor to disconnect it all. On my Force I had to take every single wire off the power block to remove the motor.

Too bad you guys could not sell some of that stuff. How come nobody has a tack to read off a crank/flywheel? Or a pickup to mount that would run a car tach? Like I am going to spend $100 for this chryco motor special tach. I don't get that. Surely you can run a tach off one plug wire/coil and tach any motor. I bought a $50 digital clamp on tach, but you can't get a mountable one. I don't get it. I searched the net for hours and that was all I found except the expensive slow reading mini tachs for PWCs.

[baddjonny]

How are you voltage regulating it?? always felt the same way stock parts are a rippoff I would think you would need a scr or triac to regulate it espc the 40 amp alt ??? or are you just letting the alt fly would worrie about too much voltage. but for a quick fix I'm all for the three buck bridge years ago someone made a schematic for a solid state regulator for the old chrysler mech regs
mabye someone can do the same for a merc I cant see it costing more than 5 or ten bucks to build.

jon b

[rookieflyer]

I have an entire product line in development that includes tachometers that can be triggered any way you want. Your point is well taken, and I have been working this project for about a year now. There are beta test units in the field now that are doing rather well. No doubt they will be advertised here first.

I have not been in such a rush to complete all the units because the economy is sooo bad, and the *experts* say that this is the worst possible time to release new products. We keep plugging away because inpart I disagree with them.

I think performance boaters are tired of paying too much for technology and would welcome new designs at reasonable prices...

Do you agree?:cool:

[sho305]

There are not too many things you can't find a reasonable deal on for under say $1k on the net. I thought I was stepping back to 1950 when I tried to find a tach! Heck, I'd put a tach on my lawn mower for fun....:D Can't belive there is no market.

My old '73 inline 1500 Merc has no voltage regulator. I don't know what amps it is. It runs the water out of the battery and I have to fill it all the time, besides it pukes every two years. Someone said leave the lights on all the time...:rolleyes: It has the single stator, no high/low. Clymer tells nothing about specs like weight, amps, etc.

I was told the same thing about power protection on computers. A couple of 15 cent parts on the wires coming in would make a power supply surge protected, yet they do not put them in.:confused: Still do not know why it takes 100s of seconds for my computer to start at 1.7GHz, and a millisecond for a calculator to start...

[Superdave]

The old small square rectifier for the 9amp & 16amp systems did not use a regulator, but the battery usually needed a couple of good charges during the season. When Merc came out with the 40amp system it put out enough amperage to require a regulator, hence the newer & larger, regulated, rectifier. Then there's that "water cooled" regulator. I went to Radio Shack and bought a rectifier/regulator for about $6.00. Works great.
Dave

[rookieflyer]

The method used to generate power on O/B's is a particularly noisy one - even making large electrical spkies from time to time. The inexpensive soultion of using a rectifier with higher ratings works well on the older low capacity charging systems, but the 40A system with the regulator is a bit more serious. Truly regulating 12V @ 40A does take more than a couple of parts and some quick thought. My guess is that a Radio Shack regulator stopped regulating shortly after installing it - I don't believe any of theirs are rated for more than a few amps. Also, Radio shack parts often are parts that don't meet spec for commercial sales, so while they are OK for home hobbyists, don't trust 'em.
I would check for hidden problems that may lead to long term damage....

[bucket]

My head can't take anymore today!!!!!!!!!!!!!! No just BS ing . Worked in power plant 30 yrs , still dont have all those electrical term's . Keep posting i might learn today

[Bill Rogers]

Rookieflyer, I'm an EE too, that's why I said I speak from experience - I've sure done some dumbass things in my time!:rolleyes:

The cheap bridge is an option only for the 9 and 16 amp systems that use the little square 3-post rectifier. I think that's the type of system bucket's 2.0 has.

Here's a good picture:

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Product_ID=1167&CATID=41

Put the yellow leads from the stator on the terminals marked "AC", ground the "-" terminal, and put the hot-all-the-time red lead on the "+" terminal. The gray tach lead can go on either "AC" terminal. It's a good cheap fix for the older charging systems.

[Superdave]

a 16 amp system. Yes, it still works. Disconnected the red wire nad with motor running at 2K rpm putting out 14.5 volts @ 3 amps. Plenty to keep a battery charged unless you run radios, gps, depth finders, fishing lights, running lights and etc. And, yes, the 40 amp system does require more thought. as far as Radio Shack parts, any port in a storm, but as you can see still working after 5 years.
Dave

[Bill Rogers]

Dave, I'm glad to know it works. I've seen those before, but like Rookieflyer said, it has to operate in a very hostile environment. My guess is that it wouldn't last, but you never really know until you try it. Thanks for the heads-up.

I've given the regulation issue a lot of thought over the years. I have a dandy little regulator circuit that I used on aircraft to run 12v accessories on 24v, but I never tried it on outboards. It became a packaging issue, especially with clamshell cowls - there just ain't much room in there!

I've reached the conclusion that un-regulated 9 and 16 amp systems ares fine as long as you select the right battery. I've had trouble like sho305 has had with batteries spilling their guts all the time. A high-quality large valve-regulated battery is the key. The group 29 Delco Voyager is a good example. It will handle unregulated charging systems without complaint.

Good discussion guys!

[sho305]

Yes, great thread!

I had the Delco marine starting battery from Sams, the only one they have here. Had to water it every month of weekend use. I may checkout radioshack, but are you saying one could use an external regualtor from an auto alternator? They are much higher amps. I might not be running it this year, so no rush now but I plan on using it in the future. In fact, I had to buy one for my '67 Chriscraft ford alternator....maybe $35?, don't remember. Pretty sure that was not a generator. I tested the Merc with the new square rectifier, and ran 12.5 off, 14@900rpm idle, up to 16v@4000rpm! It is propped for 5700-5900rpm...

On the Merc you can get a tach reasonable as I have, but I am hosed on the chryco force and my lawnmower, a 20hp onan twin:D

I never had water boil out of that delco visibly. Once it did fly out and land in its side:eek: And the big car battery before it died too.

[BRENT GILL]

Guys , I have 1 question. The factory rectifier is a component
designed at 15 amps. When you install one designed at 25 that is like removing a 15amp fuse and installing a 25.

In most cases when you lose your rectifier there is a stator problem, or maybe the battery or charger was hooked up wrong , or something that caused the rectifier to go out.

Most of the time the stator is shorting internally creating a
heat load on the rectifier.

I've seen motors 5 , 10 , or even 15 years old that have never had them changed.

Don't forget about the design of the wiring!
But I'm all for you guys coming up with new designs!


Get them on the market asap. Thats how you can bring the prices down on some of this stuff.

[sho305]

Not sure what happened to mine. It appeared to be original and was rectangle shaped. From '73 and who knows what use, it did not work. I checked the specs on the alternator/stator and it checked good. Showed good even AC readings. Run two years on the new rectifier so far and all is well except the overcharging. Not much on the boat to draw current now, but maybe more later.

My '67 had one of these black boxes on it, and now has an electronic one about half the size I got at an auto place. http://www.americanpony.com/store.mv?c=Regulator

[Bill Rogers]

Automotive regulators work by varying the field current (excitation) - which varies the strength of the magnetic field about the rotor. These are of no value on outboards.

On most outboards, the magnetic field intensity is fixed (can't change the strength of the magnets in the flywheel). So the only way to regulate the output is to dissipate the extra power in the form of heat. That's why regulators became water cooled as the capacity went up to 35 and 40 amps.

Mercury only stayed with the water cooled regulators a few years. The later design is actually 2 separate 20 amp systems in parallel. At 20 amps, the regulators don't have to be water-cooled. BTW, if you have this type of system and don't really need 40 amps of capacity (many applications with carbureted engines don't), do yourself a favor and disconnect 1 of the regulators. Your stator will thank you and you'll actually pick up a few revs on top.

We're starting seeing some belt-driven automotive-style alternators on some of the newer outboards. This is a smart move in my opinion because now they can vary the field current to control output. This is much more efficient. It's better to not generate the extra power in the first place, rather than having to kill it on the output side.

Sho305, if your Delco battery has a way to add water it's not a Voyager. The Voyager is a sealed valve-regulated battery. In my experience, the group 29 size will handle the output of unregulated systems without any trouble. 16 volts will not hurt it for a few hours at a time. I know the owner's manuals tell you to only use conventional batteries with unregulated systems - and keep a close eye on the electrolyte level. But I've been using big sealed batteries on unregulated systems for many years with no trouble.

Brent, you make a good point about the 25A bridge being a bigger "fuse". All you have to do to fry a rectifier is connect the battery cables up backwards for just a fraction of a second! It's a good idea to add an inline fuse on the output side of the rectifier. It's cheap insurance.

[Bill Rogers]

Sho305, are you familiar with these tachs:

http://www.tinytach.com/origgas.html

I've never messed around with them, but they might be worth looking at - especially for your Onan application.

Maybe Rookieflyer will have something on the market soon?

[bucket]

On v6 stator with high -low side's are all 6 cylinders in at all rpm's or motor has to hit higher rpm's for high side stator to work????????

[BRENT GILL]

You should get a reading off the high side all the time but it should increase as the rpm's go higher.

[rookieflyer]

What motors use this kind of "split" stator?

[Bill Rogers]

All 3,4, and 6 cylinder engines with ADI (alernator-driven ignition) have separate high-speed and low-speed stator windings. The V6 and L6 have 2 of each. I believe the first year for ADI was 1976.

[sho305]

I have seen the little tachs, and they are neat. Might get one some day; but I just figure I might as well be gazing in bliss at a big analog tach swinging around if I am going to have one:D The curse of a gearhead?:eek:

So you are saying whatever comes out of a rectifier is drag on the motor, and if you disconnect it it will not be drag? If so than there is no way to regulate it that way, by limiting the current or switching? Maybe a micro NOS switch on the throttle running a relay to cut the power at wot...maybe not so good if you hold it there alot I suppose.

Maybe 8 years ago I was hanging with a local Polaris dealer. They had an 800 Indy they raced in drags. Had only a huge LCD tach on the bars with numbers an inch high. Never seen another one and can't find it on the net. Would be nice in a boat. They were doing test runs on the grass and I could see the numbers for about the first 30 yards if I was in the right spot:D Just about 11k that day.:cool:

[Bill Rogers]

Rectifiers by themselves don't put any load on the engine. Sho305, you're 1500XS system is unregulated (rectifier only) and should put out 16 volts (or more) at higher rpm. There's nothing wrong with that as long as you have a battery that can handle it.

My comment about putting a drag on the engine applies to regulators only. The regulator has to reduce output after it's generated. It would be better not to generate the higher-than-necessary voltage in the first place, but that's not an option because of fixed excitation (permanent magnets in the flywheel).
So the regulator has to reduce voltage by either shunting a portion of the output to ground (early systems) or by placing a variable impedance in series with the output current (later systems).

Either way, if the system is lightlly loaded, power is wasted and unnecessary load is put on the engine. The '92-up 40 amp systems with dual regulators give you the option of disconnecting one of the regulators which will result in slighly less loss - plus you get a spare regulator for free.

[sho305]

I see, thanks for the info. I'll have to see who has voyagers around here when I go to run it again.

[Bill Rogers]

By the way, I didn't come here to promote Delco Voyager batteries. A local parts houses sells them and that's all I've been using for a long time.

[rookieflyer]

Here's an early proto of our 1" tall Digital tach in high-bright LED.
I have tested this in all daylight conditions at all times of day, even with different sunglasses - and it's always clearly visible. An overseas LED manufacturer is making even brighter displays for me, which should be ready in about a week or so. I also have an LCD version in the works.

With the LCD tachs & speedos I can't get three digits to fit into a standard round for some dash panels with recesses around the cutouts. I'm not sure what to dod abot that. Likewise, I wonder if folks would want rectangular or square faces....

Perhaps it's time to use the S&F poll feature...

[sho305]

I have had good luck with the Delcos other than this overcharging on the Merc. Used them in other boats, cars ok. Also the cheaper Champions they sell at sams. Had a Ford battery puke after 3.5 years, and it took the dealer a half hour to find out how to pro-rate it. Was about half price, but they wanted more to renew the warranty:rolleyes: I had to buy it as the car had a goofy size I could not find.


Tach-Now those are some big numbers! It would be great IMHO to have a gimble that mounted in a round hole, then you could adjust the display to aim at you better. Even 20 deg of movement, but that would be hard to make. I would not care if the display was above the dash(and aim-able), but some might not like the looks. They are so thin anyway. I would rather the casing were a minimal size to encase the actual display on a panel type(not round in-dash).

The big problem I have is few OB hulls have a good dash you can see in front of you. I'd rather have it above the dash in my boat where I can see it and the water both.

[sho305]

Research-
Here is the one I saw on a sled, Avenger: http://www.racepak.com/ProdFrame.html a flat panel design.

A plain cheap tach like this would be great: http://www.racepak.com/F2-D1.html just make it adjust to spark per revolution, maybe a max rpm memory or redline indicator. Note how it mounts to a round hole, but is bigger than the hole. If I had $$ this would be it. Still would be nice to tilt it a little, suppose a bezel could, but maybe it is so big it doesn't need to. Looks like they start at $314...but they have memory and egt features I don't need...yet.

Here is a cheap one for cars only, duh. But very small: http://www.jcwhitney.com/product.jhtml?CATID=4574&BQ=jcw2 $46

Some other Avengers, note the price of serious racing/data recording: http://www.choppercity.com/inst.cfm

Bet you could not read this in the sun: http://www.kortz.com.au/tacho.htm

[rookieflyer]

Tach-Now those are some big numbers!
That's 1" tall in a 3 3/8 hole.

>It would be great IMHO to have a gimble that mounted in a >round hole, then you could adjust the display to aim at you >better. Even 20 deg of movement, but that would be hard to >make. I would not care if the display was above the dash, but >some might not like the looks. They are so thin anyway. I would >rather the casing were a minimal size to encase the actual >display.

With a display this large and bright, why would a rotating mount be needed? Educate me please...

Also, how many boats have dash panels with recessed gauge holes?

[sho305]

In my flat dash, it is below and to the side of me on the same plane as the steering wheel almost. Something like this tach http://www.racepak.com/F2-D1.html would still be nice to angle it towards me up and over. Maybe I would be better off to use a panel type tach, or a gauge pod on top of the dash. Kinda like looking from my computer screen to the spacebar...don't like it when wakes are rolling at me. Even if I am ducking behind the windshield it is hard to read them.

My 17' Checkmate needs some TLC, and I was trimmed out WOT and looking at the speedo & tach at the far end of the lake alone. Hit two wakes that came together from a 20' trihull pontoon with a 150hp and three tubes behind it. Got some fantastic air, but had to look back and see if the inline was still there:eek: :eek: Battery flew out of two tight bungies and in a box, other stuff flew, seat bolts tore out...ooops. Bow went way up in the air too. I even had hit the gas again on the landing to soften the blow, but it landed on the transom. So is my quest for more readable gauges to eliminate unwanted air time. With the evident rot in this hull, I am surprised something did not break. Trimmed down this plain vee does not notice wakes.

[Bill Rogers]

So is my quest for more readable gauges to eliminate unwanted air time.

That's a very good reason to have readable gauges! :D LOL :D

Rookieflyer - looks like you're doing some interesting things. Nice work!

[sho305]

I got the prop out of the water a couple times that day, then I rammed this huge wake in the back corner of the lake. It was too late to slow or trim down when I saw it. I was trying to avoid that until it had a new transom. Thought I was Mr Offshore for a bit there:)

[rookieflyer]

for the compliment. This has taken longer than I expected, mostly because the economy has taken a chunk out of business, so I have had to pay attention to things that pay the bills more than I expected to. On top of that, my Dad has been very ill and I was asked by the family to take responsibility for his medical care, treatments, decisions, etc... , and now I am told he's not going to be around very long, so much of my spare time is being directed toward him. Somehow, I am determined to get this gauge line finished. I look forward to having them all daisy-chained from one gauge to the other and using the data aquisition feature for tune & trim.
My boat will never be able to take advantage of all the features like some of the 100+ guys will, but I still love it when kids walk by the dock and ooooh & aaaah at the protos in the dash...
I'm even thinking that transparent fronts that let the printed circuit boards show might be a good thing...


Anyway, if they let me I intend to post a poll here shortly so as to have community help in some of the final design decisions. Then I'll be looking for beta testers...but keep that one quiet - I can't give 100 units away!!!

[sho305]

Hey that is way cool you can do that! Best of luck. I would be making all kinds of stuff like that if I was into that field. Good luck with the family too.

[gaineso]

My '86 Tower also is unregulated. Motor starts so easily that my Wally-Werld battery is fully charged fairly quickly. Real advantage of a fishin' boat. I have a continuos duty solenoid wired through the ignition switch and a toggle switch to parallel my 2 batteries.

When my volt meter starts to get over 15, i flip the switch and it brings it back down to 14. Keeps the trolling battery up better. I run all accesories on the trolling battery. Don't want anything on the cranker.

Been doing it this way since I got the boat new in '87 and seems to work great.

Sure could get interested in some of these new gauge systems if prices are reasonable.

[Bill Rogers]

I do the same sort of thing with a dual battery switch, but it would be a lot more convenient to have a switch on the dash. Plus I run the risk of leaving them paralleled after I shut down. I assume your solenoid drops out when you switch off the ignition?
Good idea ...

[sho305]

I was going to use one of those trailer isolators, that basicly only lets the current go one way to charge another battery. I never got two batteries in the boat though. Used to use them on the second car battery that ran the stereo amps.

[gaineso]

Bill, that's why I'm pulling power to the solenoid actuation circuit from the ignition. Turn the key off and it disconnects.

Plus, as is posted in another thread, those battery switches may momentarily disconnect both batteries when switching. That can do some damage. The way mine is, the cranking battery is always connected, just add or subtract the TM battery from the circuit. A lot less danger from spikes and stuff.

[Bill Rogers]

I like your design Gaineso.

The problem with isolators is the fixed 0.6v drop - takes away precious capacity from low-output systems.

[sho305]

.6v loss? I guess it is a good thing I have some relays laying around. Good idea Gaineso.

[Bill Rogers]

A battery isolator is nothing but a couple of silicon rectifier diodes in a heat sink filled with epoxy. Each diode has 0.6v drop across it.

Sho305 (Mr. Offshore:D ), looks like we're both going to be using Gaineso's design - hope he doesn't charge us royalties!;)

[gaineso]

Wish I could figure out how to post a wiring diagram. Posting it's not the problem, just not sure I can figure out how to draw it.

BTW I'll expect $5.00 a month royalty on my design ;) :) :o :mad: :p

[sho305]

I assume you ran a lead from the key/ignition to power the relay up, then ran the hot or ground connecting the #2 battery thru the big side of the relay? The only problem would be if the starter battery got low, and it drew a lot of current over the relay and the relay was too small. My relays are about 30amp I have laying around here. I could use two if needed, unless there is a source that is not hot while cranking? Never checked it, but the actual ignition must be.

$5 a month? Good thing our season is shorter up here;) :p :)

Offshore- I ran with the big block/deep vee crowd running lake Michigan for a while. It was fun, but I got tired of having to go there every weekend. Was not quite expecting air time on my little lake in that 17' vee. Lot easier to get out of the water in the little boats:) and wait until I pad it, no wonder tunnels are so popular here...:eek:

[sho305]

Here is a dumb diagram, of course all the grounds have to go back to the neg battery on a boat. I suppose you could get the ignition hot off the motor as well as the key- maybe better the motor wiring than key.

[gaineso]

sho305, that looks about right except I've got a toggle switch in the line between the ignition switch and the solenoid. That way I can turn it on and off as I want. And I don't have to worry about not turning it off. It goes off with the ignition.

The solenoid I'm using is supposed to be rated for 150 amps intermitent, 30 amps continuos, so it should be able to carry starter load if it has to.

[Bill Rogers]

I like your artwork Sho305:D

Thanks guys!

[sho305]

How about this, if it will post this time. I use the paint program that comes with windows. If you open a JPG with it, it will then save as a jpg so it is a small file. Easy for simple stuff.

150 imtermitant should work fine, I'll look and see if mine are rated. Likely batt. #1 never gets low with this anyway.:cool:

[gaineso]

Looks good.

May have to split my royalties with you.:D

[sho305]

I accept cash, check, money order, beer, boats, cars, etc....

:D

[what200]

Bill - you mentioned the water cooled rectifier.

Well I got one and it's fried. Unfortunately this one appears to only be available through the Mercury executive retirement catalog.

Are these a single 40 amp rectifier?

Could I use the 2 radio shack rects to replace it? How much cooling do these require? I'd rather just put the blown one back on to cover the hole in the exhaust plate but maybe I should fabricate an aluminum plate to cover the hole??

[what200]

otherside

[Bill Rogers]

"Mercury executive retirement catalog" LOL That's so true!

Yes, it's a single 40A rectifier and regulator. It's the regulator part that needs the water-cooling more so than the rectifier part. You would be converting to a 40A unregulated system by using 2-25A bridges in parallel.

I've never done that before - the voltage may be way too high. But if your motor is an EFI, there may be enough load to keep the voltage under control. A good battery can take 16 to 16.5 volts for a couple of hours with no problem, but I would guess it would be higher than that with your stator, even with EFI.

I have converted one of the later 40A system with 2 regs to a single unregulated 20A system and it works great (both regs were bad). I left 1 of the stator outputs open and put a 25A bridge on the other. I just smeared a bunch of heatsink compound on the bridge and bolted it down to the same plate where the old regs were. It's a carb motor, but it has an electric fuel pump and other accys to help keep the voltage under control.

Another option might be to change over to a 16 amp unregulated system. For what the water cooled regulators cost you could buy a 16A stator, a used flywheel, and have money left over. The cheap 25A bridges work great on those systems.

[rookieflyer]

They are often manufacturer's rejects sold and repackaged by radio shack. Just had another bad experience with their junk.

Try www. digikey.com or mouser.com for 40A or larger bridge rectifiers. You can either mount your choice of part on as big of a chunk of aluminum that you can fit, or I will be glad to help you size a proper heat sink if you know the size of the load on the circuit.
Either way, you can get great results...

[what200]

It's on a 2.0L carb motor around 87ish

Actually It's been fried for a while but my tach still worked until recently so I'd just charge up and bring spare battery. My only loads are starting, trim pump, and fuel pump.

I've heard these water cooled jobs fetch 200+.

I don't know if this is a conclusive test but my volt meter showed 19 volts AC from the stator wires at 1200 rpm, so I guess that would be a bit much.

RFlyer- I tried those links and didn't see a high current one but there were more choices than I could click. Sounds like I need a regulator to be mounted on the plate too.

The weird thing is I wouldn't have figured a 2 liter carb motor to have a 40 amp system, but this thing is a bit of a bastard merc. What's the difference between a 40amp flywheel and a 16 amp one?

[Bill Rogers]

is more like $400 for the water-cooled unit. Ouch!

I think all '89-'91 models had 40A water-cooled systems.

Yep, I'd be worried about high voltage with no more load than that. You really do need a regulator if you stay with your 40A system.

The 40A flywheels are bigger and heavier, have twice as many magnets etc. (If I say anymore about flywheels I'm afraid Dave S will strangle me, so I'll stop right there :D :D )

[gaineso]

Another link for parts. You'll have to do a lot of searching and clicking.

http://www.partsexpress.com

[what200]

I'm starting to think the cheapest way to fix my boat would be unbolt the Merc in the middle of lake, paddle back, and mount my Jap motor....

so would it work to put on a 25amp bridge rect and mount a voltage reg on the cooling plate too. Is it possible to use two rectifiers with the stator I have?

How do you tell the two flywheels apart? It is possible somebody put a 16A system on and didn't want to change the divider plate so they left the H2O rect. This motor is an absolute mutt.