Problem free PMA? well weren't you the lucky one. LOL
Note it's the new chinese parts currently giving him problems.
Note it's the new chinese parts currently giving him problems.
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10 cent charging diagnosis please...
- Thread starter MacMcMacmac
- Start date
Mac, I wonder if this isn't the time to consider the radio shack rare earth magnet overlay?
MacMcMacmac, on my 81' SH I left the old magnet in place and used Araldite to glue a new 0.5mm thick Neodymium magnet on top. The diameter of the magnet was the same as the original - 5 or 6mm I think? At 0.5mm thick the magnet passes easily as it rotates without fouling anything. The ignition worked well afterwards.
Good idea, except I am at a loss to find such a magnet locally and I have parts on hand to deal with this right now, so I decided to just put the oem rotor plate on the Rick's rotor.
The sure don't spare the lacquer at Rick's... OEM plate was fun getting off since I had, ahem, built it to last shall we say. I was going to do this with the crappy RM Stator rotor last year only to find the screw holes were indexed just a hair differently.
Once assembled, all seemed well. The magnet holds the razor blade quite strongly.
I think I will try to pry out the magnet from the other plate and rewind the bobbin in the old rotor to have a spare when I get the time. Right now, I'm waiting for the rain to stop so I can put this sucker in.
The sure don't spare the lacquer at Rick's... OEM plate was fun getting off since I had, ahem, built it to last shall we say. I was going to do this with the crappy RM Stator rotor last year only to find the screw holes were indexed just a hair differently.
Once assembled, all seemed well. The magnet holds the razor blade quite strongly.
I think I will try to pry out the magnet from the other plate and rewind the bobbin in the old rotor to have a spare when I get the time. Right now, I'm waiting for the rain to stop so I can put this sucker in.
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The hackles on the back of my neck are standing up again...
YES Yes I am the lucky one. Almost a decade of service, without even pulling the cover off. So ggggggary if you love 19th century technology so much maybe its time to strap a horse to the front of your bike. PS My SPARX system was made in England.
Well, success! I installed the assembled rotor and it started with one half kick. 12.95V at 2000 rpm, which seems a trifle low but the rotor did ohm out a bit high. I did see 13.75 with a few revs, so I'll take it. Yamaha original parts FTW!
One thing I also noticed with the Rick's rotor was that one of the leads had almost no solder on it and was loose on the terminal, so it was going to be trouble eventually anyway.
I didn't want to give up on the Ricks rotor plate, so i popped out the magnet. I drilled a hole behind it and pushed it out with a pick. That magnet was absolutely dead!
The hole was about .013" too small for the 1/4" magnets I found, so I carefully enlarged the hole by turning a 1/4" bit backwards at slow speed. I was successful, and I will now mount a 1/4" neodymium magnet in the hole with some epoxy. It fits perfectly. I got these at an arts and craft store called Michaels.
Then comes the hard part of pressing the original Yamaha rotor apart, retrieving the plastic spool inside it, removing the RM Stator original windings, and rewinding it with the 21 gauge wire I bought last year from a rewind shop.
Just to rub salt in the wounds I measured the rotor I pulled off and it came up a perfect 5.0 ohms. I hate intermittent failures.
One thing I also noticed with the Rick's rotor was that one of the leads had almost no solder on it and was loose on the terminal, so it was going to be trouble eventually anyway.
I didn't want to give up on the Ricks rotor plate, so i popped out the magnet. I drilled a hole behind it and pushed it out with a pick. That magnet was absolutely dead!
The hole was about .013" too small for the 1/4" magnets I found, so I carefully enlarged the hole by turning a 1/4" bit backwards at slow speed. I was successful, and I will now mount a 1/4" neodymium magnet in the hole with some epoxy. It fits perfectly. I got these at an arts and craft store called Michaels.
Then comes the hard part of pressing the original Yamaha rotor apart, retrieving the plastic spool inside it, removing the RM Stator original windings, and rewinding it with the 21 gauge wire I bought last year from a rewind shop.
Just to rub salt in the wounds I measured the rotor I pulled off and it came up a perfect 5.0 ohms. I hate intermittent failures.
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Intermittent resistance measurements: At close to 20 Celsius the coefficient for copper wire is approximately 0.4 percent per degree Celsius. The rotor specification is 5.25 +/- 10% at 20 Celsius. When measuring the resistance at 0 Celsius the result will appear 8% low and at 60 Celsius it will be 16% high. I once checked my resistance after a ride and got 6 Ohms and when tested cold during winter got a low value. When tested at 20 Celsius in the house after several hours I got 5.3 Ohms. This was all on a freshly rewound rotor.
Perhaps temperature is an issue here??
Perhaps temperature is an issue here??
Could be Paul. It is working well now though, so my trials with this particular rotor are over for now. I took it for a nice long spin around the city and it has never worked as well as it is right now. Starting smartly on the button and no dying at the lights or during heavy braking. I'm liking the new UNI pods and upjetted carbs. Thanks to all who put in the hours of fiddling so that guys like me can read the results like a cookbook and swap in the parts and ride.
Well well well......
After a beautiful late evening rider where I maxed her out to about 95mph, I decided to stop for a coke and ponder life. It was such an enjoyable evening, I didn't even mind that the second and last sub side panel of my 83 Heritage went awol somewhere out in the boondocks. Things get pretty shakey at 150km/h on an XS. At least my replacement muffler supports weren't cracked like the last ride. Unfortunately, I noticed that I had somehow managed to lose the headlight. Probably another vibration victim I guessed. Shame, I had just replaced it a week ago. I checked it the next day and, weirdly, both filaments were intact. Did I crack up the headlight fuse too? No, it looked fine and had continuity. Aha! The infamous headlight safety relay. I pulled it out and cleaned off the decades dead spiders from the contacts. As I did, I shorted out two leads, heard a click, and the headlight came on. I did this with both relays, turning them on and off at will. Dang, curiouser and curiouser. So I did a little research and found that there was a yellow wire coming from the alternator that triggered these relays once the motor was running. I began to get a sinking feeling.....Yup, no voltage on that wire. Checking the battery at fast idle got me 11.55V and dropping very slowly.........F......F.....S!
I checked the rotor and got no continuity. That was actually encouraging, since I figured it suggested a broken wire at the joints, and indeed, after I got home and pulled the rotor, there was the wire hanging loosely from one terminal. Ha! Easy peasy! Except trying to strip the insulation from the wire got me a shorter wire. The another shorter wire. Well, effit, the rotor ohmed out high anyway, so I uncoiled one wrap and soldered it on good and stiff. I was preparing to mix up a batch of epoxy to anchor the wire good and hard when I decided to remeasure the continuity.
Infinite effing ohms.
I resoldered, but no dice. There was continuity from the terminals to the rings, but no continuity from ring to ring, so the wire is split somewhere amongst the coils.
Did I mention
F...F...S!!!!!!
Then I noticed the plastic bobbin that the wires were in could easily be spun by hand inside the rotor cage. Whatever used to anchor the bobbin was obviously not up to the job. Maybe it was the hard riding, but you'd think it would be manufactured to withstand any conditions it was likely to see. The bobbin must have rotated inside the rotor halves and pulled the wires apart. Maybe I'll press this one apart and see if the break is near the end and get it running, but frankly, I have lost all confidence that I can ever find any rotor that's going to fix this for good. It's easy to say the XS has excellent aftermarket support, but frankly, just about every aftermarket part I have bought has been of poor to barely acceptable quality. Case in point, the new Mike's/XS650Direct chrome front fender I just installed. Seems sturdy enough, unfortunately it leaves no room for the brake line stays, so now they just hang, supported only at the ends.
I think I'm done with this bike. I'll probably just throw on a cheap Chinese wobbler and sell it on. The wrenching to riding ratio is solidly in the red. It's a lovely city bike, and the lines are beautiful to look at, but there is always something needing to be fixed. Fun for awhile, but I think I'm over it now.
After a beautiful late evening rider where I maxed her out to about 95mph, I decided to stop for a coke and ponder life. It was such an enjoyable evening, I didn't even mind that the second and last sub side panel of my 83 Heritage went awol somewhere out in the boondocks. Things get pretty shakey at 150km/h on an XS. At least my replacement muffler supports weren't cracked like the last ride. Unfortunately, I noticed that I had somehow managed to lose the headlight. Probably another vibration victim I guessed. Shame, I had just replaced it a week ago. I checked it the next day and, weirdly, both filaments were intact. Did I crack up the headlight fuse too? No, it looked fine and had continuity. Aha! The infamous headlight safety relay. I pulled it out and cleaned off the decades dead spiders from the contacts. As I did, I shorted out two leads, heard a click, and the headlight came on. I did this with both relays, turning them on and off at will. Dang, curiouser and curiouser. So I did a little research and found that there was a yellow wire coming from the alternator that triggered these relays once the motor was running. I began to get a sinking feeling.....Yup, no voltage on that wire. Checking the battery at fast idle got me 11.55V and dropping very slowly.........F......F.....S!
I checked the rotor and got no continuity. That was actually encouraging, since I figured it suggested a broken wire at the joints, and indeed, after I got home and pulled the rotor, there was the wire hanging loosely from one terminal. Ha! Easy peasy! Except trying to strip the insulation from the wire got me a shorter wire. The another shorter wire. Well, effit, the rotor ohmed out high anyway, so I uncoiled one wrap and soldered it on good and stiff. I was preparing to mix up a batch of epoxy to anchor the wire good and hard when I decided to remeasure the continuity.
Infinite effing ohms.
I resoldered, but no dice. There was continuity from the terminals to the rings, but no continuity from ring to ring, so the wire is split somewhere amongst the coils.
Did I mention
F...F...S!!!!!!
Then I noticed the plastic bobbin that the wires were in could easily be spun by hand inside the rotor cage. Whatever used to anchor the bobbin was obviously not up to the job. Maybe it was the hard riding, but you'd think it would be manufactured to withstand any conditions it was likely to see. The bobbin must have rotated inside the rotor halves and pulled the wires apart. Maybe I'll press this one apart and see if the break is near the end and get it running, but frankly, I have lost all confidence that I can ever find any rotor that's going to fix this for good. It's easy to say the XS has excellent aftermarket support, but frankly, just about every aftermarket part I have bought has been of poor to barely acceptable quality. Case in point, the new Mike's/XS650Direct chrome front fender I just installed. Seems sturdy enough, unfortunately it leaves no room for the brake line stays, so now they just hang, supported only at the ends.
I think I'm done with this bike. I'll probably just throw on a cheap Chinese wobbler and sell it on. The wrenching to riding ratio is solidly in the red. It's a lovely city bike, and the lines are beautiful to look at, but there is always something needing to be fixed. Fun for awhile, but I think I'm over it now.
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Charging system is its demon in all these bikes. Ask me how I know? lol there is no bike like these and that is what took me back to wanting one. Yeah they can be a pain but man they are a blast when going. My Roadstar is fun and can go 80mph all day long and I can keep up with it. But not as fun as my XS!
ksrebel............do some research.......A lot of 20th century Yamaha PMA's are still used and were an alternative used as a replacement for the stock XS650 charging unit for 2 reasons..................
Suzuki had an ongoing problem on some models running PMA's...............
21s't century produced cheap PMA systems have been problematic due to a lack of understanding buy the suppliers, (not manufacturers), and pushing false information to unsuspecting and uninformed buyers, and the products haven't stood the test of time............solutions to some of these cheap products are to spend more on some expensive part to compensate for the unbalanced ill thought-out system.
Suzuki had an ongoing problem on some models running PMA's...............
21s't century produced cheap PMA systems have been problematic due to a lack of understanding buy the suppliers, (not manufacturers), and pushing false information to unsuspecting and uninformed buyers, and the products haven't stood the test of time............solutions to some of these cheap products are to spend more on some expensive part to compensate for the unbalanced ill thought-out system.
The Hail Mary rotor sits at work with the epoxy drying overnight. I managed to press apart the Rick's rotor and reclaim the windings intact. The second wire had split just under the spool edge, so I had plenty of wire to work with. It now ohms out at 5.7. I noticed before I pressed it apart, that after the rotor had cooled down, the plastic spool was now held tightly again, so it seems like it was loosening up as it heated up.
So, OEM Yamaha face plate, RM Stator plastic bobbin with the Rick's Electrosport windings inside, all pressed inside the modified Yamaha OEM rotor cage, epoxied to within an inch of its life to keep the wire spool from spinning inside the metal pole plates. I may have to shim the ignition sensor and brush holders, since it is about 1.5mm thicker now.
One thing I noticed about the Rick's rotor is that the rotor shaft that presses into the opposite half was not knurled like the RM Stator and OEM rotors. They assembled the two halves then staked the end of the inner shaft around with a center punch. That doesn't seem terribly stout. I would have at least smeared some red Loctite on the shaft beforehand if it were me. There was not much to hold the windings in place except whatever insulating lacquer made its way between the windings spool and the inner side of the steel rotor claws.
Hopefully that is the end of this little saga. If this one fails, I sure won't be harvesting any useful bits with the amount of epoxy I used..
Someone light a candle!
So, OEM Yamaha face plate, RM Stator plastic bobbin with the Rick's Electrosport windings inside, all pressed inside the modified Yamaha OEM rotor cage, epoxied to within an inch of its life to keep the wire spool from spinning inside the metal pole plates. I may have to shim the ignition sensor and brush holders, since it is about 1.5mm thicker now.
One thing I noticed about the Rick's rotor is that the rotor shaft that presses into the opposite half was not knurled like the RM Stator and OEM rotors. They assembled the two halves then staked the end of the inner shaft around with a center punch. That doesn't seem terribly stout. I would have at least smeared some red Loctite on the shaft beforehand if it were me. There was not much to hold the windings in place except whatever insulating lacquer made its way between the windings spool and the inner side of the steel rotor claws.
Hopefully that is the end of this little saga. If this one fails, I sure won't be harvesting any useful bits with the amount of epoxy I used..
Someone light a candle!
Oh Great Prince Of Darkness pass thee by my humble abode this gentle summer.
Well that didn't work. Careful shimming of the brush holder and ignition pickup did not prevent the expansion of the parts from allowing the slip rings to touch the aluminum casing. It's fun trying to get home with a total loss electrical system, no spare fuses, no toolkit and a battery reading 11.5V. Somehow I feel there is a lesson to be learned here.....
Note to self: Rotor thickness is crucial on these bikes. Also, be sure to blow fuses and break down within walking distance of a dollar store so you can buy a few $2 screwdrivers and tape to bodge together a get-home arrangement.
The positive brush spring was a lovely shade of blue, and was not nearly as springy as it had been. Funny that.
I refuse to spend another $150-$250 for another rotor that may not be any better than what I have received to date.
Well, that's my excuse for being bullheaded anyway.
Back to the house of pain.
Note to self: Rotor thickness is crucial on these bikes. Also, be sure to blow fuses and break down within walking distance of a dollar store so you can buy a few $2 screwdrivers and tape to bodge together a get-home arrangement.
The positive brush spring was a lovely shade of blue, and was not nearly as springy as it had been. Funny that.
I refuse to spend another $150-$250 for another rotor that may not be any better than what I have received to date.
Well, that's my excuse for being bullheaded anyway.
Back to the house of pain.
Damn in spite of the problems you made me 
about the convenient $2 store! At least once I roadside repaired my bike by shopping a convenient garage sale. Spent 50 cents on tools and supplies. 
about the convenient $2 store! At least once I roadside repaired my bike by shopping a convenient garage sale. Spent 50 cents on tools and supplies.
Well, as I walked back from the dollar store I crossed a street with the same name as my dear old departed dad, so I figured he was looking out for me.
I'm beginning to feel like I'm serving as a bad example for the rest of the membership here though.
I'm beginning to feel like I'm serving as a bad example for the rest of the membership here though.
jussumguy
XS650 Addict
No don't feel bad, I've learned a lot here. I'm even considering winding up my own rotor and gluing a magnet to it. I have the same feelings about keeping my fleet of antiques rolling. Just keep one modern bike around that isn't so needy. It's easier to stay sane.
I appreciate your posts
I appreciate your posts
Well, I guess being stubborn has paid off. I pressed it all apart again, and delicately removed one end of the wire spool to thin out the entire assembly. I gained about 2mm. I then went to the bead blaster, rendered the pole plates surgically clean and reassembled the rotor with an accuracy heretofore unknown in the realm of the XS650. I gave all the windings a good coat of epoxy, gave a good three turns of wire on each terminal, soldered them up and epoxied the wire lead into place. I had earlier hand lapped the rotor plate on a cast iron bandsaw table with a piece of emery cloth and got everything shiny and flat.I put some press fit retaining compound on the knurl since I feel this many assembly and reassembly go-arounds was doing nothing for the press fit. I used the same stuff on the plate retainer screws last time and they held beautifully. Ohmed out at 5.7. Put it on, no interference, no shorting, and 13.9V max on my little led voltmeter. Now I just need to give it a good run to see if it brings my battery back up. If so.........no...I'm not even going to say it.
Just so you know, this rotor can easily be pressed apart with a simple vise and some spacer blocks. You can use a big socket for clearance on the end of the stub shaft when you want to press it together again. Just be sure to accurately mark the relationship between the two halves and the wire terminal locations before you proceed or your timing may be affected.
I do have my 1200 Bandit around for my "trouble free" bike. Well, it was trouble free until I put the GSXR cams in it and missed the timing on the exhaust cam. Still waiting on replacements from Partzilla. Bandit 1200 + 1988-89 GSXR750 cams + 1988-1997 Katana 750 cylinder head + Black Widow headers + Yoshimura RS3 + RS38 carbs should have me in the 135hp range, which was what a good ZX11/Blackbird was putting out.
Just so you know, this rotor can easily be pressed apart with a simple vise and some spacer blocks. You can use a big socket for clearance on the end of the stub shaft when you want to press it together again. Just be sure to accurately mark the relationship between the two halves and the wire terminal locations before you proceed or your timing may be affected.
I do have my 1200 Bandit around for my "trouble free" bike. Well, it was trouble free until I put the GSXR cams in it and missed the timing on the exhaust cam. Still waiting on replacements from Partzilla. Bandit 1200 + 1988-89 GSXR750 cams + 1988-1997 Katana 750 cylinder head + Black Widow headers + Yoshimura RS3 + RS38 carbs should have me in the 135hp range, which was what a good ZX11/Blackbird was putting out.
