Green coating melting from stator

[steveo32]

Ok I have the green coating from the stator melting down the engine from under the flywheel. How do I determine whether it is the stator or the recitifier. I have read numerous posts and that is how I found out that the recitifier is also a common reason for the green coating on the stator melting. I have no loss in power and no other signs that it is faulty. I have only had this boat and motor for a couple months, so it could of been replaced. I thought at first it was grease or something but now suspect its not from the posts I have read. I have a manual, so should I take the flywheel off and see if the green coating is melted or not before I buy anything. Also what kind of affects should I be seeing from the stator coating melting enging wise? I haven't had any problems starting besides bad gas that fouled the plugs. But it runs fine know with fresh gas and clean spark plugs. I took it out today and it doesn't appear that the greeen coating is dripping down anymore, but does feel a little tacky on the engine, I assuming this is from the heat of the engine. Thanks for the help.

 

[tashasdaddy]

Re: Green coating melting from stator

what motor do you have?

 

[steveo32]

Re: Green coating melting from stator

Sorry, it is a 1975 70hp Johnson.

 

[tashasdaddy]

Re: Green coating melting from stator

your recitfier is separate from the stator, melting is not a good sign.

 

[F_R]

Re: Green coating melting from stator

Does your alternator charge the battery? If it does, the rectifier is OK. Find out if it is charging by checking the voltage across the battery terminals with a voltmeter. Should be higher voltage while running than when stopped. I've never seen a green stator leak, but I suppose it is possible. The original black ones as used on the '73 models was notorious for leaking. The stator serves two functions, charging the battery and supplying 300 volts to the ignition system. If it is leaking, I would replace it rather than take a chance of paddleing home. By all means, test the rectifier before you do. You don't want to melt a new one.

 

[tashasdaddy]

Re: Green coating melting from stator

there are 2 threads for testing recitifiers here http://forums.iboats.com/forumdisplay.php?f=31

 

[Vic.S]

Re: Green coating melting from stator

testing rectifiers

But if you use a digital multimeter for testing the diodes in a rectifier use it on the diode test range not one of the ohms ranges. Meters vary and they do not necessarily work on the ohms ranges for testing diodes. Some will work, some will work on some of the ranges, some wont work at all.

 

[F_R]

Re: Green coating melting from stator

Amen, I have one of those that don't work at all. But my $9.95 Wal-Mart analog one does.

 

[Vic.S]

Re: Green coating melting from stator

yes the analogue ones work. I think the trouble is that the digital ones apply such a small voltage on the resistance scales that the diodes don't conduct in the forward direction so you get an infinite reading both ways leading you to the incorrect conclusion the the diodes are blown. It takes about 0.7volt to make a diode conduct.

 

[steveo32]

Re: Green coating melting from stator

Well I checked all of the wires as instructed in the posts, and everything seems fine. I ran it for a while and poked the plastic casing that appeared to at some point melted and it is fine and hard now. There may have been an electrical issue that had been fixed before I bought it. What affects should I look for from the engine if the stator is going bad. From the posts I have read, if the stator is bad the motor won't run.

 

[F_R]

Re: Green coating melting from stator

As I said, it serves two purposes, charging the battery and providing voltage to the ignition system. They are separate and independent circuits. Failure of one will cause the motor to be hard to start or won't start, and failure of the other will cause it to not charge your battery.

 

[steveo32]

Re: Green coating melting from stator

Alright thanks, if I see any of those signs I will get a new stator.

 

[steveo32]

Re: Green coating melting from stator

Ok, looks like I am going to replace Stator. I was out on the lake a couple of days ago and probably started and shut the motor 3 or 4 times. Well I was getting ready to leave, so I went to start the boat and nothing no turn over no nothing. So I remove the key and put it back in and still nothing. So I took the cover off the engine and startined checking some wires and a couple minutes later with the enginge cover off tried to start and fired right up. Got to the boat launch and shut it off again then started right up again. The Stator must be going bad.

So this leads me to my next question, I found a stor for $80 on ebay and will be buying shortly, yes it is used. But my main question is can I put the flywheel on without a torque wrench. Are auto stores don't let you rent them, I guess too many were broken or stolen. So what are the down sizes of not using a torque wrench. I am strong so I won't have a problem getting to 105# of torque.

 

[Joe Reeves]

Re: Green coating melting from stator

The flywheel nut must absolutely be torqued to 105 foot pounds. To not do so will result in a sheared flywheel key and damaged tapers of the flywheel and crankshaft...... something you do not want to happen!

On that model, having the stator crack and melt down is a very rare happening. It is usually caused by having a blown rectifier which causes the charging voltage to back up into the stator resulting in a extreme overheating problem of the stator.

(Small Rectifier Test)
(J. Reeves)

Remove the rectifier wires from the terminal block. Using a ohm meter, connect the black lead of the ohm meter to the rectifier base (ground), then one by one, connect the red lead of the ohm meter to the yellow, yellow/gray, then the red wire (some rectifiers may also have a fourth yellow/blue wire. If so connect to that also). Now, reverse the ohm meter leads and check those same wires again. You should get a reading in one direction, and none at all in the other direction.

Now, connect the black lead of the ohm meter to the red wire. One by one, connect the red lead of the ohm meter to the yellow, yellow/gray, and if present, the yellow/blue wire. Then reverse the leads, checking the wires again. Once more, you should get a reading in one direction and none in the other.

Note that the reading obtained from the red rectifier wire will be lower then what is obtained from the other wires.

Any deviation from the "Reading", "No Reading" as above indicates a faulty rectifier. Note that a rectifier will not tolerate reverse polarity. Simply touching the battery with the cables in the reverse order or hooking up a battery charger backwards will blow the diodes in the rectifier assy immediately.

 

[steveo32]

Re: Green coating melting from stator

Thanks, if I replace the Rectifier without replacing the stator will this hurt the rectifier? I plan on changing both out just because the motor is old and it will eventually need to be changed.

 

[F_R]

Re: Green coating melting from stator

Rectifiers don't go bad with age. It is nothing but four diodes. Diodes are usually blown by high voltage or high current. However, if it is bad you need to make an effort to find out why it blew. High voltages come from loose or dirty connections. High current comes from battery polarity reversal. Rare but possible loose connection--inside the battery itself. I've never heard of a stator causing it though. Now, I gotta say this, we once sold a brand new motor that kept blowing rectifiers and we never could find out why. Believe me, that motor was gone over with a fine tooth comb. Not only that, it was owned by an electronics repairman. I think he finally got p'd off and took it somewhere else so I'm still in the dark as to what was wrong with that thing. Prooves one thing though, I can't fix 'em all.

 

[steveo32]

Re: Green coating melting from stator

My guess is that the guy I bought it from probably hooked up the battery wrong, since the battery is only a year old and he had it for a year. Also I used a battery jump pack on it once, that may have blew the rectifier. But anyways, I plan on replacing the rectifier before the stator because It will be here before the stator, so will it hurt the rectifier if I run the new one with a stator that possibly has the charge side of the circuit that is bad. Or is that why the rectifier might be bad, because the stator is bad and sending to much volts through. Should I just wait and replace both at the same time?

 

[F_R]

Re: Green coating melting from stator

As I said, I have never seen a stator blow a rectifier. Without reading back through this long thread, have you done an ohms test on the stator? And there is the melted mystery also.

 

[Joe Reeves]

Re: Green coating melting from stator

The stator, melting down, is obviously faulty. If you look closely at the stator, you'll see that there are three portions of it that contain larger coils than all the rest. Those three coils pertain to the ignition system.

If the melt down condition is at any of those large coil locations, a voltage drop will exist pertaining to the voltage that is being applied to the powerpack. This will result in weak, erratic, and eventually no ignition.

The series of smaller coils pertain to the charging system. If a melt down exists at any of those areas, that of course is going to affect the charging system.

Bottom line.... It's not a good idea to run a engine with a known faulty component.

 

[steveo32]

Re: Green coating melting from stator

Well the melting came from the larger coils, which is odd because charging the battery is the problem that I have. So I guess the Rectifier is to blame for the battery not charging and the stator will eventually stop working. So now I wait until the parts get in. Oh also I found while checking wires that the yellow and grey wire was in the wrong slot, It was in the slot below where it should of been I don't recall if that is where the other yellow and grey wire is or where the yellow wire is. I verified with the wire diagram in my manual, so switched that over and it still started up fine. So that may have had something to do with the stator going bad and the rectifier. Unless that was done on purpose to bypass the rectifier or something.