Partially cracked rotor magnet 1150

[Carter Turk]

Went on a short ride the other day with no starter clutch, bump started it. The rotor was on. I was maybe 45 miles into the ride, telling myself the bike felt happy and smooth without a rattling starter clutch, then I came to a stop, bike died. Headlight barely illuminated. Checked fuses, felt regulator, examined visible wires, nothing melted or hot. I pulled the fuse for the headlight, and pushed the bike to a slight hill to see it would start, bump start that is.

It started, so I tried to ride home, figuring it was gonna die again in about 10 minutes, so I tried to keep the revs above 3000 rpms, thinking it might charge more that way. Not sure if that accomplished anything, but I did make it home. I usually coast into the driveway in neutral, close the Pingle petcock and hit the kill switch, but this time I popped it into neutral and left it running and it didn't die. I thought for sure it would when I rolled off the throttle. I checked the battery voltage when I got off the bike, 11.66V. It's a Yuasa, lead acid, purchased in June. All the cells had fluid between the high and low marks. It has a Duanage RR and a stator I bought from the cafe kid 5 years ago.

Wondering if a partially cracked magnet would change charging characteristics? Or the loose pieces from my starter clutch greande, ground out my stator windings? Thanks for any thoughts or insight.

 

[Guest]

You are going to have to look and assess any stator damage. I would test the magnets with a steel blade or screwdriver. If the partially cracked one seems as strong as the others I would float some epoxy in the crack and let it go. It probably won't make much difference. If it feels weaker than the others I would replace it if it were mine. As for the R/R, it's as good as the shunt R/R's go, but it is old technology and a series R/R has many benefits including allowing the use of LED's without risking fooling the shunt R/R into overcharging with a reduced load.

 

[posplayr]

Do a quick test to assess whether or not you are charging..................

 

[Carter Turk]

Do a quick test to assess whether or not you are charging..................

Easier to do with a starter clutch and good knees but will bump start and report back.

 

[Carter Turk]

Been pouring rain here last few days, power was out for 2 days, haven't done a quick test yet.

Excuses, I know.

Any thoughts on a cracked rotor magnet messing with incomplete charging?

 

[posplayr]

If a pole were to split as shown in this link it would certainly seem like it would limit the AC output.

https://www.nde-ed.org/EducationRes.../MagParticle/Introduction/basicprinciples.htm

 

[Carter Turk]

If a pole were to split as shown in this link it would certainly seem like it would limit the AC output.

https://www.nde-ed.org/EducationRes.../MagParticle/Introduction/basicprinciples.htm

Hey, thanks for that link. Perfectly explains what a crack might do to the magnetic field. Sounds like I might have a flux field leakage.

 

[Guest]

It's not all smoke and mirrors?
~

 

[Carter Turk]

It's not all smoke and mirrors?
~

Yeah, it is with electrical stuff. What does infinite resistance mean, what is 46 ohms vs. 3 ohms?

Even if I know what it is, which I don't, what's it telling me do after I see the number on the multi-meter?.

I have no idea. Laughable I know and sad too. Do I even have it on the right setting for the test?

As far as the crack on the rotor magnet, I might have more north and south poles than I need for complete charging.

Or it's something else all together.

 

[Carter Turk]

I never did the quick test, with the bump start situation complicating matters. I opted to swap out rotor, starter clutch (SC) and R/R from my other 1150. Only thing I added was new rollers in the SC. All these swapped parts functioned fine, even if the bike sat for a month or more, so I thought it might transfer reliability to my other bike.

I had to do some rewiring of connectors to swap the R/R, and failed miserably at that. Used marine grade connectors and heat shrinked all the connectors, but the crimping tool or lack of a proper one, had all the connectors hanging on by the heat shrink. My 3 month old battery was reading 13.2ishV at rest after trickle charge, but then when the key was turned on with head light, it dropped rapidly to 11.82V.

Once the swap was complete, I jumped it off a non running van to aid in eliminating starter clutch snatching, spinning the motor first before firing the coils. Fired instantly, but no charging at any rpm. Then I discovered the connectors weren't tight, so I soddered the connections ( which likely should have done in the first place) bought a new battery and fired it up. Volts were on the rise, but the multi meter was jumping all around, so I couldn't discern what was happening at 2500rpms or higher. I saw 13.5 something, a number I hadn't seen recently, so I rode to about 40 miles to guy who owns a shop, who I've done a few trackdays with. He was willing to trouble shoot with me.

He said he had gixxer 600 R/R with 5 wires, so we tried that, checked the one the bike and a third one. We saw almost 17V on all of them. Near 15V at idle, high beam didn't seem to do anything to the readings.

The closest Polaris 775 is 4 days away from a dealer, but I was trying to ride to California from Washington today. Not happening, gonna have to drive the van, ugh.

I pulled and cleaned-dielectric greased all the connectors, thinking the functioning parts I swapped were good to go.It doesn't pay to wait till the last minute. I guess all three R/R's were already shot or I didn't ride far or long enough to notice overcharging?

 

[trippivot]

hi what are the chances of 3 failed regulator regulators? - well, nevermind , used parts are used parts they work or they don't -you can bench test the 6 rectifier diodes not the regulator . that half it works or it does not work. a bad battery can give false test results. so can a bad ground. I'm sure you are getting tired of electricity.


I love the reliability of the middle 80s' Kawasaki reg/rct. KZ 1000 J models especially police units, but that is my preference. many many reg/rct will work but you need one that can handle the peak 3 phase AC voltage. A good GS one will peak over 140 ACV on all legs , talk about why R/R get HOT!! I run away from anything POLARIS - ugh .. I'd get a used one from a KZ before a new Polaris anything. Polaris probably gets shinnengen seconds lower quality. I cringe when a sportsman 500 or Polaris anything hits my lift.. heck a reg/rct from a EX500 A-thru D,, ZX600A-C,, I can go on... cbr600F2 is a very compact one that will last more than 5 years.

the battery load test is the one most guys refuse to believe--- I just bought that battery!! is a common statement - right? - which I see you replaced yours... good - take care of it , they are getting weaker and more delicate as the E.P.A. messes with caustic acids and LEAD.


The main and very important test is the unloaded AC output test performed between the 3 AC stator wires at idle and revved up to 3K or 4K rpm - (1-2)(1-3)(2-3) AC Voltage HAS TO BE OVER 26~30 ACV @ 1000 rpm idle. if it is low as 24acv you need a stator - or more magnetism - very UNcommon to need more magnetism. I have had broken magnets in a rotor no whoop they work and centrifugal force keeps them still. - but I changed it out before it disintegrated and made a mess. yes starter clutch parts will hurt your stator.

AC voltage is created by the flux lines from the magnets traveling through the copper wire windings - As I understand it , if your magnet breaks it creates new poles , both N and S - more poles mean more flux lines , which - to me, means you get more AC induction . I disagree with the link photo that shows the flux lines going thru the fracture and around the whole magnet -

try it- get some magnets - fine metal shavings and a sheet of paper - only way to see flux lines and the polarity field of a magnet. science is fun.

 

[Carter Turk]

hi what are the chances of 3 failed regulator regulators? - well, nevermind , used parts are used parts they work or they don't -you can bench test the 6 rectifier diodes not the regulator . that half it works or it does not work. a bad battery can give false test results. so can a bad ground. I'm sure you are getting tired of electricity.


I love the reliability of the middle 80s' Kawasaki reg/rct. KZ 1000 J models especially police units, but that is my preference. many many reg/rct will work but you need one that can handle the peak 3 phase AC voltage. A good GS one will peak over 140 ACV on all legs , talk about why R/R get HOT!! I run away from anything POLARIS - ugh .. I'd get a used one from a KZ before a new Polaris anything. Polaris probably gets shinnengen seconds lower quality. I cringe when a sportsman 500 or Polaris anything hits my lift.. heck a reg/rct from a EX500 A-thru D,, ZX600A-C,, I can go on... cbr600F2 is a very compact one that will last more than 5 years.

the battery load test is the one most guys refuse to believe--- I just bought that battery!! is a common statement - right? - which I see you replaced yours... good - take care of it , they are getting weaker and more delicate as the E.P.A. messes with caustic acids and LEAD.


The main and very important test is the unloaded AC output test performed between the 3 AC stator wires at idle and revved up to 3K or 4K rpm - (1-2)(1-3)(2-3) AC Voltage HAS TO BE OVER 26~30 ACV @ 1000 rpm idle. if it is low as 24acv you need a stator - or more magnetism - very UNcommon to need more magnetism. I have had broken magnets in a rotor no whoop they work and centrifugal force keeps them still. - but I changed it out before it disintegrated and made a mess. yes starter clutch parts will hurt your stator.

AC voltage is created by the flux lines from the magnets traveling through the copper wire windings - As I understand it , if your magnet breaks it creates new poles , both N and S - more poles mean more flux lines , which - to me, means you get more AC induction . I disagree with the link photo that shows the flux lines going thru the fracture and around the whole magnet -

try it- get some magnets - fine metal shavings and a sheet of paper - only way to see flux lines and the polarity field of a magnet. science is fun.

Hey, thanks for your insight and the other bike RR possibilities. Would pulling a leg of the stator while running, lower the voltage? We tried that. Now, the next day at rest, battery is at 12.56V.

 

[gs11ezrydr]

I'M not sure about charging rotor magnets But I have had some ignition magnets have a hair line crack and caused running issues by double counting the cracked magnet. It was with some early car ignition modules The Customer went to several GM dealers and we put it on a scope and watched it double count. Witch threw all other 8 cyls. off. It thought it was counting 9 Replaced the magnetic module and repaired the problem. I'm sure it would have some effect on charging output also.

 

[posplayr]

AC voltage is created by the flux lines from the magnets traveling through the copper wire windings - As I understand it , if your magnet breaks it creates new poles , both N and S - more poles mean more flux lines , which - to me, means you get more AC induction . I disagree with the link photo that shows the flux lines going thru the fracture and around the whole magnet -

EMF and current is produced in a loop of wire when that wire moves through a magnetic field. This is first principles of Maxwell's laws. The higher the magnetic field or the faster the speed, the higher the current produced will be. In GS charging systems the magnetic field is produced by the rotating rotor (that is why it is called Permanent Magnet or PM generation), and the windings are the stator.

You get a pulse of AC every time a stator pole passes the center of a rotor magnet. The poles are arranged to generate 3 phase power (I think Nikola Tesla first developed this concept). The three AC waveforms are based on the physical arrangement of the poles and magnets and how many winding there are (3 in this case).

It turns out that with 3 phase (higher is possible ) and with ideal 3 phase rectification there is very little AC ripple on the DC line (R/R output). That Is the principle reason for the popularity of 3 phase AC at least in charging system. Higher phases further reduce the AC ripple but there is a diminishing return after 3 phase. Whatever is left over also gets dumped into teh battery and it is hard to push the battery around so and AC ripple is minimized further by the battery.
The point of this short diatribe is to explain why the rotor and the stator need a matched number of poles in the correct position.

I'm not so sure I would be so willing to dispute anything posted at that NDT website without some backup(they do get NSF funding you know). There is no mention of whether the flux is increased or decreased, but the point is that the air gap creates a new pole pair. The rotor poles have to be aligned with the stator poles in order to generate EMF(see diatribe). Maximum EMF is NOT when a split magnetic pole is aligned with a full stator pole. It would be minimal (as the EMF at the split is zero) where it should have been at a maximum EMF. Again teh phasing is important as it relates to the 3 phase timing, so you can't just put a pulse anywhere..

Bottom line is that in any AC machine (and DC for that matter) the magnetic field has to be orientated with respect to the armature windings else the motor will not work properly or efficiently or not at all. AC machines are specifically called "synchronous" machines specially because of the synchronism of the magnetic fields. It is not just a "bag of magnetic fields; it matters where the peaks occur.

g11ezrydr gives another example of where the magnet split caused a new pulse not where it should be and probably not of a lot of power but enough to fire the ignition as the ignition amplifies the magnetic pickups it does not actually run off the EMF power generated. The new pulse came because a new pole pair was generated. So the new pulse probably occurred in the middle a new magnetic segment created by one of the original air gaps and the crack. Had the crack not been there the pulse would have been centered between air gaps.

If your claim were true, then an 18 pole stator would produce more power out of an 16 pole rotor than a rotor matched to the 16 pole stator.We know it actually produces zilch despite having all of the same magnetic strength and more poles. Even the PM alternator is a synchronous AC machine, not a bucket of magnets.