18hp Briggs Intek Twin Stator Regulator Charging problem - Melting multiple stators

[chuckles]

I have a Briggs Intek in my Bobcat ZTR. I noticed a burning smell last week during my first mow of the season, thought maybe something was on my belts so I cleaned and checked everything and went on my way. Didn't really smell it again so didn't worry. At the end of the mow I found out my battery was dead when I went to restart after blowing it off. Long story short after testing lots of things I found out my charging system wasn't working and discovered my stator wasn't throwing proper AC volts. Upon getting the flywheel off I found the stator was burnt black and melted. I had a spare on another engine so I replaced it, checked my AC volts and they were good. Put it all back together and started testing my charging system. Didn't look like I was getting the right charge at the battery when suddenly , prob 2 min into running, I burnt and melted the second stator. Now I have to figure out what is causing that and replace both the stator and whatever else is the issue. THis could get expensive quick since stators are about 70 dollars each. My gut is telling me the regulator/rectifier may be the issue but I cant find much info on testing it BESIDE checking the charge rate. I cant get to the point because I burnt up two stators. I always thought when a regulator went bad the system just stopped charging but now Im thinking maybe one could damage the other?

Could a bad regulator cause the stator to go bad, overheat/melt and burn up? I would be just fine with spending the money on a new regulator and stator if there is no chance in one of the other systems being the cause and thus me throwing away $100 on those two and still needing something else.

Could a bad coil cause a stator or regulator to go bad and burn up / melt? Is there anything else in the line on these charging systems that would do that to my stator? The fuses are good so I know that's not why it wasn't charging, had that happen a couple years ago and was easy fix. Is there some sort of computer or relays or cdi boxes or anything else in this system that might be the cause and cause this damage?

Im at a loss and when I spoke to briggs they said my carb may be dirty or my governor need adjusted???? That seems way off base to me with this issue but who knows perhaps there is a link.

 

[Boobala]

I have a Briggs Intek in my Bobcat ZTR. I noticed a burning smell last week during my first mow of the season, thought maybe something was on my belts so I cleaned and checked everything and went on my way. Didn't really smell it again so didn't worry. At the end of the mow I found out my battery was dead when I went to restart after blowing it off. Long story short after testing lots of things I found out my charging system wasn't working and discovered my stator wasn't throwing proper AC volts. Upon getting the flywheel off I found the stator was burnt black and melted. I had a spare on another engine so I replaced it, checked my AC volts and they were good. Put it all back together and started testing my charging system. Didn't look like I was getting the right charge at the battery when suddenly , prob 2 min into running, I burnt and melted the second stator. Now I have to figure out what is causing that and replace both the stator and whatever else is the issue. THis could get expensive quick since stators are about 70 dollars each. My gut is telling me the regulator/rectifier may be the issue but I cant find much info on testing it BESIDE checking the charge rate. I cant get to the point because I burnt up two stators. I always thought when a regulator went bad the system just stopped charging but now Im thinking maybe one could damage the other?

Could a bad regulator cause the stator to go bad, overheat/melt and burn up? I would be just fine with spending the money on a new regulator and stator if there is no chance in one of the other systems being the cause and thus me throwing away $100 on those two and still needing something else.

Could a bad coil cause a stator or regulator to go bad and burn up / melt? Is there anything else in the line on these charging systems that would do that to my stator? The fuses are good so I know that's not why it wasn't charging, had that happen a couple years ago and was easy fix. Is there some sort of computer or relays or cdi boxes or anything else in this system that might be the cause and cause this damage?

Im at a loss and when I spoke to briggs they said my carb may be dirty or my governor need adjusted???? That seems way off base to me with this issue but who knows perhaps there is a link.

I'm hoping the answers to your issue will be found here in these links ... the second link may be more helpful..

https://www.briggsandstratton.com/c...a/en_us/Files/FAQs/alternator_replacement.pdf

https://www.briggsandstratton.com/c...n_us/Files/FAQs/alternator_specifications.pdf

 

[bertsmobile1]

The usual culprit is some one fitting the battery backwards so the alternator is fighting the battery.
The other biggie is the output wire from the rectifrier direct shorting to ground as there is fuse on this system it just pumps out max current till something goes
So what was the last thing you did to the mower ?
What do the magnets look like ?
you can also get magnetic dust suck in there so the magnets + crud rubs on the stator and friction cooks it.

 

[chuckles]

Thanks for the links. Saw those earlier and read them. If I understand correctly there isn't anything else in that path but I'm no electrician. I'm just real confused that Briggs support told me the carb or governor might be the cause. Just doesn't make sense. Another buddy asked if the coils or cdi(I don't think there is one) is bad cause regulators usually just stop the charging system from working when they go bad not frying two stators. My gut is just telling me the regulator is the issue but don't know why...

As for the condition of the magnets and such, they were FILTHY when I pulled the flywheel off. Loaded with a dust, clippings, and what looked like oil residue / grime. I figured, at first, that's what cooked the original stator so I robbed one from my spare engine and installed. Think I took the regulator too and hooked it all up and got it running. Was showing 13.4 volts st battery but in my mind it should have been higher(probably a mistake in hindsight since the battery had been on trickle charge for 5 days and likely didn't need much charge from the regulated system). For this reason, if I recall correctly, I put the factory regulator back on to test charge and compare the two readings(it was 2am and I really should have just went to bed and finished later but I had victory in my grasp) and it wasn't 2 min later than I remember seeing 11.5 to 12 on my meter and then the smoke happened again. Second stator was toast. I tore it apart again, almost in tears but the more I thought about it laying bed last night and then today I started to remember that I was getting 13.4 on the other stator/regulator and the smoke happened the second time almost exactly the same time into running the engine as it did back when I mowed and I smelt it the first time. It really made me start to think it has to be the regulator that's doing it since I had no charge and have lost two stators on the same regulator in almost the same time frame from starting to toast but it ran ok and, no smoke, and I had a regulated charge on the seeming hood set from the parts engine I have

Problems is my theory has lots of holes and I just don't feel confident enough to throw 100 dollars at a new regulator and stator just to toast another one. If they were 20 bucks then sure but with 4 kids money is just too tight for that. Part of me says take to a shop so I only have to pay once but my pride won't let me not try and fix myself.

1. Could the coil packs cause stators to melt like my buddy said?
2. Does Briggs suggestions on the carb or governor make sense to anyone?
3. Does my idea of buying a new regulator and stator together make sense to anyone? Could the regulator have been the cause?

 

[Tinkerer200]

"1. Could the coil packs cause stators to melt like my buddy said?
2. Does Briggs suggestions on the carb or governor make sense to anyone?
3. Does my idea of buying a new regulator and stator together make sense to anyone? Could the regulator have been the cause?"

The first 2 of these options make no sense at all. They have no connection to the charging system. I would not do option 3 as there are lots of good used units out there at small repair shops. Large shops do not fool with parting out engines, if you are there at the right time, they might give you a complete blown engine. Note that these components are interchangeable between multiple B&S engines. I suspect the diode inside the regulator has failed permitting full battery voltage/amperage to flow back thru the stater burning it up.

One question, did you have the battery out and replace it backwards just before this started? If so, the regulator would be ruined instantly.

Walt Conner

 

[ILENGINE]

If you have a ohm meter. Put the red lead on each of the two wires on the regulator that connect to the stator. Put the black lead on the metal housing of the regulator and see if you have continuity. Wouldn't be the first regulator that I have found the AC shorted directly to ground.

Will result in the exact stator damage that you are experiencing.

 

[chuckles]

Thanks for the help, I didn't think it made sense either. I actually just starting thinking about used parts again tonight and using what appears to be a good regulator from the spare engine and finding a used stator and giving it a whirl. Shoot I got the whole mower with the spare engine for free so im sure I can find a used stator somewhere close or on craigslist and give it a shot. Best case it runs without issue (which proves my theory)worse case it goes out again and I know I have bigger issues to resolve. As for the mower and what I was doing.... Nothing out of the ordinary. I just started it for the first time of the season and was mowing grass when I smelt burning rubber (later I realized it was plastic I smelled) so I thought maybe something was rubbing my belts. I cleared the deck out real good, cut some nylon rope I had found that had gotten wrapped around the blade spindle and greased all the idle pulleys for good measure and went back to it. Never smelled anything again so at the time I figured I found the problem until I went to start again after I finished mowing and it was slow to crank. It sat all winter with a battery tender on it in the shop and I didn't change a thing. So not sure why the sudden issue.....

Some day I am going to repower the mower with a nicer commercial engine I think, just not sure what it would cost or how to approach it. The Bobcat ZTR is a real nice, heavy duty machine as far I can tell. Dad bought it 10 years ago before he passed away and gave good money for it but it just sat around a lot and got abused by random people who helped mom cut her grass over the years till she gave it to me. Needs a little TLC but mowed all last season fine just burns oil like crazy.

I am better you are right about the regular diode maybe going. Might try to test that like you said. I noticed just an hour ago when I was outside looking stuff over that the green plastic stuff molded in the center is lifted out of the metal case on one end, almost like it got hot or something. Maybe it was the stator that went bad and toasted it and then it toasted the replacement stator in return or something? Who knows..... think Im gonna look for some used parts tonight online and go from there.


One more question... how do you all torque the flywheel nut? Using a torque wrench and keeping engine from spinning while doing 150lbs is HARD. Would hitting it with an impact for 2-3 seconds be ok? Good enough or overkill?

 

[chuckles]

Here is a pic

 

[Tinkerer200]

Yeah, cooked. One way to hold the flywheel as recommended by B&S is with a strap wrench. Another is to feed a ft. or so of soft rope, nylon for instance, into the spark plug hole as the piston is coming up half way or more on the compression stroke. Be sure about that or you may damage a valve, bend it. Leave enough rope out to retrieve it of course. Impact wrench, no.

Walt Conner

 

[NorthBama]

there are many briggs engines in the bone yards, maybe you can find you a parts engine at a bone yard.