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General Category => General Discussion => Topic started by: blackcat on September 11, 2019, 06:04:41 PM
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The charging light on my CX(Lemans II) Bosch system stays lit until about 2,000 RPM + or - but it is charging. I have removed the alternator cover to watch the brushes and they sort of bounce around quite a bit and I’m wondering if I should just replace the brush holders as they are about 12-15 years old. Springs are tight and plenty of meat on the brushes. I also installed an adjustable voltage regulator but that doesn’t seem to be changing much of anything. My other problem, and I think that I solved the issue is that on longer trips the battery is getting worn down, but since I rotated the brushes from 9 o’clock to 12 o’clock, gravity is helping the issue but I haven’t taken the bike for a long ride. Everything is grounded, all connections are clean and Deoxited. I haven’t polished up the rings but they look pretty clean.
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I wonder if the rotor is not sitting on the crankshaft taper properly, if its out of round the brushes might be bouncing and losing contact.
The key might be too large and holding the rotor out of centre., Perhaps set a dial gauge and rum on the shaft then run it again on the slip-rings.
I found on my California II that if I cleaned up the slip-rings with a dry cloth the alternator would produce more current for a while, I think the brushes would make better contact for a while.
I would also check every diode in the rectifier in case there's a couple of bad ones.
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It's been a while since I worked on a Bosch alternator of that type, but if the brushes are "bouncing" I'd check to see if the slip rings are out of round or the rotor is not straight on the crankshaft.
Either can be verified with a dial indicator on the slip rings.
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My thoughts much the same, something is out of round/not true if the brushes are bouncing.
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I will pull the rotor and see if I can reposition it on the shaft. The seal was replaced about a year ago and maybe I did something wrong when I re-installed as there wasn’t a problem when the rotor was replaced a few years ago. Thanks
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It's hard to get wrong unless there was an unnoticed burr or piece of dirt on the taper.
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The key might be too large and holding the rotor out of centre.
No key on the tapered nose cranks/Bosch charging systems.
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What is your battery status? Age? Overnight standing voltage?
The system has to use battery input to 'boot-strap' and begin to generate more than it consumes. Beginning with a weak battery may mean higher rpm to generate a charge.
What battery technology? AGM batteries have a slightly higher standing voltage and this helps to begin the charging function earlier. Find a good AGM and just jumper cable to your bike. See if it generates earlier or at lower rpms.
Patrick Hayes
Fremont CA
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The service limit for brushes is something like 16mm new, half that - replace.
If you have to, you can run them longer, but tension on them goes down the shorter they are.
Try shimming them to get a bit more spring tension, that might be all you need. Until replacements arrive.
And do measure them - that's the best way to tell, but if the spring is getting close to bottoming on the plastic holder you know they're getting short. I've seen the rear brush wear significantly more than the front one, so don't presume they're both in the same condition.
Someone came up with a way to attach the brushes without having to remove the stator. By attaching a ring terminal on the end of the lead no soldering is necessary.
This problem does sound like the classic 'brushes almost all worn out' symptoms.
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Disconnect the clock. Its running all the time and if you don't ride often your starting off with a low battery.
Also the volt meter isn't one on the best takes to long to register what the charging system is doing, if you insist that you need a voltmeter search the web and find one with a more sensitive movement..
TOMB
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There was a service bulliten to position the brushes at 3 or 9 oclock, dont remember which, to prevent road bumps from causing brush bounce.
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Battery status is fine as I swapped out another battery with the same results.
Brushes were at 9 and I moved them to 12 with better charging results. Short runs at 9 were showing 12.7, moved to 12 and I’m now getting almost 13.
I have to measure the brushes, but a quick look says they are OK but it might be a problem.
Can’t work on it today, but will pull everything tomorrow night and report back with what I have
I do have another rectifier, so maybe I should just put that in, but i’ll try the basics before doing that work.
No clock, just the basics and the Dyna ignition.
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FWIW, I was getting low charging on the AeroLario the other day, and it was a weak crimped connector on the yella wires.
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FWIW, I was getting low charging on the AeroLario the other day, and it was a weak crimped connector on the yella wires.
I will check it out, but the wiring is a fairly new Greg Bender harness.
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If you don't have one already, the addition of Greg's "bootstrap harness" may help. Really seemed to help on my Convert, along with the solid state adjustable voltage regulator.
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If you don't have one already, the addition of Greg's "bootstrap harness" may help. Really seemed to help on my Convert, along with the solid state adjustable voltage regulator.
What exactly does the bootstrap do? I already have an adjustable VR.
I have no idea how long the brushes are suppose to be but these look short, maybe not.
(https://i.ibb.co/KGRNc86/E83-C6-E6-D-A749-4477-8592-5-C4-CA27792-C7.jpg)
Cleaned up the rings after this photo, have continuity but unless I’m doing something wrong which is quite possible, I keep getting a reading of 2.5 ohms and it is suppose to be 3.4 ohms.
(https://i.ibb.co/9v4TwLM/E5-B5-C992-70-B2-474-D-AA7-E-52588-E832072.jpg)
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A lot of brushes have a score mark on the face to indicate maximum wear. Don't know whether Guzzi do this though.
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What exactly does the bootstrap do? I already have an adjustable VR.
Eliminates the need to have the warning light working, seems to improve charging - more volts at lower rpm.
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The front brush looks good - probably 16 or 17mm. New is around 18mm. Be sure to check the other one in the rear - it tends to wear a lot more than the front one.
Another possibility is spring tension. I seem to recall a whole turn is needed, but I'll check. Yes - that's the data I have - when brushes are new, the spring will be almost one whole turn. The one I see appears to be a half turn. That could be it right there.
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Those brushes are not the problem
Just maybe (seen it once, twice or a thousand times but no promises)
Clean the inside of stator
You say you changed the seal, if oil gets on inside of winding it stops it working (as does brake fluid)
Wet alternators are somehow different
Spray with contact cleaner until eat yer dinner off clean, try again
Best
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I've seen the springs bottom out from what looked like not worn brushes...new brushes solved 3 years and 20k miles of charging issues on a friends LeMan V...at a short glance it looked fine, but the bottomed spring is hidden from view....whole new bike and a whole new confidence level
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If you're going to take the time to pull the rotor, put in a Euro Moto electrics charging system and never look back.
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Eliminates the need to have the warning light working, seems to improve charging - more volts at lower rpm.
Thanks Charlie, wish I had known that when the harness was replaced.
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Those brushes are not the problem
Just maybe (seen it once, twice or a thousand times but no promises)
Clean the inside of stator
You say you changed the seal, if oil gets on inside of winding it stops it working (as does brake fluid)
Wet alternators are somehow different
Spray with contact cleaner until eat yer dinner off clean, try again
Best
Yes, the inside was a mess and I’ve cleaned it but it is still a bit grungy. Brake cleaner OK?
I cranked up the springs, maybe that will help.
I’m not against spending the $500 bucks on the Moto electrics unit if this was my only bike and I was running full suit electrics but that isn’t the case. The last time I had charging problems on the bike was a dozen or so years ago so I’m willing to wade through whatever is the problem. I’m now starting to think the oil coated stator is the problem.
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The oil could be contaminating the brushes and their contact with the slip rings. I had an older airhead that sat unused for a long time. The brushes looked good, but had left a black coating on the slip rings. It stopped charging and left me stranded. Cleaned the slip rings and all was good. I'd maybe even use Gunk or kerosene or Greased Lightning or Simple Green to clean it up. For a final clean up, use the brake clean.
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The oil could be contaminating the brushes and their contact with the slip rings. I had an older airhead that sat unused for a long time. The brushes looked good, but had left a black coating on the slip rings. It stopped charging and left me stranded. Cleaned the slip rings and all was good. I'd maybe even use Gunk or kerosene or Greased Lightning or Simple Green to clean it up. For a final clean up, use the brake clean.
I’ve cleaned it up with Simple Green, just going to spray it down with brake cleaner and see what happens.
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Be very careful with brake ( not break) cleaner, some is not so clever, contact clean or alcohol safer.
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Be very careful with brake ( not break) cleaner, some is not so clever, contact clean or alcohol safer.
Yes, brake.
Well, everything is back together, the light goes off much quicker than before and it easily reaches 13.2 at the usual rpm’s but I will see what happens tomorrow after a longe run at a sustained higher speed(s). The light still glows at idle, but I forgot to adjust the VR, so maybe that will solve that issue.
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Thanks Charlie, wish I had known that when the harness was replaced.
It's a simple little harness - just a wire with resistor - that can be added at any time.
Rectifier to fuse panel
Connects the rectifier to fuse number 5 to bootstrap the charging system. Comes complete with 2 watt, 82 ohm resistor soldered in place (as original). $6.75
(https://i.ibb.co/mh6s64K/wiring-subharness-tonti-rect-bootstrap-1.jpg) (https://ibb.co/mh6s64K)
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All the resistor is doing is bypassing the charging light. The light will still come on normally and let you know if something aint right, but if the light blows out, the alternator will still charge. When the alternator is charging and the light goes out, no current will be going through the resistor, so it won't get hot. The alternator may even start charging at a lower RPM with the resistor.
I don't know that any of my bikes with the Bosch charging system have charged at idle. The light is always on at idle, but it doesn't hurt anything.
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Yes, brake.
Well, everything is back together, the light goes off much quicker than before and it easily reaches 13.2 at the usual rpm’s but I will see what happens tomorrow after a longe run at a sustained higher speed(s). The light still glows at idle, but I forgot to adjust the VR, so maybe that will solve that issue.
All good, idle light normal
Love it when it’s easy, normally is with Guzzi, simples
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2,000 RPM is when the charging light extinguishes on a first start on my T3. Once the system has power running through it to maintain rotor magnetism the charging light goes out sooner. The charge indicator bulb is used as a resistor and passes a current through the rotor to produce a weak magnetic field. This is enough to start current production. The system is then self supporting. Just always check that your charge lamp lights at KEY ON. Then you don't need a bootstrap. It only functions at the start up.
In your first photo the brush springs are installed 180 degrees out of rotation (and spring tab is on the wrong side of the mounting ear.
(https://i.ibb.co/cxnXtdT/1568533555963.jpg) (https://ibb.co/cxnXtdT)
That will allow your brushes to bounce on the slip rings. Spring should carry at least a full turn wind up. Seems to me I read an 8 pound spec for brush spring pressure somewhere or other. You said you corrected that and charging is currently normal. Looks like your problem is solved.
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Mine after a rebuild with a combined reg/rec needs to get up to 2,000rpm before the light goes out..previously went out around 1,500.better charge though !!
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It doesn't make sense the light staying on till 2K. I can't see a good reason why that should be normal when everything is right.
I'm really curious what's keeping the light from extinguishing at 1200 or 1500 RPM? That's not right at all and I'd be looking for the reason why. I always thought the charge light connected to the alternator, but from diagrams it's connected to terminal D+ (61 is the same thing) at the diode board. That terminal is directly connected to the voltage regulator, and from there is connected to DF at the alternator. My thought is there's a poor connection somewhere along the way, or it has something to do with the VR.
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Is the charge light always on below 2K or just on the initial run up? I only see mine on at 2K on the initial run up, until the system becomes self sustaining. Subsequent light appearances are only at a very low RPM.
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Mine behaves exactly the same as yours n3303j.The regulater/rectifier is a sachse unit.The warning light is a led with built in resistance so this could be the reason too ??
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I'll have to pay more attention to mine at first start up. See if it's any different.
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I'll have to pay more attention to mine at first start up. See if it's any different.
The AeroLario is that way, too. First start, the light doesn't go off until 2k rpm, then after that it stays off.
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Is the charge light always on below 2K or just on the initial run up? I only see mine on at 2K on the initial run up, until the system becomes self sustaining. Subsequent light appearances are only at a very low RPM.
At lower rpm’s, like idle, it’s always on.
Went for a long ride today and at the first stop(60 miles) the battery was at 13.1 with the headlight on, then the next stop was about 90 miles later and the battery was down to 12.3. NG. Turned off the light and did another 90 miles with the battery reading 13.1-2. At first I thought it was a failing battery but that doesn’t seem right either, so it might be something in the wiring of an Eastern Beaver light relay kit. Sometime this week I will remove the relay and see if that solves the problem. https://easternbeaver.com/Main/Wiring_Kits/H4_Kits/h4_kits.html
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Sounds like you either have a lot of drain on the system or low output. I'm running a stock system except for a higher output EME solid state regulator. Never had any problems keeping up with stock T3 lighting, Garmin Zumo and heated grips (2 or 4 amp depending on heat settings).
First start takes 2K RPM to put out the light. My idle is about 1,150. I don't get the light at those idle speeds. Running an Odyssey 925 and never ran it out. The Odyssey is 10 years old and hasn't been treated with gentle care. It has 70K miles on it. That old Bosch System is great.
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blackcat - where were you taking the voltage readings? At the battery or a volt meter wired into the system? Where in the system?
As the battery gets all charged up following the starter draining it, and lights at idle, the alternator will put out less electricity since the battery needs less. I wonder if that's what you're seeing?
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blackcat - where were you taking the voltage readings? At the battery or a volt meter wired into the system? Where in the system?
As the battery gets all charged up following the starter draining it, and lights at idle, the alternator will put out less electricity since the battery needs less. I wonder if that's what you're seeing?
Taking the readings with a hand held meter at the starter or battery with the same readings.
Battery is an Odyssey 925 and another new battery was also used with the same results. Nothing else is running electric except the lights and the Dyna.
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The readings came directly from the battery while the engine was running. Got it. Down to 12.3 doesn't sound good, though at idle you're running off the battery and by the time the reading was taken it's possible it ran down a little. It's evidently charging since it didn't leave you stranded on the ride. What's the voltage at 3K RPM? Does it make it up past 14 volts?
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There has been quite a bit of Odyssey research on the V11 lemans forum. First, an Odyssey needs to be conditioned by a dedicated charger. If it is really low, it takes a minimum of 6 amps to charge it. Best voltage is mid 14s on the bike, but never over 15. That will cause them to outgas.. not a good thing. Once properly conditioned, they will last for years.
That said..
To me, it sounds like you have low charging voltage on the bike for whatever reason. Definitely 13.3 won't get it. 14.3 would be more like it.
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Nope, not getting to 14 volts.
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Sum Ting Wong, that Chinese mechanic, says <scratching head> Dunno. :smiley:
I was getting low voltage and as I mentioned, had a loose crimp on a connector at the alternator. I've also had corroded fuses cause it. Could be corrosion on a Molex connector. I've seen that, too.
DeOxit is your friend, though. If it were me, I'd have every connector apart, give it a squirt, wiggle it around, oh you know..
You can do the whole bike in a couple of hours. Your electrical system will thank you.
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As the battery gets all charged up following the starter draining it, and lights at idle, the alternator will put out less electricity since the battery needs less. I wonder if that's what you're seeing?
The voltage however should be up, around 13.8 to 14.2 volts running on a fully charged battery.
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Sum Ting Wong, that Chinese mechanic, says <scratching head> Dunno. :smiley:
I was getting low voltage and as I mentioned, had a loose crimp on a connector at the alternator. I've also had corroded fuses cause it. Could be corrosion on a Molex connector. I've seen that, too.
DeOxit is your friend, though. If it were me, I'd have every connector apart, give it a squirt, wiggle it around, oh you know..
You can do the whole bike in a couple of hours. Your electrical system will thank you.
Went through all the connectors and DeOxit was used at every connection. I’ll double check it again
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The voltage however should be up, around 13.8 to 14.2 volts running on a fully charged battery.
When I wrote that, it was from the viewpoint of a meter on the dash. But come to think of it (been a long time since I've watched one of those), the volt meter read low until the battery was all charged up.
And yes, the battery should be at 12.7 or so at a minimum. If it's being charged they usually read 13+.
Even though the system is working now, it's not optimum. Sounds like you found and corrected some faults, but there's more to go.
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Did you check all the diodes in the rectifier?
In particular the 3 small ones that feed 61 and D+
http://www.thisoldtractor.com/guzzi007/schematics/1978_V1000_SP.gif
If you have a diode test on your meter it should read 0.6 Volts from each yellow wire to 61
Another test you can do while you are measuring the battery with engine running, terminal 61 or D+ should be almost identical to the battery Voltage, it may be lower at idle but should reach battery Voltage at revs
The regulator actually uses this as the battery Voltage for regulation purposes.
In the interest of troubleshooting could you rev the bike and read D+ and also DF at 2000 RPM it goes without saying D- at the alternator and the regulator should be reading zero (well grounded)
From those readings we might be able to figure out where the problem lies.
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I'm confused, KR.. what is 61?
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Did you check all the diodes in the rectifier?
In particular the 3 small ones that feed 61 and D+
http://www.thisoldtractor.com/guzzi007/schematics/1978_V1000_SP.gif
If you have a diode test on your meter it should read 0.6 Volts from each yellow wire to 61
Another test you can do while you are measuring the battery with engine running, terminal 61 or D+ should be almost identical to the battery Voltage, it may be lower at idle but should reach battery Voltage at revs
The regulator actually uses this as the battery Voltage for regulation purposes.
In the interest of troubleshooting could you rev the bike and read D+ and also DF at 2000 RPM it goes without saying D- at the alternator and the regulator should be reading zero (well grounded)
From those readings we might be able to figure out where the problem lies.
Don’t know if my meter tests diodes, have to look but I can do the other tests.
61 is the the blue wire from the rectifier to the charging light.
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Using an adjustable VR, 13.2-13.4 volts measured at the battery above 2000 rpm is great....when your headlight is on. Headlight off it'll jump to 14.3-14.5 about
What kind of wattage are you running in the headlight?
I found an extra 3/4 volt by adding a second ground off the diode board, along with cleaning and smearing all the grounds..it seemed to be a never ending search
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Using an adjustable VR, 13.2-13.4 volts measured at the battery above 2000 rpm is great....when your headlight is on. Headlight off it'll jump to 14.3-14.5 about
What kind of wattage are you running in the headlight?
I found an extra 3/4 volt by adding a second ground off the diode board, along with cleaning and smearing all the grounds..it seemed to be a never ending search
I’m not getting those kind of readings, headlight off will get 13.2 but it goes to 12.5 or something like that with the headlight on. Stock headlight and I have two grounds for the rectifier one to the frame which has been there all along and I ran another directly to the battery.
The new adjustable voltage regulator doesn’t increase when adjusted if that is any help.
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Have you checked AC output to to the 3 yellow wires? From memory :rolleyes: it should be around 45VAC at 4K rpm or so.
The important thing is they are all the same between 1-2, 1-3, 2-3. If so, I'm betting on the diode board.
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Have you checked AC output to to the 3 yellow wires? From memory :rolleyes: it should be around 45VAC at 4K rpm or so.
The important thing is they are all the same between 1-2, 1-3, 2-3. If so, I'm betting on the diode board.
I haven’t checked the 3 wires but will check tomorrow. I did put the meter on the large spade of the rectifier and revved up the engine. The readings were all over the place, it did reach 14.1 at one point and everything in between but wouldn’t run up to 14.1 again after the initial attempt.
I will check the rest of the items Roy mentioned, but I do have a brand new rectifier and I’m thinking that I should install it to rule out the existing rectifier. Can’t hurt.
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As soon as I read that the adjustable regulator wasn't adjusting I thoght the issue may be there BC....swapping that out has to be a good check.
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Installed the new rectifier and 14.1 volts, but I’m not calling it fixed until I give it a few days as I’ve been down this road before.
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Installed the new rectifier and 14.1 volts, but I’m not calling it fixed until I give it a few days as I’ve been down this road before.
That's looking more like it.
Perhaps a diode dropped in the old one?
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That's looking more like it.
Perhaps a diode dropped in the old one?
Yes one of the 3 small ones limiting the power available to excite the rotor.
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Grrrr.....no more 14.1.
I may just throw in the towel and buy the EnDuralast system, though I really don’t want to spend $500 bucks on this bike.
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If the rotor resistance is lower than specified won't the output always be somewhat low? That guy from Cycle Electric wised me up to that once.
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Most meters aren't very accurate in the range we're looking at here. If it reads generally in the ball park, that's about the best you can hope for.
What's it charging at now?
The test for the regulator is bypassing it. Pull the three terminal plug and jumper the two leads that aren't the ground. Start up the engine, slowly rev it and watch the meter. Once it gets to mid 14V, back off. The voltage will continue rising the higher the RPMs.
If it doesn't make it up past 14.0, then it's either the rotor, stator or diode board. The most common failure is the rotor. The windings can short together resulting in a weak magnetic field and less voltage generated. Rotors can pass a static test, but fail dynamically. Sometimes it's best to have a known good spare to swap.
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Well, if you would just do what I tole ya and check AC voltage on the 3 yella wires.. :evil: :smiley: you can tell whether the alternator is alternatin properly. :grin: If it is, it's probably the diode board.
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Most meters aren't very accurate in the range we're looking at here. If it reads generally in the ball park, that's about the best you can hope for.
What's it charging at now?
The test for the regulator is bypassing it. Pull the three terminal plug and jumper the two leads that aren't the ground. Start up the engine, slowly rev it and watch the meter. Once it gets to mid 14V, back off. The voltage will continue rising the higher the RPMs.
If it doesn't make it up past 14.0, then it's either the rotor, stator or diode board. The most common failure is the rotor. The windings can short together resulting in a weak magnetic field and less voltage generated. Rotors can pass a static test, but fail dynamically. Sometimes it's best to have a known good spare to swap.
When I checked it yesterday, it was charging in the high 12’s, which is weird considering it was 14.1 when I installed the new rectifier. I’m going to install a new battery tomorrow to make sure that isn’t an issue. If that is not the problem, I’ll order a new rotor on Monday.
“Well, if you would just do what I tole ya and check AC voltage on the 3 yella wires.. :evil: :smiley: you can tell whether the alternator is alternatin properly. :grin: If it is, it's probably the diode board.”
It was easier to install the new rectifier than cranking the engine up to 4,000 rpm multiple times given my location. BUT, I will try that today and report back.
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So you've replaced the diode board and regulator - problem persists. Could be the rotor - it is the most common failure after all.
The battery. I recall a charging thread on Adventure Rider in the airheads section that went on for ever. I want to say sixty or seventy pages. In the end it was the battery.
Some of the simplest things can cause the most trouble.
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So you've replaced the diode board and regulator - problem persists. Could be the rotor - it is the most common failure after all.
The battery. I recall a charging thread on Adventure Rider in the airheads section that went on for ever. I want to say sixty or seventy pages. In the end it was the battery.
Some of the simplest things can cause the most trouble.
I don’t think it is the battery because I’ve installed this new loaner battery once before with the same results, but that was before I made all these changes. Just want to rule it out before I order the rotor.
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I'm with Chuck on this
First thing that should be done before commencing any checks is charge the battery up let it sit for a couple of hours then measure the resting voltage it should be around 13.5 from memory, certainly above 13.
Voltage checks are meaningless if you don't know for sure the battery is completely charged as it will just pull the whole system down.
The way I do it, which is not to say it's the best, is check the alternator as mentioned by measurring open cicrcuit voltage. If it's not doing it's thing then full field flash it and try again.
Once that's all ruled out you can move onto the reg/rec
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Can’t you full field it with a 12v jumper to the DF+ while it is running to see what the max output is?
First you mite as well check the ac side like Chuck suggested
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Ok, charging to 13.20.
Battery is fully charged to 13.5
Pulled the plug to the voltage regulator and it’s about 12.
Did as Chuck recommended and I’m not anywhere close to 45VAC, but I could easily not be doing that right. I set the meter to AC colts and took the reading.
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So what was it? They should be pretty equal between 1-2 1-3 2-3. I'm pretty sure the 45VAC is right at 4K, but haven't found it with a quick search. I'd think at least 40 volts. If it's very low, it's either the rotor (most common failure) or stator. No need spending money <snapping suspenders> unnecessarily.
I'll look for a source.
Edit:
Found this in my "Guzzi stuff" files..
1-2, 1-3, 2-3. At around 3-4k you should be seeing something like 30-40V AC but whatever the figure, it should be the same on all the phases.
Edit again:
Googling shows 40VAC to be a common number from an alternator.
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Chuckie beat me to it, yeah I'd think at least 30 but more like 40 I've never seen a factory figure as they suggest you load check it (like really practical NOT!!)
All I have to add is
If that's not doing the business full field flash as described by John A and try again.
If either of these test are satisfactory the alternator is good.
If you had to field flash to get a reading then possibly the Voltage regulator isn't doing it's thing or the brushes or the connections for the excitation
All I got for now
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With my meter set to volts A/C:
1-2: 12.7
1-3: 12.9
2-3: 10.9
Tach cable broke so this is an assumption of 4K
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The best test of a battery is a load test. You can get a load tester at Harbor Freight. I've been told they're good. But why buy one when you've got a good load right there on the bike? Watch the volt meter (hooked to the battery terminals) while cranking. It shouldn't drop below ten volts if I recall correctly.
I've never taken an AC reading off the alternator - I ought to just for the experience. And to know what to expect.
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These are strange readings BC
Normally it works or it doesn't
Did you try to Full field it and test?
John
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These are strange readings BC
Normally it works or it doesn't
Did you try to Full field it and test?
John
John, I maybe completely wrong as to my meter setting, but I put the dial on Volts and change it from DC to AC:
(https://i.ibb.co/ggSdw5q/F971-C3-D8-9-D69-44-D8-882-A-BD5-A1-B2-ED342.jpg)
No, didn’t try testing it at Volts DC, but I will do that this morning.
WS, I’ll try the load test as you described, but I don’t think it is the battery.
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You either have a bad meter or a bad alternator. <shrug> I'm betting on the alternator.
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You either have a bad meter or a bad alternator. <shrug> I'm betting on the alternator.
I’ll try another meter today. Hmmm....MG Cycle no longer sells alternators, I’ll try cleaning it again and hunt for another source.
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BC
No not DC Volts
The meter does look right to me, and it would apear that it Auto Ranges
When I said full field flashing that is jumping a 12VDC wire (perhaps from the battery) to the DF on the Alternator
If you then conduct the test again and nothing changes then it looks like your alternator is defective. Again you should be measuring AC Volts not DC. If you measure DC it will read next to nothing
That and what Chuck said
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I’ll try another meter today. Hmmm....MG Cycle no longer sells alternators, I’ll try cleaning it again and hunt for another source.
There's no need to spend money unnecessarily. <snapping suspenders, chomping on corncob pipe.> It'll either be the rotor (most likely) or the stator. You've already checked the brushes, etc.
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Had this problem on my CX a couple of years ago...it was the rotor and got a new one from MG.
This engine likes to eat rotors as being on the end of the crank has a tough life.
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Had this problem on my CX a couple of years ago...it was the rotor and got a new one from MG.
This engine likes to eat rotors as being on the end of the crank has a tough life.
Hard acceleration and deceleration eventually works the windings loose, then it's downhill from there.
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I'm curious if the meter was auto ranging and the reading is in KV?
I wonder why, when flashing the rotor, the engine should be running?
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Did the flash, went for a long ride, mostly local roads without too much stop and go with the headlight on and when I came back the battery was at 13.4. When I get back home, will check it again then make up my mind about getting a new rotor. This one is about 10-12 years old?
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I'm curious if the meter was auto ranging and the reading is in KV?
I wonder why, when flashing the rotor, the engine should be running?
BC did say that he was getting around the 12 Volt mark AC on the phases, so I think the picture taken was with the meter at 0 Volts and that's just pic up/drift
What I was getting at was not to try remagnetize the field but to give the field max welly, that way the alternator is going to get plenty excitation, so BC would know for sure if the fault was with the Alternator
Just testing O/C voltage will not distinguish a fault in the Alternator from a faulty regulator which could be opening the excitation.
With an O/C test he also wont blow the bulbs or frry the battery which he could if it was connected up to the rest of the bike
So my reasoning is if the turny bit gets no straight electricity which means the magnet doesn't get magnety which means the stoppy bit can't make any squiggly electricity
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Very nice technical description.. :grin: :boozing:
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After market alternators.
Have a read here
https://bmwmotorcycletech.info/AftrMrktAlt.htm
Yes hes a beemer rider, yes its applicable to guzzi in that these system will fit.
Interesting data on outputs.
Also on his web site is a very in depth trouble shooting guide.
Worth the read.
I used this web site and guzziology when trying to find out why my electron pump wasnt pumping even though EVERYTHING had continuity, the correct resistences, operating diodes and minimal wear on rotating contact surfaces, I have everything except an output voltage above battery voltage.
What fixed it?
In the end after cleaning every contact, replacing wires, cleaning stators, rectifiers, inventing new swear words, pulling hair etc the only thing left was run a oldering iron over all the solder joints on the stator.
The bloody thing worked after that.
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Yeah, that’s a keeper.
“So my reasoning is if the turny bit gets no straight electricity which means the magnet doesn't get magnety which means the stoppy bit can't make any squiggly electricity.”
I give up, just going to order a rotor and then a stator if that doesn’t work.
https://bmwmotorcycletech.info/AftrMrktAlt.htm
Will read this over in case I missed something. Obviously I’m no electrical wizard, so if it’s all new parts and it works then so be it.
And I road the 60 miles home in stop and go NYC traffic, 12.4 with the headlights on as needed.
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It was standard practice to "flash" a generator to create a magnetic field in the iron bits. This residual magnetism was enough to start the generating process when the generator was spun up to proper RPM.
Never flashed an alternator as it is not necessary or beneficial. The alternator rotor is supplied an initial current fed through and limited by the dash charge indicator lamp. This current supplied is enough to induce a magnetic field at the rotor. The magnetic field passing through the field windings (stator) causes them to put out a current flow. At this point the regulator takes over and supplies current to the rotor at a level to produce the desired output from the field.
That's why it takes extra RPM to put out the idiot light on initial startup (because the idiot light doesn't pass much current). Subsequent excitation is supplied by the system output which has a much higher potential.
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When you apply 12v to the field ,marked DF+,you are bypassing the regulator and she puts out everything it can find. You prolly have a semi retired rotor. Just a guess mind you. Could be the smoke leaked out as well.
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Just to finish this up. I received the new rotor from MG Cycle, installed it and it charged up to 14.1 volts but the dash light was still glowing at idle rpms, then last Friday the Domino ignition/kill switch smoked out. There was some mysterious issues when revving up the engine which I could never narrow down until now.
Anyway, until I get a replacement switch which is in route and a replacement switch harness from Greg Bender, I have jury rigged the wiring so I can start the bike via the starter. The interesting thing is that the charging light goes off immediately now and I don’t see it at idle. Now I’m wondering if this switch was the problem all along though I can’t say why, but I might re-install the old rotor before it’s tossed just to make sure it is in fact bad.
Thanks all.
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the claw on your rotor has twisted, there should be gaps between the poles, sorry for the late response but you can see that rotor is bad from the photograph, the metal poles are touching, and that is shorting out the magnetic field lines and weakening the field which reduces your output.
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the claw on your rotor has twisted, there should be gaps between the poles, sorry for the late response but you can see that rotor is bad from the photograph, the metal poles are touching, and that is shorting out the magnetic field lines and weakening the field which reduces your output.
Claw?
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Claw, the outer iron pole piece
They should be equally spaced, not touching their mate. Can't beleve we all missed that.
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Claw, the outer iron pole piece
They should be equally spaced, not touching their mate. Can't beleve we all missed that.
Oh....OK.
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This is a "clawpole" rotor, The steel "pole" pieces look like claws if you imaging the rotor disassembled so you would have the shaft, two steel "claws" the copper coil and the slip rings as separate pieces. the individual steel teeth should not touch each other when the rotor is assembled, they should be equally spaced. one of them has twisted so the steel pieces are touching, that is bad.
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(https://i.ibb.co/9v4TwLM/E5-B5-C992-70-B2-474-D-AA7-E-52588-E832072.jpg)
http://www.mgcycle.com/index.php?main_page=product_info&cPath=37_161&products_id=760
Now I understand after looking at my old one compared to the new one. Wow, how does that happen? Heat?
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Press fit assembly. Maybe someone grabbed an out of tolerance part and built your rotor. I assume it never dragged on the stator?
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Press fit assembly. Maybe someone grabbed an out of tolerance part and built your rotor. I assume it never dragged on the stator?
As I posted early on, it sort of wobbled.
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That's a new one on me...geez
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I wonder if you can fix it by forcing the poles apart and gluing it in place, if it moves easily then maybe it wasn't a good interference fit, I don't know if they rely on the impregnation to hold it in place. If it "failed" then obviously at some point it has moved. How did you stop the crank rotating while you tightened the alternator bolt? Not that it should really matter but if the rotor was weak to start with?
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I've never seen that before either.
Usually the rotors fail due to changes in inertia. The speeding up and slowing down causes the wire to shift and eventually wear through the insulating shorting it out, or rubbing against the steel and breaking. I've wanted to take one apart, but from descriptions of how they're built it sounded daunting. Yours would probably come apart fairly easily, unfortunately. Good thing it's been removed before it did some major physical damage!
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First for me too, no idea how they are assmebled, guessing I'd have thought an interference fit or better a taper
Thanks BC you've taught me something new and something else to look for
John
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Thanks BC you've taught me something new and something else to look for
John
John, That’s funny.
I haven’t had a chance to play with the rotor and see if it moves, but at this point I consider it toast. In terms of tightening it down, I’ve always just tightened it without putting the engine in gear.
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BMW Specs for the same rotor bolt are 14 ft/lb with dry, burr free taper. I put bike into gear and set rear brake to tighten bolt.