Stator..charging and hypochondria

[KIC]

So... I am trying to decide if I want to continue reading threads about problems you guys have with YOUR bike(s). Seems that when I read about your problems, my Lil 89 brunette hypochondriac decides to catch whatever disease your bike have caught.

 

Seems like my latest may have to do with the stator. Been reading a little about some of you upgrading and repairing yours, and all of a sudden my bike has started acting a little weird.

 

At idle my charging gauge sits right at the bottom of the 12. Once I start riding, it moves up to the 13 range and stays up there. At a light (stopped/idle) back to the top of the 12 and then will slowly drop down to the bottom of the 12 if I have the brake on, and will stay in the top, to the middle of the 12.

 

All this seemed to happen after I disconnected the front anti-dives. The battery seems to be holding up OK and is only a little more than a year old.

 

Thought about switching batteries with the 87 which is newer just to rule out a battery issue.

 

So, does this sound like a stator going out ? I wish that brunette pig would quit catching everybody else's ailments...

[Flyinfool]

Ohhh do I have a nice package of gremlins just about all rounded up to send your way.......

 

No one up here will let me give them back......

 

 

 

The dash voltage gauge is not real accurate, Get a digital voltmeter on there.

[BOO]

Sounds like it's working about right. Like Jeff said the gauge is not real accurate.

The stators don't tend to get weak and then quit charging. They just quit charging.

I think you are fine.

BOO

[KIC]

I have a couple of new volt ohm meters ( thanks Harbor Freight !) I am going to buy a couple of alligator ( or maybe crocodile) clips so I can clip on the ends and mount the meter while riding. I'll check it out this weekend. I also will be checking the stator plug as described below:

 

 

 

I was given these instructions too:

 

Using a digital Volt Ohm meter.

 

Find the large white plug, near the fuel pump. Has 3 large white wires going thru it.

 

Pull the plug out for easy access.

 

Open the plug, and check for damaged, or burnt pins, If OK, re-connect the plug.

 

With Engine running, and a Third hand to help !!

 

Stick the Red lead into each of the 3 wires of the plug, ONE AT A TIME, and connect Black lead of meter to a GOOD Ground.

 

Now Select AC (( Not DC, but AC on the meter ))

 

With engine running, ( have helper work the throttle ) you should read an AC voltage on each of the three wires.

 

The voltage should VARY, from about 5 to 15 Volts, AC as the engine RPM changes, ( caused by your helper )

 

The ACTUAL Voltage is not important, but what is important, is that ALL three Phase's of the Alternator OUTPUT, is " About the Same Voltage "

 

 

OK----------- IF -------- the AC on ONE, of the Three Phases, is "" Substantially Lower "" then the other two,

--- Then your Stator is Failing !!!!

 

DO not be temped to use the RESISTANCE check method given in the Service Manuel, to Test, your Stator. !!!!!!!!!!!!

 

I did this test on KNOWN Bad Stator, and it checked OK, per the Resistance check,

BUt the voltage output of that PHASE, was below 2 Volts AC, the other two phase's checked about 7 to 9 Volts, AC at 2000 RPM.

 

From what you said in your posting, I think your stator is failing, OR---- your large WHITE PLUG, in the Three Phase Cable, has burnt or damaged Pins !!!

 

Open , and Check the Large Plug First !!!

Edited July 12, 2013 by KIC

[MiCarl]

You don't need to read the voltage while riding, the charging system does not care if the wheels are turning. The tests can be done in the driveway.

 

With the motorcycle revved to 3,000 RPM you should see 14v or more at the battery. Rev it up higher voltage should not exceed 15. If it passes those tests the charging system works properly and there is no need to test the individual components.

[Flyinfool]

I have a couple of new volt ohm meters ( thanks Harbor Freight !) I am going to buy a couple of alligator ( or maybe crocodile) clips so I can clip on the ends and mount the meter while riding. I'll check it out this weekend. I also will be checking the stator plug as described below:

 

 

 

GeorgeS sent me these instructions:

 

Using a digital Volt Ohm meter.

 

Find the large white plug, near the fuel pump. Has 3 large white wires going thru it.

 

Pull the plug out for easy access.

 

Open the plug, and check for damaged, or burnt pins, If OK, re-connect the plug.

 

With Engine running, and a Third hand to help !!

 

Stick the Red lead into each of the 3 wires of the plug, ONE AT A TIME, and connect Black lead of meter to a GOOD Ground.

 

Now Select AC (( Not DC, but AC on the meter ))

 

With engine running, ( have helper work the throttle ) you should read an AC voltage on each of the three wires.

 

The voltage should VARY, from about 5 to 15 Volts, AC as the engine RPM changes, ( caused by your helper )

 

The ACTUAL Voltage is not important, but what is important, is that ALL three Phase's of the Alternator OUTPUT, is " About the Same Voltage "

 

 

OK----------- IF -------- the AC on ONE, of the Three Phases, is "" Substantially Lower "" then the other two,

--- Then your Stator is Failing !!!!

 

DO not be temped to use the RESISTANCE check method given in the Service Manuel, to Test, your Stator. !!!!!!!!!!!!

 

I did this test on KNOWN Bad Stator, and it checked OK, per the Resistance check,

BUt the voltage output of that PHASE, was below 2 Volts AC, the other two phase's checked about 7 to 9 Volts, AC at 2000 RPM.

 

From what you said in your posting, I think your stator is failing, OR---- your large WHITE PLUG, in the Three Phase Cable, has burnt or damaged Pins !!!

 

Open , and Check the Large Plug First !!!

 

I am not sure if this is a good test for the stator since you are still taking the measurement through the RR. I think a bad RR could have an effect on the readings done this way.

 

The normal test is to do as above but to have the stator unplugged and test each combination of wires, ie 1-2 2-3 1-3. you will read much higher voltages, have your meter set on a scale to read at least 100 volts AC. Depending on RPM you will see anywhere from 25 to 90 volts AC. (Be careful, this voltage level can be dangerous) As mentioned the actual numbers are not critical, what is critical is that they all be very close to the same.

 

The resistance check is a good check IF you have a good enough meter to see very small changes in a very low resistance. Resistance tests are done with the bike NOT running. Most inexpensive meters will not see the change unless it is a complete failure. I know my cheap HF meter will not see it but my nice Amprobe will see it with no problem. But even with a cheap meter, you can do a resistance check to from each of the stator wires to ground, if you get anything other than infinity, the stator has a grounded winding and is bad.

[jeff1]

I had something similar happen. I had replaced the stator and R/R with the kit that I purchased from Earl (Skydoc) late last summer. Earlier this year I had vaiations in the voltmeter similar to what you are describing along with intermittant momentary stalling of the engine. The tachometer also tended to flicker. The problem ended up being a very slightly loose positive battery cable. The bike cranked fine when cold, cranked a little hard when hot. Because of the hard cranking when hot I thought perhaps the battery was failing, a load test revealed it was fine.

How I finally found the problem was at one point I stopped for gas and when I went to leave I hit the starter button and everthing went dead. I moved the wiring by the battery and got the bike started went home and proceded to clean and tighten the battery post bolts with a wrench vs. a phillips screwdriver. 1000 miles after I did this everthing is operating normally. I have no one to blame for this but me as I put the battery in. I feel a little stupid that this even happened as I know better. I was close to contacting Earl and tell him that the stator I purchased was failing, I would have been completly wrong. Moral, pay attention to the details.

Good luck,

Jeff

[GeorgeS]

No, your not takeing the AC readings thru the R/R unit.

 

Find the white plug, directly out of the stator. With plug connected, and engine running, stick Red meter lead into each of the 3 wires at the big white plug, and

read the AC voltage to ground .

 

What you are looking for, is that the AC is about the same on each of the Three Phase's output from the Stator.

The voltage will vary with engine RPM changes.

 

If the lower section of stator is Fried, then one of the three will be much lower then the other two !!

 

However, if you do the Resistance check, per the manuel, its almost imposible to spot the bad stator, ( unless the section is completly OPEN )

 

I did the resistance check on my bad Stator , on my 89, after removeing it from engine.

The Resistance check, per manuel, said the thing was good !! but half the wires on the lower Coils , were melted, and Burnt up !!

 

Read the voltage, with everything connected,

[Flyinfool]

No, your not takeing the AC readings thru the R/R unit.

 

Find the white plug, directly out of the stator. With plug connected, and engine running, stick Red meter lead into each of the 3 wires at the big white plug, and

read the AC voltage to ground .

 

What you are looking for, is that the AC is about the same on each of the Three Phase's output from the Stator.

The voltage will vary with engine RPM changes.

 

If the lower section of stator is Fried, then one of the three will be much lower then the other two !!

 

However, if you do the Resistance check, per the manuel, its almost imposible to spot the bad stator, ( unless the section is completly OPEN )

 

I did the resistance check on my bad Stator , on my 89, after removeing it from engine.

The Resistance check, per manuel, said the thing was good !! but half the wires on the lower Coils , were melted, and Burnt up !!

 

Read the voltage, with everything connected,

 

I could be all wet here.

It is my understanding that there should be no connection from the stator windings to ground, this means that you must be reading through other components or you would show 0V on all three legs. I belive that what you are actually measuring is the voltage drop across the RR on each leg. This thery makes sense since the voltage readings that you say you have are the difference between the stator output and the regulated output. At idle the stator puts about around 20-30V the regulator outputs 14 volts and you are measuring about 5-15 volts. 6 V would be the voltage drop across the RR.

 

If there were a diode in the RR that failed short, that leg of the stator would read a lower voltage because it would be shorted to ground for a half cycle, if a diode had failed open then that leg would read high because the power would not be flowing out to the bike for a half cycle. Granted IF the RR is known good then your method will spot a bad stator as a lower voltage leg, but it does not rule out a bad RR if you do not know where the problem actually is. Testing the stator unplugged is testing just the stator with nothing else to possibly skew the test and then you will know for certain whether the stator is good or not. There is a test for each of the diodes in the RR to test that they are all working correctly. Unfortunately there is no easy direct test for the regulator portion of the RR, only a process of elimination, if the stator tests good and the diode pack tests good, the battery load tests good, but the charge voltage is still not right then it must be the regulator section that has failed.

 

I would love to test your burnt stator on my expensive ohm meter to see if it picks up the bad winding. If you still have it I will gladly pay the postage for you to send it to me for further testing.