90 hp ELPTO Regulator/Recitifer

[Grantspec]

I bought this boat a month and a half ago and the tach hasn't worked since I bought it indicating to me the Regulator/Rectifier (R/R) was on its way out. It finally completely fried itself in a plastic oozing almost electrical fire kind of way. The yellow leads from the stator were burned (prior to the R/R failing) so I replaced them and several of the other connections going to the R/R. I replaced the R/R with a CDI unit. The tach now works and it seems to be charging. Although I have made one observation: With my multimeter leads on the battery connection points at the motor the voltage varies wildly between 12 v and 18 v. At the battery it measures 13.XX volts at idle and jumps up with throttle input over 14 volts. Also, I popped the cowling after a 30 minute ride and the R/R was too hot to touch which was concerning.

My questions are as follows: Should I worry about the R/R being too hot to touch for more than a second or two? Also should I worry about the varying voltage at the motor side battery connections? Do any of these indicate stator issues?

There are no visible signs of the stator being burned or oozing from looking up under the flywheel (I haven't actually pulled the flywheel yet). The manual was not very clear about how to check the stator battery charging coils. I would like very much not to burn up another R/R at $130 each.

Thanks in advance for the advice!

 

[sam am I]

This one I got and it's norm up to say.....14.5'ish Volts

At the battery it measures 13.XX volts at idle and jumps up with throttle input over 14 volts.

But, I need a lil help on this one...

With my multimeter leads on the battery connection points at the motor

What does this ^^^ mean? The red wire bullet connectors just on the output side of reg? Or the battery side of starter solenoid? Could be caused by higher than normal series resistance in path to battery/loads. This may relate to overheating of reg/rec.

Perhaps a photo/more detailed idea of where exactly this measurement was taken?


And

too hot to touch

doesn't sound typically right, no!! Was the battery perhaps lil extra low on charge? Extra heavy load? Then maybe, the bridge rectifier(not so much the reg circuit itself, both internal tho) can get hot(but not burning hot usually) under heavy loads.


And

$130 each.

Is waaaaaaay too much, agreed!!

http://www.amazon.com/MERCURY-MARINE...8RG8HJGA0BYTVX

Next time eh? Get a emergency spare(or two) even and STILL save!! Ran two yrs solid now, running 3 batteries this yr, 2 last yr, spot on output reg w high/low load(output) and line(input) changes, run cool and tach is rock steady still!

 

[Grantspec]

Thanks for the advice. I had bought a 40 dollar R/R from eBay and it didn't work at all. I think it was defective as my tach was doing wierd stuff and it wasn't charging the battery at all. I'll pick one up from amazon though thanks for the heads up! The wierd multi meter readings I am getting are taken at the positive starter solenoid post and the negative starter solenoid post. Also taken between the positive starter solenoid post and where the negative battery cable attaches at the bottom of the starter. Perhaps it's picking up some noise somewhere? Like I said it was a smooth reading at the battery at what seemed like the correct voltage. What still baffles me is the very hot R/R. Doesn't seem like it will last that long at this rate. I even coated the back with heat sink compound and sanded away the paint behind the R/R for better heat conduction. Thanks again for your feedback!

 

[Grantspec]

Also I should note that I am running a single flooded starting battery and almost no electronics. No stereo. No fish finder. Nothing. The battery could have been a pinch low but it the boat had no issues starting and turned over quickly the day I observed the hot R/R.

 

[sam am I]

Thanks for the advice. I had bought a 40 dollar R/R from eBay and it didn't work at all. I think it was defective as my tach was doing wierd stuff and it wasn't charging the battery at all. I'll pick one up from amazon though thanks for the heads up! The wierd multi meter readings I am getting are taken at the positive starter solenoid post and the negative starter solenoid post. Also taken between the positive starter solenoid post and where the negative battery cable attaches at the bottom of the starter. Perhaps it's picking up some noise somewhere? Like I said it was a smooth reading at the battery at what seemed like the correct voltage. What still baffles me is the very hot R/R. Doesn't seem like it will last that long at this rate. I even coated the back with heat sink compound and sanded away the paint behind the R/R for better heat conduction. Thanks again for your feedback!

Yeah, go w the amazon's, 1 yr warranty as well so good stuff there.

So.......

The engine block bolt/batt neg. post on starter's mount and the solenoid neg. are electrically the same point, so should of been okay, but best go to block bolt/neg. battery post when in doubt(which you did).

But......both weird measurements taken from the solenoid's battery positive post and being the same results from different(physically, not electrically)spots , tells me the ground references are the same electrically.

Also makes me lean towards somethings wrong and your measurements are true. I'd say then, if my guess is right, the battery measurements were smooth because the battery is clamping at 14'ish volts. and some series resistance due to a crappy connection between where you got 18V and the batt post is allowing your reg to float up.

These type reg's can and will heat up as well w no/weak loads. It's how they're designed to work and could explain it as to the day it was too hot to touch. Combined w some series resistance it sounds like, it was very lightly loaded......

http://forums.iboats.com/forum/engin...regulator-temp

Double check/clean/inspect/tighten all positive and negative connections(battery and reg's neg. ring lugs, etc) for corrosion and cut those red and yellow wire bullets off(doesn't sound to be this current issue, but can become one, been there) and solder and heat shrink as reducing any and all series resistance to the battery and loads, it will help it run proper/cooler.

After you have soldered the wires together where the red wire bullet connectors were and before you heat shrink over the connection, place you meter's pos. lead at that connection and place you meter's neg. lead on the batteries pos. post then fire up the motor. turn on some loads such as lights/pump and rev it up. You should have less than 0.5'ish volts "drop" from the reg's output to the batt's pos. post.

If ya can/want, do above voltage "drop" test from the red wire bullets to the batt's pos. post. now to double check those weird readings and use this as a reference while trouble shooting/eliminating any significant drops.....GL

 

[Grantspec]

I will try the above things and see if it improves. Thanks! I am really leaning towards trying the newer MOSFET type R/R as they are supposed to be a lot more efficient/effective than the shunt type diode R/Rs the only thing holding me back is I would have to come up with a new tach signal source. I've read that a lot of the motorcycle guys are doing this swap with good success.

 

[sam am I]

Yup, mosfet choppers and the like are pretty cool and very efficient in this type of app., no doubt. Sorta analogous to the ole iron core linear's @ perhaps 50% efficient verse the nowadays mosfet driven 90%+ efficient switchers we have in almost every power supply we use down to our lectric dewalt's eh?

Funny ya mentioned those, I was working on a model of one of those not so long ago....Reducing loading the stator when less power is required instead of just making a hotter space heater will not only increase HP at those times, it'll improve fuel economy too! Not like save the earth from certain doom, but it'll add up eh? Gotta love those mosfet's!

Wouldn't fix your issue if ya have one as we suspect though, right?

At any rate........

I believe ya'll could just pull the tach sign off either stator's yel wires, I had a reg ripped apart(un-potted) around here somewhere, but think I pitched it...........doh!! Oh well, I'll put a scope on mine and come up w something, the tach output it's most likely jsut a half wave rec'd signal, perhaps amplitude limited.. Think with the older separate rec/reg, they'd just hooked the tach to the rec output I believe.

Pretty sure then in an adapter/work around, it'd take just that! It would just require then a single diode hung off either yel. wire. to half wave rectify(positive pulses only) the signal.

 

[Grantspec]

It seems like a win-win to go with the mosfet. I am surprised an after market marine parts supplier hasn't caught on to this and started to sell MOSFET units for these mercs. I still have my old fried R/R maybe I'll take it apart and try to see where they pull the signal from. If I figure something out I'll post it up here. I'll get a mosfet on order as well. Until then I need to figure out this potential issue I'm having.

 

[Texasmark]

Digital multimeters are susceptible to noise pickup due to their high input impedance. The fast rising high voltage used to fire the plugs radiates from the plug wires and lower spikes from the wiring harness in general. At 2000 rpms the output voltage should be about 14.5v on a charged battery.

A discharged battery, while still how enough to start your engine may be discharged to the point that it overpowered the regulator. Charging systems are made to keep things topped off. The regulator is heat sunk to the plate to which it mounts which helps to dissipate the internal heat. I use white thermal grease behind mine just for grins.

Mark