UPDATE: '91 Merc 90hp 30cyl overcharging problem

[jpollman]

Hi all,
this issue has been driving me nuts for a couple of weeks and I haven't been able to make any headway until today. This afternoon I finally decided to dive deeper into the problem and try to see what was wrong. Here's a brief overview of the problem....

I kept on getting a "high voltage" warning on my fish finder and checking with a voltmeter it was charging at as much as 16.8 volts. I figured that the regulator was bad so I replaced it. Afterward it didn't solve the problem. Today I pulled flywheel off and found that not long ago the previous owner had some work done on the motor. I know this because it's a '91 and on the pig tail from the stator there's a tag stating that it's a CDI Electronics stator and has a date of February 2002. Now the regulator I replaced was from CDI and it is the correct one for my engine. But on checking the part number with CDI I found that the stator that is in there now is a nine amp stator. I don't know if this mismatch of regulator/stator would cause the overcharging problem or not. It's Saturday evening so I can't get any tech help until Mondayl. I just tought I'd throw it out here and see what you out there think.

Thanks for any input you may have.

John

 

[jpollman]

Re: UPDATE: '91 Merc 90hp 30cyl overcharging problem

Oops, I screwed up. I left out some info and I guess I can't edit the post. The regulator I've got in there is supposed to be the correct one for this motor and is for a sixteen amp stator. But the stator that is in there is a nine amp.

I'm wondering if this mismatch in regulator/stator would cause the overcharging problem that I'm having.

Thanks so much for any input.

John

 

[andy6374]

Re: UPDATE: '91 Merc 90hp 30cyl overcharging problem

With a 9 amp stator you shouldn't need a regulator, a good deep cycle battery SHOULD act as the regulator.

At any rate I had a similiar problem with a CDI 9 amp stator in my 200hp. I ended getting CDI rect/reg # 194-5279...it worked

 

[jpollman]

Re: UPDATE: '91 Merc 90hp 30cyl overcharging problem

With a 9 amp stator you shouldn't need a regulator, a good deep cycle battery SHOULD act as the regulator.

At any rate I had a similiar problem with a CDI 9 amp stator in my 200hp. I ended getting CDI rect/reg # 194-5279...it worked

Thanks Andy!

That's the reg/rect. that I have. It's a CDI 194-5279 and I've had a heck of a time with overcharging. I've been running an Optima yellow top deep cycle/crank that I bought last summer and it's worked fine until now. CDI told me that Optimas don't work well with outboards so I pulled the Optima out and installed a brand new Delco Voyager BIG deep cycle that I bought this year for my trolling motor. Running on muffs in the driveway for about 15 minutes it worked fine and didn't charge over 13.6V. Just to check, I put the optima back in and it went back to 16.5V right away. That Voyager is HUGE and overkill for a crank battery so I borrowed another marine deep cycle/crank battery from my dad and put it in and the charge went back to about 15.7V again. It's just today that I discovered the error in the stator. I've only had the boat a little over a year and I know that the previous owner passed away a couple of years before I got it. Seeing that the date on the tag on the stator says Feb. 2002 that must mean that he had the motor worked on not long before he passed.

I'll see what CDI has to say on Monday.

Thanks for the info!

John

 

[Texasmark]

Re: UPDATE: '91 Merc 90hp 30cyl overcharging problem

Most regulators monitor voltage and current. Voltage to know when to stop, and current to know how much to pump.

I would think that if you were the other way around you would have this problem, not small stator, large regulator.

Putting the big battery on told you that you are unable to regulate your output at low curent levels. The big battery apparently allowed enough current to flow so that the regulator could work properly.

So with what's been said, looks like you have to marry the regulator to the generator (stator).

My '02 90 hp has a Red 16 amp stator and rectifier/regulator.
------------------------------
Just pulled out the service manual.

In talking about the 9 amp stator, it lists the current output from the stator at different rpm's. It also says that the 9 ampere was designed to put out nothing at idle and that the 9 ampere was designed for manual start engines. It says that the 9 is not designed to charge batteries (usually none with a manual start engine) rather to run lights only.

It goes on to say: "However, if a rectifier kit is installed on the engine to enable the stator to charge a battery......." and lists the currents that can be checked ranging from 0 at idle to 10 amperes at 4000 and above.

The other stators in the book (14 and 16 amperes) put out 4 and 5 amperes respectively at idle and progressively go up from there. Also the book says that if the output voltage is ever above 14.5 volts, replace the regulator/rectifier......referring to the 16 in particular; may apply to the the others too....probably does.

Looks like you need to get a "Rectifier Kit" for the 9 ampere stator or go and get a red 16 amp stator.

Mark

 

[jpollman]

Re: UPDATE: '91 Merc 90hp 30cyl overcharging problem

Thanks for the info Mark.

Actually I'm pretty sure that the stator is supposed to be a 16 amp. I'd rather have a 16 amp in there than the 9 amp. I too would have thought that the reverse situation would have caused more of a problem. (16A stator to a 9A regulator) I bought the regulator through boatfix.com and they show two different combinations of stator/regulator. In fact I think you're right. I think with the 9A stator, it's just a rectifier because it's listed at only about $25 or so. The regulator/rectifier I just bought was about $85.

I just got a factory service manual and it too says that if you ever get a voltage about 14.5 to replace the regulator/rectifier. Well I've done that because I thought it was bad but maybe the original wasn't really bad. Maybe it's just the mismatched combination of the 9A stator that's causing the problem. If it will solve the problem I'll be more than happy to drop $150 or so and just buy a new 16A stator and reinstall it. I just want to get on the water again and back to fishing! d

Thanks guys. Take care.

John

 

[cnccustom]

Re: UPDATE: '91 Merc 90hp 30cyl overcharging problem

http://www.optimabatteries.com/publish/optima/americas0/en/config/product_info/marine.html

they use them on outboards

 

[jpollman]

Re: UPDATE: '91 Merc 90hp 30cyl overcharging problem

http://www.optimabatteries.com/publish/optima/americas0/en/config/product_info/marine.html

they use them on outboards

Yeah I agree. The only thing is that I have a yellow top. It's not the blue top marine style optima. I think they're using the battery as a scapegoat for a cheap inferior product. (CDI that is) I've spent a LOT of time on the phone with boatfix.com and CDI about this problem. I've finally gotten a tech at CDI to agree that something is wrong and I'm waiting for a call back ffrom the warranty dept. at CDI. It looks like I'm probably going to be able to return the regulator that I bought that's not doing the job.
At this point I've tried three different batteries and I'm still getting up to 15.6V when the engine is running. I don't like this as I don't think that it should exceed 14.5V as the manual states. I don't know what is going to happen but if I end up having to replace the stator and regulator/rectifier with genuine Merc parts it's going to cost over $400.

I just find it hard to believe that the charging system on this outboard is that picky about which battery I'm using. I'll keep you posted if I find out what's causing the problem. I'm waiting for a call from someone local who says that he may have some ideas. He says that some of the early 90's Mercs had some quirky issues and mine may be one of them unfortunately.

John

 

[Texasmark]

Re: UPDATE: '91 Merc 90hp 30cyl overcharging problem

My 2c, the battery is just a scapegoat. I'm not some sort of dumbass. I built radar transmitters for the military for most of 36 years for a Fortune 500 company. I know a little about amps and watts and joules and recharging batteries and Kirchoff's law, and 1/2 CV squared and 1/2 L I squared, and all that stuff.:devil:

 

[tombocook]

Re: UPDATE: '91 Merc 90hp 30cyl overcharging problem

how do i get hold cdi?

 

[jpollman]

Re: UPDATE: '91 Merc 90hp 30cyl overcharging problem

how do i get hold cdi?

Hi Tom,

I called them at 1-800-467-3371

Listen to the menu and you should get a choice for technical assistance.

I finally think I have the return issue solved. CDI gave me a return authorization and I'm sending back the regulator I bought through boatfix.com.

I finally found a local (well an hour drive away) Merc servicing dealer that seems to know what the heck is going on with my motor. Apparently there have been some service bulletins on my motor. It turns out that I'm going to buy a "red stator kit" and a new regulator from Merc. It's gonna be about $400 which is tough to swallow right now. But not as tough as having a several thousand dollar boat sitting in the driveway that I can't use. Hopefully by the end of next week I'll have the parts and have her back together and seaworthy.

Thanks for all of the input folks!

Have a great day

John

 

[jpollman]

No Subject

No Subject

Well good and bad news.....

The good news is that after talking to a couple of different techs at CDI they've agreed that there is a problem with the regulator that I bought through boatfix.com. They gave me a return authorization number and I shipped it back today. Once they receive it they said that they'd credit boatfix and then I can get a credit through them. (that's who I bought it through)

Now the bad news....

The other day I ordered basically a complete new charging system through Merc. I'm getting a new 16A red stator kit and a new regulator. But it's going to total just shy of $400. ;(
That's really not in the budget now but I'll find the money somewhere. It doesn't make much sense to leave the boat sitting in the driveway all summer unused because of a $400 repair. Hopefully I'll have the parts by the middle of next week and I don't think it'll take me more than an hour or so to bet them installed and then the boat should be ready to hit the water next weekend.

Lookout you toothy critters, I'm coming to get you! d

Have a great and SAFE weekend all!

John