Two different R27 problems! [Archive]

millerph

11-19-2010, 08:18 AM

20774

11-19-2010, 09:03 AM

Paul -

Welcome! Good speeds on that R27. I've been seeing speeds of 90 on my R25/2...ummmm, 90 kph that is!!

As for the carb issue, you might want to look at the advance unit...it may be sticking open. Plus, you might have the carb slide sticking as well. Sounds to me like you might need to overhaul the carb. Have you done that with this bike?

RE: generator light, the brushes might be hanging up and/or are too short. Take a look at them. There's a small spring that is supposed to push them down against the commutator. RatShack makes a spray that is good for electrical circuits. It's a cleaner and lubricant...might be worth a try.

James.A

11-19-2010, 09:09 AM

1) regarding the idle.
Make sure there are no vaccum leaks anywhere on the Carburetor or the intake downstream from the carb. Pay particular attention to the top of the carb where the throttle cable goes in. There is a small o-ring under the threaded collar that holds the top together. Next, make sure that your centrifugal advance it proprerly functioning. When I did mine, I lubricated the pivot points and installed new springs. When you have eliminated vacuum leaks and confirmed the function of the advance mechanism, you will want to adjust for a desireable warm idle, and then LIVE WITH THAT. It's an antique machine. There is no choke or enricher to compensate The air fuel mixture for cold operation. This was one of the hardest things to accept when I was campaigning one. I learned to let the dang thing warm up a little before a took off, manipulating the throttle to keep it running until it stabilized. Also I had retro-fitted a type 53 carb from an r50/5. That carb has an accelerator pump in the main jet stack. I later discovered that my R27 had a carburetor originally fitted to an R26 on it when I brought it home. The type 53 carb solved all my fuel mixture issues.

2) electrical issue.
The red light indicates a charging failure. This seems at odds with your need to replenish the battery acid. That is always an indication of over charging and a malfunctioning voltage regulator. If your battery is not fully charged, the light can glow at low idle speed because the generator it'self is not producing the minimun out put to activate the regulator. If your light came on at highway speed, that suggests an abrupt change of the function of the voltage regulator to me.
These things can be taken apart and contacts cleaned. If you had a service manual you could test for continuity of the windings.

I no longer have mine, having sold it with the bike last year.

millerph

11-20-2010, 05:42 PM

Thanks Guys, very good ideas! The carb air leaks were (are?) an issue, exactly as described and I plan to rebuild this winter. Today I found a crack in the expansion joint just in front of the carb, so that is another thing to replace...

Each little fix is noticeable, so I'm having fun!

Cheers,
Paul

85K100LT

11-30-2010, 11:54 AM

DarrylRi

11-30-2010, 12:00 PM

1. Get a spray bottle of gas and spray it around carb to see if engine idle increases due to sucking in gas/ identify any air leaks. Be careful to not get to much sprayed around to avoid fires.

2. use a DVM ( Digital Volt Meter) to check battery voltage with bike not running should be around 12.8V. Then start Bike and check voltage at idle and at higer RPM to see if there is higher voltage/ battery is chargeing.

:bikes

Don't spray gas around the running bike, it's very dangerous. Use WD-40 or something like that.

These bikes are 6V not 12V. You should see something like 6.6V when the battery is charging (well above idle).

1074

12-06-2010, 01:41 PM

Hi,

After many years of wanting one (mostly emotional, certainly not logical!) I purchased a 1966 R27 this summer. Lot's of fun and brings me back to simpler times. When I first got it the top speed was about 50. After plugging some air leaks in the fuel system, running carb cleaner, new spark plug wires and adjusting the carb that is up to about 70.

Two problems that have me a little unsure:

- when the bike is cold and I adjust the idle stop in idles nicely, but when hot the idle is up around 4000 rpm. I can adjust the idle back down and it runs smoothly, but it means that I'm constantly adjusting the idle stop with engine temperature.

- while riding down the freeway last night the red light came on. Over the next 15 miles home the lights got dimmer and dimmer and were barely lit for the last 5 miles. The bike ran fine otherwise. I've been having to add water to the battery most every time I ride it. Perhaps the voltage regulator or coil?

Thanks for any tips!

All the best,
Paul

The idle, mixture ans speed, should be adjusted on a warm engine.
Definitely a charging problem. Always start your troubleshooting with a good, fully charged battery. Measure voltage across the battery. Start the engine and rev it up while measuring the voltage. It should climb. Check it with the lights on high beam as well. If it goes over 7.5 or 8 volts, then it's most likely the voltage regulator. these bikes are not known for their superior lighting.

millerph

02-12-2011, 08:14 PM

Hi,

A follow up to my earlier posts. I ordered the carb rebuild kit from Bing and spent a couple evenings taking it apart, soaking it, cleaning it and putting it back together. Only one extra part!! It is some sort of rubber cable cover but doesn't show up on any of the diagrams or pictures of the bike so I'm not too worried.

I greased the advance, put the carb back on, wrestled the tank on (why it doesn't fit around the seat will be another issue to solve) and the bike jumped to life on the third kick and is running great. I had an enjoyable 30 minute ride around the neighborhood today. There were a few weeps that I had to tighten some of the smaller machine screws to eliminate, but it looks like the fuel system woes are at least temporarily solved.

So, now back to the charging issue. The red light stays on and no voltage increase is seen at the battery. Unlike what the shop manual says, if I pull the ground off the battery when over 2500 rpm, the bike stops. The new Rhino SLA 6V 9AH battery has all the lights going brightly. I checked all the grounds I could find for looseness or corrosion. I cleaned the brushes and made sure the springs are holding them tight against the commutator. They are about 5/8" long. I replaced the voltage regulator. I've ordered a new condenser.

I tried repolarizing. No luck with the red light issue, but I did get a spark, which I think was a good sign. In a fit of cleaning frenzy I took some cleaner and wiped down the commutator. The rag came away quite black and now instead of a bright red light, at higher rpm the light dims just a bit.

So, the advice given on the carbs was spot on, what is a good next thing to try on the charging?!

Cheers,
Paul

20774

02-12-2011, 08:31 PM

Since the R27 is a battery-coil ignition system, you can't pull the ground for the battery and expect it to run. A good battery and ground is needed. The magneto systems (R60/2, R69S) don't need a battery to run.

Condensor won't have any effect on the charging...it's part of the ignition system.

I reread your first post, and it sounds like the charger was working initially but then the red light came on. That means that the wiring was OK at some point.

Something must gone bad in the wiring. If the regulator is new, then that can't be it. Maybe you've lost the commuator...IIRC the various contacts are interconnected by all the wiring. Possibly some part of the wiring has shorted or gone open.

I think you're going to have to do some tracing of the wiring. That's going to require a good wiring diagram. Vech at Bench Mark Works sells a book by Doug Rinckes that provides a lot of detail and troubleshooting tips.

ccolwell

02-13-2011, 08:55 AM

BTW, my tank doesn't clear the seat either.

20774

02-13-2011, 10:55 AM

If the charge light burns bright all the time, it looks like the regulator is not functioning properly or is not adjusted correctly. What type of replacement regulator did you use? I understand that a solid state regulator is probably the way to go.

On my R25/2, I have to undo the seat spring to pull the front of the seat back a bit. Then, with some coaxing, the tank will come off.

millerph

02-13-2011, 01:53 PM

Hi,

Yes, it was very sudden when it stopped working. I was riding down I-97 at about 7 o'clock at night (in the fast lane with commute traffic) when suddenly the charge light came on. The lights immediately basically went out. That was kind of exciting.

I was checking the wiring and leads this morning. I don't know if it is significant, but if I put a voltmeter from the "9 o'clock" brush and rev it up I get about 1.7 V to the blue wire. From the "12o'clock" brush I get about 0.6 V.
http://www.flickr.com/photos/roundel/331109632/in/set-72157594434937833/

My commutator is very black around the path the brushes travel vs the clean copper in the picture. Perhaps a thorough cleaning of the commutator...

The regulator I put in is a mechanical Bosch, new construction but looks just like the old ones. The electronic one available from Bob's was definitely not a plug and play and I didn't want to fool around with that.

As I understand it the regulator is supposed to open to allow the current through when the voltage from the generator gets to 6.5V-6.8V plus. The blue wire is the one going to the regulator from the generator and since I'm only getting 1.7V, the regulator will not switch on to let the current to the battery. That is, if the generator puts out 6-8 V instead of a different value with a stepper.

According to the shop manual the bike should run with the battery ground lead disconnected if the generator is putting out a high enough voltage for the regulator to open. The wiring diagram shows that the circuit is then open from the generator to the coil.

Cheers,
Paul

20774

02-13-2011, 02:05 PM

According to the shop manual the bike should run with the battery ground lead disconnected if the generator is putting out a high enough voltage for the regulator to open. The wiring diagram shows that the circuit is then open from the generator to the coil.

Paul -

That is news to me. It is my understanding that a battery-coil ignition system must have the battery in the circuit in order for the R27 to run. It should be the same as my R25/2. Several months ago, I was running along just fine...generator working just great. The bike quit on me. I pushed the bike to the side of the road and began to look around. A bad crimp on my battery ground lead came apart. Once crimped back together, I was on my way again. Without the battery ground, the bike didn't run.

20774

02-13-2011, 06:46 PM

Are your brushes making good contact with the armature? The small snail springs are supposed to provide adequate pressure on the brushes. If the brushes get too short, the spring may hang up on the brush holder and not put pressure on them.

I notice you linked to Allan Atherton's photo of the alternator. Do you have one of your own? How does it compare to Allan's photo?

millerph

02-13-2011, 07:11 PM

Hi,

Mine looks basically identical to Alan's other than the color of the brushes and commutator, and his is generally "fresher". His looks shiny copper, mine is quite black. I'm not sure that there is a good connection there between the commutator and brushes.

I took the inner plate off and cleaned and brushed everything I could find. There was some grease and corrosion on the field coil plates and the armature stainless plates. I cleaned the wire ends and put it all back together. Now when it is revved I get about 6.2 V at the blue wire and the charge light dims. Some progress!

The brushes seem to sit nicely, but they are about a 1/4" shorter than Alan's.

According to the shop manual, to get the bike started you either need juice in the battery or the ability to get it rolling quick enough to bump it, with the battery disconnected.

My guess is that some extra resistance somewhere is causing a voltage drop. I think when I get the new brushes I will take it back apart, trace each wire, clean them all and put it back together. I will also put in the new condenser. There are also a couple grounds buried deeper I can clean.

We'll see...

Thanks,
Paul

20774

02-15-2011, 06:46 AM

According to the shop manual, to get the bike started you either need juice in the battery or the ability to get it rolling quick enough to bump it, with the battery disconnected.

I'm still having trouble grasping this. It's been my understanding that w/o a battery, the bike won't start. The ignition system on the R27 is not that different than my /7.

However, after exchanging some thoughts with members on a German forum, it does sound like the bike can be started without a battery. However from what I can tell, you must get the engine spinning quite fast, well over 1K RPM and keep it there. If the RPMs drop, the bike will die.

I think this relies on the residual magnetism in the armature. Without this and without sufficient engine speed, I think it would be nearly impossible to start and keep a bike running without a battery.

millerph

02-15-2011, 07:54 PM

Hi Kurt,

That is basically what the shop manual says. To start it by bump starting you will need to have the engine spinning above 1800 rpm, if the generator is working well. That is supposedly the point where the generator is supplying more juice than the battery and the regulator lets the generator send the juice to the coil and the battery. Below that rpm the generator is putting out too little and the battery feeds the coil through the regulator.

An interesting, simple idea that I'm glad is not on my newer bikes!

Thanks for looking it up!

Cheers,
Paul

20774

02-18-2011, 07:52 AM

I was directed to a section in my R25/2 repair manual for troubleshooting the dynamo. For one of the tests, it says to get the engine running at around 2500 rpm and turn on the head light. Then disconnect the battery ground. Removing the ground should result in slight brightening of the light and restoring the ground should slightly dim the light. I guess the test is to confirm that the generator is actually working.

So, I guess the bike can run without the battery in the circuit. Starting it might be kind of sporty, but looks like it will run without the battery as long as the RPM is kept up.

millerph

02-21-2011, 05:24 PM

Well, I put the new brushes in and thoroughly cleaned the commutator and all the connections inside the generator housing. The charging light got quite a bit dimmer, almost going out at full rpm. Checking the voltage I'm getting up to 6.4 V at the blue and red wires versus ground (DF and 61).

So, while it is better, it is not good enough!

I took the seat off so I can take the tank off without screwing up the seat (again). Next is to check the connections at the new voltage regulator. I think the problem is in the generator however as it really should be putting out closer to 7.4 instead of 6.4.

Is there a way to test the armature? Any other thoughts?

Cheers,
Paul

20774

02-21-2011, 05:46 PM

Paul -

I don't recall...have you cleaned the armature, especially the slots between each set of contacts? I can't seem to find information on the R27 winding measurements. I would check the resistance between adjacent contacts...it should be fairly low. Also, each contact should be very high with respect to the iron core.

millerph

02-21-2011, 07:16 PM

Hi Kurt,

I did a thorough cleaning such that it looks like Alan's picture. Good idea on the resistance checks, I will do that (fourth time taking out the field coil plate!).

I also found on the 6V VW forum a check for the generator output. You basically disconnect the generator from the regulator and run the generator separately. Theoretically without the regulator it should read about 17V. It turns out that a bad regulator can keep the voltage too low by restricting the current. The VW forum showed a drawing of their Bosch regulator and it looks a lot like the R27's. They do mention that the electronic regulators may solve that problem as they can correct a wider range of voltage/current issues.

Now that the seat is off I will lift the tank off to clean the regulator contacts first and check that wiring for continuity. Sounds like enough to keep my evenings busy this week!

I will also get a chance to replace the aluminum trim around the seat.

Thanks again for your help!

Cheers,
Paul

ragtoplvr

02-22-2011, 02:30 PM

In general terms, since I do not know R27

The best way to test a generator is to run it as a motor. If a generator will not motor, it will not generate.

To do this you need to apply 6V and ground to the case, and then you have the fields to excite. There are 3 common fields. A circuit, where the field connects to ground, B cir suit where the field connects to 6V and isolated, where you have to connect the fields outside. Polarity is critical.
The generator with the fields connected will motor at a slow speed, if you remove the field connection it will briefly speed up then stop.

The mechanical regulator can be changed with as little as a 1 foot drop. You have to let one run for 15 minutes with the cover on before checking the voltage, as these have bi metal strips and copper wire, all of which change with temp.

Normally to adjust the voltage you bend the spring seat up or down to change the voltage.

These time consuming steps are often omitted in today's hurried world.

Rod

millerph

02-24-2011, 06:27 AM

Hi Rod,

Neat idea! I will try to figure out how to do that!

Cheers,
Paul

copandengr

02-28-2011, 05:47 PM

The armature can easily be checked with an ohmmeter. Any given commutater segment should have continuity with the segment that is 180 degrees away. There should be no continuity between any segment and any other part of the armature, nor should there be any continuity between any segment and any other segment that is NOT 180 degrees away from the segment in question. There are only two possibilities with an armature winding as far as failure goes... They will either fail open, or in other words have a broken winding, or they will fail by shorting the winding or segment to the armature body

Weak brush soprings will allow the brushes to bounce on the commutator and allow arcing. This is seen by the black streaks on the copper. An out of true armature will also cause the bouncing as will worn out bushings.

Any good starter/ alternator/ generator shop can rewind an armature, or if needed repair the commutator. It might not be all that cheap to do, but depending on how scarce this generator is the cost could be justified.

One last thing.... On a high mileage generator it is common to have a densely packed build-up of carbon between the segments of the commutator, and there can also be copper dust there also... either will short the segments out and cause failure... When a commutator is turned down during a rebuild, the insulating material between the segments must be undercut to inhibit the ability of copper buildup across the segments as well as preventing arcing bewteen segments during normal operation. Again, this is an easy thing to do for a properly equipped shop. The average Joe can do it by very carefully using a thin hacksaw blade.

millerph

03-06-2011, 06:46 PM

The entire armature/commutator is very clean and there is no grease or build ups. The gap between the commutator parts is clean and the insulation between the stainless parts of the armature is clean. The commutator is shiny copper.

But, every one of the armature stainless plates has continuity to every other part. Also, every segment of the commutator has continuity to every other segment. There is no continuity between any of the commutator plates and any of the armature plates.

44006

03-10-2011, 07:14 PM

"11-19-2010, 08:18 AM
- while riding down the freeway last night the red light came on. Over the next 15 miles home the lights got dimmer and dimmer and were barely lit for the last 5 miles. The bike ran fine otherwise. I've been having to add water to the battery most every time I ride it."

Above sounds like generator was overcharging to the point the armature windings got hot enough internally to melt the lacquer or other coating on the windings and short them together resulting in the following:

"03-06-2011, 06:46 PM
every segment of the commutator has continuity to every other segment"

This was a common occurance with Harley Sprint 1965-1972+- which was guaranteed to cook its generator with sustained interstate 70mph operation.
The generator of the sprint is very like the generator in my R26 BMW and maybe same or very close to same Bosh armature

A fellow I used to ride with who rode BMW R26 in the late 1960's would not sustain speed over 60mph for any length of time - not because of electrics - but because he swore it always would lead to conrod big end failure - he had rebuilt several times.

millerph

03-16-2011, 08:32 PM

Could be overcooking. I thought that would be controlled by the voltage regulator but after replacing it to no effect and after talking with Benchmarks and Motorad Electric it might be an internal armature short. Interestingly, on my last check I was getting 4.9-5 v consistently from the generator. As the voltage is a function of the current and the windings, a short in the windings would cause the lower voltage.

Apparently a good test can be done with a growler, which I don't have. Bob's does however, so I took it over there today. We'll see!

If it is a bad armature the options seem to be:
new armature for $440
new generator for $1063
switch to a 12v system for $575

Any opinions?!

Thanks,
Paul

20774

03-17-2011, 05:37 AM

I would want to stay 6v but sometimes finances needs to be factored in.

ccolwell

03-17-2011, 06:13 AM

I think the only reason to keep it a 6v is originality. That might make a difference in resale value, but I doubt much. I'd go with 12v, but then I like triple disk brakes.:D

44006

03-19-2011, 08:34 PM

"Could be overcooking. I thought that would be controlled by the voltage regulator but after replacing it to no effect .........."

Quite likely bad regulator system at first produced the overcharge/overload which burnt the armature up before you replaced the regulator. If one of these old relecs was cranking out
enough charge current to boil out the battery repeatedly it almost certainly toasted itself. I
have never been blessed with such an excess of charge current on any vintage machine.

If you have the person with a growler and he knows how to use it that will probably tell the tale.

If the 12 volt system you mention is like the 200 watt alternator that is sold for /2 it is wonderful
simple and easy to install and will run quality h4 light and electric vest. Expensive headlight
reflector conversion though and if stand on the rear brake in traffic too long will melt tail light
lense.

When I was buying these armatures (bosh) for HD Sprints in the late 1960,s they were $35
from a BMW dealer and $60 from a Harley dealer.

millerph

03-30-2011, 08:01 PM

The latest update...!
Took it to Bob's for testing on the growler. Came through that test fine. They then traced the wires and found nothing. On a hunch that the problem may only show up when spinning they borrowed another R27 armature (thank you whoever that was!), put it in my bike and it charged fine!
They have now ordered an armature. Fingers crossed.

millerph

05-22-2011, 05:25 PM

Good news - bad news

The Good - The new armature showed up from Germany after only two months. It went in fine and all seemed great...!

The Bad - 250 miles later,oOn the way back from the Classic British and European Bikes rally in Clarksburg today the charge light came on, went off, came on, went off, ..., stayed on. Got it back home, put the voltmeter on the battery and got 4.6 volts with the engine running at about 1500 rpm and 5.7 volts with the engine off.

So, going back to the beginning, there were two symptoms. The dry battery and the charge light. Is something causing the armature and battery to go bad? I did put in a new voltage regulator early in the attempts to remedy.

20774

05-22-2011, 05:38 PM

Ho boy...back to the beginning. The Rinckes book doesn't seem to cover something like this. You really must have something basically wrong or something is ruining things when you get new parts. Kind of beyond my DC circuit expertise...my next call would be to Vech.

millerph

06-18-2011, 05:03 AM

Hi,

What I'm hoping is the final post on the problem!

Not wanting to void the new armature's warranty, I took it back to Bob's. They confirmed the problem and put the armature back on the growler, no problems seen.

Dave checked through the various electrical parts and found that the wire to one of the brushes had fatigued and was actually broken, although it looked connected. Due to its stiffness and construction it would connect when at rest, but would move apart when the bike was moving. Since it was new, it was under warranty.

Fingers crossed, the bike runs great again. Hit 70 mph on the way home!

Cheers,
Paul

millerph

01-31-2012, 07:42 PM

Another update; the problem is not yet resolved. The joy of an old bike. So, the new brushes lasted about 15 miles and the red light was back on. The service guys and I brainstormed to no avail.

Off I went to the MOA Rally and visits to the Vintage area and Airhead tents. 30 seconds of listening at the Airhead tent and Bill suggested it was probably armature out of roundness due to crankshaft wobble. Sure enough, I got home, borrowed a dial gauge and found the armature was 15 thousands out of round while the BMW spec was 4. Some guys are just really good! Off the crankshaft the armature was only 3 out of round. It took a few months before I had the time, but I set the bike up with the gage in place and filed the stainless strips until I got the out of roundness to 5. Unfortunately I couldn't get it closer with the set up I had.

I reassembled the bike, rolled it outside, found the battery was at 6.3V and started it up. The red light was still on! I then checked the voltage and found that one brush was not getting a contact. I lightly pushed the brush down and bingo, the red light went out! Woo hoo!

No problems for about thirteen miles. The red light stayed off, the bike ran and I was feeling good. Then the bike shuddered like it was low on electricity. I quickly flipped the lights out, it perked up and I rode home. The voltmeter showed 5.1 V.

I figured I really needed to see what was going on electrically so I bought and installed a WattsUp at the battery. It tells me voltage, current and power. With the engine off and the lights on there is a draw of about 43 watts from the battery. With the engine running at about 1500 rpm with the lights on, the red light is out, the voltage is 7.1 and the draw is about 38 watts. So, it seems the "50 Watt" generator is putting out the voltage but not more than 5-10 watts.

Any thoughts from the collective?! Try again to get it under 4 thousands?

Thanks in advance!

Cheers,
Paul

20774

02-01-2012, 05:50 AM

Paul -

Sorry, but I'm really at a loss on this. But you went from 15 thou to 5 thou with basically no improvements, right? You still lost power or battery charging in about 15 minutes. So going to 4 thou doesn't seem like it's going to really result in any improvement.

You must live close to Bloomsburg? Do you live in PA? I know Tom Cutter doesn't work on these bikes. Todd Byrum is the Airhead Airmarshall...he might have some ideas. The Airheads site has a file showing Airhead friendly shops around the country. Maybe someone on that list has some experience with pre '70 6-volt electronics.

69zeff65

02-01-2012, 08:10 AM

Give your entire wiring harness a once or twice over. Check for kinks, pinches and potential breaks or partial breaks in your charging system wires especially. A simple continuity test with an ohm meter may or may not show problems so a really really good visual and finger manipulation check may reveal the culprit, a couple pinched or broken strands can really make a difference with old wires and components. Make sure you have excellent grounds and connections in the entire system also. I had an R 26 that did the same thing but it was the Harley shop rebuilt(not trued up very well) crank shaft that caused that problem so long ago, so you may have already found the problem but don't know it. You may also consider taking your charging components and putting them an the test bike

44006

02-01-2012, 08:49 PM

"With the engine off and the lights on there is a draw of about 43 watts from the battery. With the engine running at about 1500 rpm with the lights on, the red light is out, the voltage is 7.1 and the draw is about 38 watts. So, it seems the "50 Watt" generator is putting out the voltage but not more than 5-10 watts."
=====================================
I think your conclusion is wrong - if voltage is up to 7.1 when running at speed the 6v battery is being charged. There is no other way to view this. You are not understanding your measuring gadget.

You need to connect a needle type voltage meter to the battery(not anywhere else in the harness) and get it up to the handlebars or tank bag so you can see what the voltage does when you actually ride.
Make sure the voltmeter is reading voltage and not vibration when you are running.

If your battery is going dead while riding there will be a significant period of time where the volt meter is showing significantly less than 6v or showing wild fluctuations in voltage.

You mention you had to push one of the brushes down to get charge current started(red light go out) - you may need to sand off some of the brush thickness or width so it freely rises and falls within the brush holder to compensate for the out of round condition of the armature.

Another thought - is there any evidence that the outside of the armature is rubbing the field shoes? - this would heat things up and kill the charge current.

Just to be sure we are all understanding each other:

Armature is the entire unit affixed to the end of the crankshaft
Commutator is the segmented ring of contacts upon which the brushes ride

The armature can be out of round relative to the crank quite a bit and still work so long as it does not rub on the field shoes.
Filing down the outside of an armature that does not touch the field shoes will just reduce the magnetic field and therefor the ultimate output.
The commutator needs to be nearly true relative to the brushes so the brushes do not bounce - back in the day of auto generators we used to sometimes spin the generator and turn down the commutator so the brushes would not bounce and then undercut the grooves between the segments - it would not matter whether the shaft was true or bent so long as the commutator end was true

Report back

millerph

02-02-2012, 08:43 PM

Hi,

My bad, I was using the term armature and commutator incorrectly. There may be some armature rubbing on the field coils as one shows a bit of brightness compared to the others. The out-of-round-measurements were for the commutator. If there is rubbing on the field coil, do I file down the stainless piece?

Regarding current versus voltage, the WattsUp reports Volts, Amps, Watts, Peak Amp, Peak Watt, Amp-hr and Watt-hr. The way I have it rigged up is that the meter is taped to the handlebar crossbar and it is in the electrical system right next to the battery. No error on the amount of current flowing to/from the battery.

I do believe that filing the commutator down did make some improvement as the red light now stays off (since I pushed the brush down). I will file the brush to make sure it slides more easily - it did feel a bit sticky.

Thanks again!
Paul

44006

02-03-2012, 08:14 PM

The armature must not rub on the field coil shoes - I think the way to solve this is not to file on the armature but to loosen the bolts holding the field assembly SLIGHTLY and tap this assembly with a plastic mallet or piece of wood till is does not rub and then re tighten - you can trial and error this with a smear of thin paint or other material and see if it rubs off or not and then know which way to knock the assembly to improve the situation. Whatever you do - do not run this thing rubbing against the field you will destroy the new very expensive armature.

As for your measuring gadget I am not familiar with it but voltage at the battery while running is the only thing you need to look at and sometimes digital meters are not good at detecting fluctuating voltage - some do not read at all and some seem to average things out and not clue you into an irregular fluctuating voltage like an old fashioned needle voltmeter does. I don't know what the WattsUp is but if it is digital it may not be useful for this problem.

The voltmeter you use does not need to be accurate but just indicate that the voltage while running is reasonably more than the voltage of the charged battery at rest.

A cheap needle type voltmeter will usually show if the problem is wild fluctuations in voltage caused by jumping brushes and will also show when the voltage regulator changes the field current by its switching resistance - you can usually see this cutoff and determine if it is reasonable.

I am making a rather wild guess here but I suspect if you are starting out as you have previously said with a charged battery and an initial good charge rate from the generator and then end up down the road with a dead boiled out battery the following is happening:

1) on starting out the system is working properly
2) on running for some time the jumping and sticking brushes are fooling the regulator into always switching for max charge rate and overcharge battery
3) rubbing armature on pole shoes overheats the field and armature and or the brushes stick and charge rate declines from heat or no field current from brushes
4) then you are running on battery alone till it is discharged

Do not loose sight of the logic that must apply here

You cannot "boil/dry out" the battery without applying an excessive charge rate/voltage - there is no other way - so the generator will charge and do the job but is being prevented from doing so in a smooth and regulated way probably by mechanical problems with the brushes or regulator or a buildup of heat sufficient to degrade the electrical efficiency of the unit

file or sand down BOTH brushes till they work easily and smoothly up and down the brush guides