WHAT A GOOD CHARGING SYSTEM LOOKS LIKE
On (NOT running)
I installed a voltmeter onto my bike to be sure I knew what
was going on. There are other ways to achieve this. A circuit
to light GREEN when the battery is charging and RED when the
battery discharging would be good. There are commercial version
of this available for about $40. The voltmeter above is made
by TELEX. Its a cool piece because it was made for watercraft
and so is waterproof. AND... Telex is selling off this line so
if you can find one in your marine stores they going for about
$25 now (9/2002).
What should a good charging system look like on the Vision.
Well, there it is above. Little over 14 volts when running and
the battery needs charging. And unless you're doing long rides....
the battery always needs charging.
What Goes Bad and Why
Click For The BIG Picture
Charging systems have typical failures, and some more common
than others depending on how well built they are. Here are the
- Stator Winding failure
- One of those 3 wires in the stator as broken internally or
(worse) has shorted to the engine and ground. This is most typical
because the stator is exposed to a lot of heat and vibration
inside the engine. Wire insulation also decays over time. Lastly,
if the regulator fails or the current draw from the bike is too
great (bad battery or bad corroded connections) the stator wiring
and connections can begin to melt over time. You will see melted
plugs and scorched stator bodies when this happens. Lost phases
will decrease AC (and DC) output. And/or shorted wires can fry
the stator and regulator too.
- Rectifier failure
- The rectifier uses 6 diodes arranged to "chop"
the AC output from the stator to DC current. The DC is conditioned
a little bit more with capacitors, etc... since "rectified"
AC is still a little "choppy" and not good for newer
LCD microchip driven displays and other solid state devices.
Needless to say, if the diodes burn out you have problems. Depending
which diodes go the DC voltage output can be lower to nonexistent
- Regulator failure
- Less likely but possible is that regulator circuitry fails
and the output will be too little or too much. Too little and
the battery eventually dies. Too much and the battery will overheat,
bubble over and self-destruct.
- Heat Disappation
- There is a VARIETY of discussion about the stator and/or
rectifier overheating and failing:
- The stator is cooled by the oil under the crankcase. If the
oil is allowed to get low then the stator can potentially overheat
- The rectifier does not charge the battery all the time. If
the battery is full up then the rectifier will "SHUNT"
the electric pulse from the stator back to ground. In laymans
terms ... "SHUNT" basically means the white wires are
grounded. The stator pulse goes nowhere. This is not exactly
what's happenning but close (DON'T GROUND THE WHITE WIRES!).
When this happens the electronics in the Rectifier are handling
the excess power and things get hot. That's why it has heat fins
- WHAT DO I BELIEVE ??
Hey.. since I wrote this I get editorial
I personally believe most everyone's charging problems
stem from either a bad battery, low oil or MOST IMPORTANTLY
bad connections on the bike. ANY bad connection on the bike induce
voltage drops acroos the charging circuit that overheat every
component in it. It will melt the WHITE 3-wire stator connector
(VERY TYPICAL), and ultimately overheat the STATOR and Rectifier.
A bad battery will overtax the charging circuit and melt it.
These are some myths concerning charging systems and
here are a couple:
- Bad connections in the charging system wiring causes a "voltage
drop" across the wiring. This in turn causes an increase
in current draw from the generator. The extra power going to
bad connection is converted to heat. The heat produced in either
the stator or rectifier causes a failure. You might see the signs
of melted plugs and wires or heat deformation on stator or rectifier
- The battery itself is causing the heavy current draw mentioned
above. This could be a bad battery -or- a drained battery that
you are charging with the motorcycle charging system. People
often associate charging system failures with "jumping"
a battery. Its not the jump that did it most likely (unless you
hook the cables up backwards which instantly fries the rectifier
usually). The problem is that your motorcycle charging system
is not heavy duty enough to charge a dead or bad battery.
- Crappy components. The truth is the Vision stator is cheaply
built. The stator wiring fails. Also, both the stator and regulator
could be cooled better for durability. Any way you look at it
the system tends to fail prematurely.
Preventive Measures For The Yamaha Vision charging
- "Jumping starting will damage your system"
Done correctly .... untrue. If you jump a dead
battery that is not good (will not hold a charge) the charging
system may carry a heavier load for longer than it was designed
for. Remember the Vision system is "rated" in a perfect
world for 20amps ... but NOT for the next 2 hours. Add
to that some bad connections, headlights, the stereo and A/c
(I'm kidding here), and .... you get my point. You may overheat
and ultimately fry some part of the system (stators , regulator,
both...). If you jump the battery with the cables reversed you
will also cream the system (most probably the regulator).
- "Disconnect one of the 3 stator circuit wires will
help the stator run cooler and last longer because there is less
unused electricity flowing through the system"
This actually sounds good in theory. No, really. But......
untrue. Don't take my word for it. Call any knowledgeable
shop in the world please. And, really, if this were true this
technique would be used on every generator in the world and quite
clearly it is not, so_ooooo.....
- "Magnets never go bad"
Sort of ....untrue. Magnetism is a nebulous thing
(how often do you get to use that word) and from grade school
science you should remember that iron magnets tend to lose strength
with vibration and heat. Where are those stator magnets again?
How often is this a problem. RARE. About as rare as a spark coil
going bad. BUT, it is possible and should not be totally left
out of your thinking. I had an alternator rewound twice for a
car that never quite put out a great solid voltage when loaded
up to its rated amp output. What's left that can be wrong? Crappy
magnets. Remember in a motorcycle (unlike an all-parts-in-one
alternator) your charging parts (stator, magnets, regulator)
are all separate pieces.
Unless you buy and install a newer aftermarket stator and
regulator (see ELECT REX link below) you can't make it a "better"
system. So, the trick is to make what you have bullet proof.
Here are the tricks recommended by
others lifted verbatim from
the Vision Forum archives.
Repair and Maintenance of The Yamaha Vision
- Make all connections in the charging system clean and protected.
Solder wires to their respected plug pin ends. Use WD-40. Use
dielectric grease on the outside to "water-proof" connectors.
Using plain simple common wheel bearing grease, put a light coating
of grease in the internal areas of the stator coil connector.
An even better permanent fix would be to clip off the male and
female components of the connector and hard wire/solder the connections.
The wires are white in color on both sides of the connection
so it's not critical which ones are soldered together as long
as a bike wiring harness wire is connected to a stator wire.
If for some reason this connection needs to be broken in the
future, simply cut the soldered wires and then resolder them
Electrical system operation:
The V alternator puts out 100% of its capacity ability all the
time, given the RPM it is operating at. What the bike load doesn't
use is shunted to ground by the regulator. The connector carries
whatever amps the alternator is putting out all the time regardless
of bike load. Low Rpm = low amp output = low amps passing through
connector= electrical needs deficiency made up by battery. High
RPM=max amp output=max amps passing through connector=amperage
left over after bike load is serviced is shunted to ground. Note
that is both cases all amps pass through the connector before
any electrical distribution or alteration is done. The alternator
always puts out the most it can no matter what is happening down
stream. Therefore, the connector is always passing (or attempting
to pass) the max amps available.
The way the problem develops:
When the connector is rendered inefficient due to corrosion the
alternator continues to put out all the amperage it can. It doesn't
know or care about the condition of any of the electrical components
that follow after it. It just stays busy doing its thing. However,
since the connector is now not able to pass through 100% of the
energy going into it, it passes what it can and the rest of the
energy backs up in two places and defaults into heat at both
places. One place is the connector itself and the other is the
alternator stator coil. The heat in the connector melts the connector
plastic which turns all gunky and greasy and nasty and generally
adds to the connectors' ineffeincy which in turn compounds the
problem. The heat in the stator coil melts the coils' insulation
which eventually fails and allows the energy the coil creates
to go to ground via the engine cover that the coil mounts on.
That is why the test for a failed coiled looks for continuity
between any one of the stators' 3 coils (accessed through the
3 white output wires in the stator side of the connector) and
ground (the engine). Continuity indicating a failed stator coil.
Don't forget to please not loose track of where the problem originated,
namely corrosion within the stator connector. The Big Clue here
is the condition of the connector. A melted nasty connector got
that way from heat. Where did the heat come from, inside or outside
the connector? If inside, what was the source?
The way I see it you have two options. 1. Clip off the female
and male halves of the connector and then solder each former
female wire to a former male wire. Of course, each resulting
soldered joint must be individually insulated. It doesn't matter
which former males are soldered to which former females. All
the wires on each side of the connection are white. This what
I have done and it has served me very well for the last six years
even under extreme heat and load(130/100 watt headlight bulb)situations.
The only usual reason to use the connector is replace the stator
coil. That problem is now fixed and the side left engine side
cover shouldn't need removal for a very long time. When that
time comes, simply clip the soldered connections and then resolder
them upon reassembly. 2. If you are paranoid about clipping off
the connector and it is still serviceable, clean the connector
pins and sockets to bright and shiny condition and then apply
a thin film of common non metallic wheel bearing grease to all
metal connector surfaces. Then reconnect as usual. This process
forms a vapor barrier that keeps air borne water away from the
connector metal, thereby inhibiting corrosion formation.
- Make sure you have and keep a good battery. You can use a
multi meter to measure the amp draw on the battery after starting.
With lights off it shouldn't be more than about 5 amps (if that).
Much more and you have some problem going on there.
- "The stator rotor is coated. Definitely don't damage
it with steel wool. It produces an electrical field with the
stator, and should be left alone. "
Get and Use A repair book !!
The following discussions have been copied verbatim from rider
messages on the Vision forum. They concern repair or replacement
of the Stator under the left crankcase cover. In short, you
must carefully seal the crankcase cover back to the engine or
you will have dreaded oil leak. This is particularly important
around the stator and spark pickup wires which exit the crankcase
Stator Wires exiting crankcase cover pictured on left.
- Yamabond #4 by Dan
1) Go to Yamaha dealer and obtain a tube of Yamabond #4...nothing
else(including Permatex#2) is quite like it as far as tenacity
2) Take left cover off again, clean ALL old goo out thoroughly.
3) Using fine sandpaper, clean carefully ALL aluminum surfaces
that the grommets come in
contact with ...every stinking edge...until bright shiny and
4) Clean ALL old goo off of every bit of the grommets themselves...and
5)Run a thick ring of Yamabond around both grommets, and directly
on the wires where they pass through the grommets...work the
wires in and out of the holes a bit to ensure the sealants coating
6) Wait about ten minutes for the Yamabond to set up a bit.
7) Smush the grommets back into the slots they belong in...carefully
place a NEW gasket onto the left side of engine case, and re-assemble.
8) Wait 12 hrs if you can before refilling with oil to make sure
the stuff sets up well. NO LEAKS SO FAR IN DOING THIS TWICE THIS
WAY AFTER 4 PREVIOUS ATTEMPTS TO SOLVE SAME LEAK.
- Charge cures by bernard lajoie
source a re-wind from "Rick's Stator"(west coast)or
Cycletronics(use to be"Willy's")in Alabama(east coast).
For reg./rect.replacement,throw the yamaha part in trash,go to
salvage yard,use either Honda or Kaw. For Honda use cm-400/450
twin or cx-500/650twin only! Wire in this order,3 yellows to
stator(one per leg)red w/white to battery pos.,small black wire
to (switched HOT)this is the volt reg.wire. If not hooked up
bike will over charge(16-19volts,not a good thing). Last hook
green wire to battery ground. Some Honda reg./rect. will have
(2)red w/wht@(2)green just splice together(red to red,grn to
grn). For Kaw.use late model kz/zx 550,kz/zx750,kz/zx 1000/1100(these
are the 2-valve motors,zx=GPZ)or 600r(ninja)4-valve,wire in this
order,3 yellows to stator(one per leg)white w/red to battery
pos.,brown(smallwire)to(switched HOT). This is reg./rect.wire,black
to battery ground(IMPORTANT:you will need the gang plug that
plugs into reg./rect.w/2-3in of wire to wire correctly I.E.cut
from main harness as nessary,sometimes the salvage guys don't
like this). Your bike will now email@example.com,also ck.battery
pos.&ground cables,these are prone to fail.
- Removal tips by QBS
Regarding removal of the three Phillips Head screws (and for
that matter, all Phillips Head screws in general) that attach
the stator coil to the left engine cover: If you don't have an
impact screw driver with a properly sized bit, don't touch them
until you do.
Specific to the V: after the left engine cover is off, lay it
on its' side, outside down, on a wooden surface. Then use the
impact driver and hammer to loosen the three screws. Reattchment
with the impact driver is the reverse, being carefull to not
over tighten the the screws. First tighten the screws as tight
as you can by hand. Then give them one or two (Max!) impact driver
blows. who it might be that may have to remove them in the future.
Another tip: If you haven't got an impact driver, or the screw
heads are too trashed to be of any use, but you do have a little
room to work with around the screw head area: Use the smallest
Vise Grips you can get and grab the screw head very firmly and
attempt to turn the screw head in a counter clockwise direction.
I've used this technique many times over the years and never
fail to get a small thrill of satisfaction everytime I overcome
the challange of a screw head that at one time would have caused
me hours of frustration and grief.
Another tip: If you don't have an impact driver, you can simulate
one using a screw driver and a hammer. Insert the tip of the
screw driver into the screw head, firmly grasp the screw driver
handle and preload the screw in the desired direction of screw
rotation, then hit the head of the screw driver with a stout
hammer blow. This technique can be used for either direction
of screw rotation.
Another tip: A damaged screw head, bolt head, or nut can sometimes
be loosened by using a sharply pointed punch and hammer to rotate
it in the desired direction.
- It's time by QBS
It's time to reattach your starter clutch. Get a Haynes manual.
Remove your stator rotor/flywheel. Remove the three allen screws
that attach the SC to the back of the rotor. Inspect the clutch
rollers for flat spots and replace all damaged rollers. Inspect
the clutch housing for cracks in the roller area. Replace or
repair(weld cracks) housing as necessary. Reassemble and reinstall
SC. When attaching SC to back of rotor, use new allen screws
that protrude 2 or 3 threads beyond the inside surface of the
rotor. Use Loc-Tite on these screws and between the very clean
oil free mating surfaces of the SC and rotor. After the screws
are tightened, pean their protruding threads. Reinstall the rotor
SC assembly. If the future ever requires removal of the SC, grind
the peaned threads level with the surface of the rotor and unscrew
them as usual.
Before final assembly of the left engine cover, do a continuity
check of the stator coil as described in the Haynes manual. If
continuety is found, replace the stator coil. When reassembling
the left engine cover, inspect the stator coil connector for
corrosion related internal heating damage. If found, seriously
consider clipping off the connector and hard wiring (soldering)
the connection. If the connector is still servicable, at the
very least you should lightly grease the inside of the connector.
If you don't, stator coil replacement certainly lies in your
future. If the above SC attachment and stator coil connector
procedures are performed, the left engine cover should not require
removal for many years, if ever again.
After you reattach your SC you'll be amazed at how quite the
engine is at idle. Your information regarding V engine life is
correct. A well maintained V should go at least 100K with no
major internal problems. Mine is working on 73K.
- Flywheel removal by pat sullivan
I recently removed my flywheel to inspect the starter clutch.
I used an impact wrench, and with it I did not have to hold the
flywheel at all. I checked with the local Yamaha shop in Santa
Clara, CA and they indicated that they use pullers for Automotive
Harmonic Balancers that they get from local suppliers. I bought
one of these for around $30 and it worked fine. Later I found
out that you can rent these at several tool supply rental houses.
As indicated earlier in this forum, you have to whack the bolt
on the puller quite hard in addition to using the impact wrench.
I thought for a while I wasn't going to get it off, but eventually
it popped off when I hit it. Put a padded box under the flywheel
while you are doing this to catch the flywheel and the starter
clutch rollers and springs that are likely come out when the
flywheel finally comes off. You'll probably also need a impact
socket to do this. I split my regular socket on the first try.
Took stator flywheel off on december of last year because I needed
to change the roller pins and get the base where those pins go
to welded back as it was cracked. This is how I did:
o Remove left cover
o Put the appropriate size socket + wrench on the flyhweel nut
(a.k.a big nut even though right now I do not remember if it
was a nut or a bolt. Who cares? =)
o Get a bolt like 2-something inches long (a.k.a. small bolt)
and then turn the flywheel (using the wrench on the big nut)
until you can jam the bolt between the bike frame and those holes
that were drilled on the outside of the flywheel for balancing.
The idea is to use the small bolt to stop the flywheel from turning
while you play with the big nut.
o Holding the small bolt, so it will not pop out when there is
no compression load on it, loose the big nut
o Using an adequate puller, take the flywheel off. What I used
was a a 3-bolt puller like the ones used to, say, pull steering
wheels off (something that can be found at your friendly Autozone
or similar store). Now, the 3 bolts where the wrong size and
pitch for my need, so I went to a hardware store that specializes
in nuts and bolts and got 3 bolts (allen, not that it matters)
that would fit on the thread and would be long enough so they
would be in the puller when I threaded them into the 3 flywheel
holes. So, their length really depends on the puller you are
When you are ready to put the bugger back, do remember to align
the flywheel as there is a key/notch arrangement between flywheel
and the conical base where the bit nut is bolted to. Besides
that, use the small bolt to hold the flywheel in place as you
tighten it and you should be home free.
- Voltmeter by Burke Storti
Has any body figured out how to install a volt meter or other
indicator which can tell the
condition of your charging system while the bike is being ridden?
With this, at least we would have some warning that the stator
is "pushing up daisies".
I had a similar experience as Dan. I came home from a 150 mile
ride to discover my battery
was dead when I killed the motor in front of my house & could
not get it to start.
- I have a voltmeter, and some comments on what it shows
by John Logan
I installed a voltmeter, a clock, and an oil pressure gauge across
the dashboard inside my '83's fairing. I glued a hardboard backing
to the thin plastic dash for more support.
The gauges I chose were the "Cockpit" series from VDO.
They match the Vision's instruments,
except that they have blaze orange rather than yellow needles.
They have held up perfectly for
It's a very pretty setup. The wiring for a voltmeter couldn't
be simpler: you just need a hot wire and a ground. One thing
I have found is that the voltage tends to vary in mysterious
ways, even when the stator and regulator are new. Revving the
engine produces a drop in voltage over
certain rpm ranges, even though there is sufficient voltage at
I also have an indicator LED on my TDM 850 that glows green,
yellow or red depending on the
voltage. This too shows strange voltage drops during parts of
the rpm range.
Following the excellent diagnostics given in the electrexusa.com
site, I systematically brought the resistances and voltage drops
in the Vision charging circuit within specs. This helped but
did not completely remove the strange voltage dips with engine
rpm I have always seen with the
The voltmeter is a great help when the stator is failing, since
it gives the warning you need to avoid getting stranded. The
rest of the time it should not be too closely examined.
- Regular voltage check question by QBS
Thank you for an excellent gauge piece. Could one get the same
benefit of impending stator
doom warning by doing a multi meter voltage check across the
battery terminals before the first
ride of the day at say 3500 RPM and keep a mental note of the
reading for future comparison.,
kind of like checking the oil. Battery access is very easy. I
realize this a somewhat of a nuisance
and won't reveal problems that may happen later in the day, but
stators don't seem to fail
catastaphically. Rather, they sort of sneak away and before you
know it they're gone.
- makes sense to me by John Logan
I think your procedure makes sense, but it would be more than
I could ever force myself to do
routinely. For the '83, a voltmeter in the dash is cheap and
easy. Some cost well below $20.
For the '82, I'd recommend the LED type -- it's just a little
button with a glowing bulb in it, and
should be easy to find a spot for. You need a couple of inches
of clear space below the
- Stators Cooling by Mark Moreland
Just found this site. Read a few dozen messages but did not see
a suggestion on stator cooling.
I was an REV member about 1990. I obtained several years newsletters.
One had a tech tip
that suggested adding an oil spray orifice to the bolt in the
oil gallery of the stator end of the crankshaft. I recall the
orifice was drilled at ~.040" dial, and was counter bored
larger to help break up a stream and make the oil sling outwards
to the stator.
Does anybody recall this?
- Red: stator cooling by Chris Arrowroot
I've seen that fix too, but I can't believe spraying hot oil
on the stator would improve its
- Oil Cooled Stators by Dale
The Vision's stator is already oil cooled, but the flow is too
limited or not even, resulting in the over heating at high Ramps.
Increasing the oil flow would help but I have no idea as to how
to make sure that it is flowing (in and back out).
- Possible source for this stator cooling tip
by John Logan
I do not know whether drilling the rotor bolt helps the stator
longevity problem, but I have a
clipping from the March, 1984, issue of Rider Magazine discussing
a similar fix for the Venture, which is very much like a four-cylinder
version of the Vision:
"One of the foremost problems acknowledged by Yamaha has
been stator failure. The
alternator has been running in an insufficient oil bath, which
has caused the stator wires to
overheat and short out. Ours failed at 11,500 miles. Most have
been giving up at around the
8000- to 10,000-mile mark. In order to lower the operating temperature
and increase the
reliability of the AC generator, an improved rotor bolt with
a 0.7 mm [0.0276 inch -- JAB] oil
passage must be installed. This supplies additional oil to the
generator area to cool the rotor and stator. An improved [Venture]
stator has been designed for '84."
I'd be interested to know if anyone has experience with this
type of fix for the Vision or has
examined the improved rotor bolt for the '83 Venture. If the
latter just has a bore through its
center, that should be easy to accomplish. Note that the article's
bore is smaller than the value Mark gave. I would be worried
about effects on oil pressure -- does anyone have information
- response by Jason Morris
Yes the Venture has a hole drilled thou the bolt but it is larger
closer to the crankshaft.A "wire" rests inside the
hole keeping it clean and free from blockage.The hole is only
about 1/64" at the case cover side.This keeps the volume
and pressure high at all times.My '83 venture had the update
and was standard '84 on.But you can't use a Venture bolt,the
size is completely different.You'll need to have your bolt drilled
at a machine shop or do it yourself with a cobalt or titanium
drill bit on a drill press.
- Fix the problem by Jeff Swan
The problem with the stators is the excess heat created by the
corrosion on the connections. The drilled stator bolt was a stop
gap measure by Yamaha when stators started burning up. I guess
they thought they needed more cooling when the problem was the
connection and they knew they couldn't get everyone to clean
the connections. I did this mod to my Vision, but that hole is
welded up now as I have become better informed. I don't feel
it will keep your stator from burning up but will delay the inevitable.
I say keep the oil where it can do it's job ( in the main and
rod bearings) and fix those connections. Use some synthetic oil
for cooler running oil tamps if nothing else.
Cranking amps is the spec that tells you how much current a battery
can produce for 30 seconds at a temperature of 32° F and
not have the voltage on any of the individual cells drop below
1.2 volts (7.2 volts for a 6 cell automotive battery). This may
also be known as MCA or marine cranking amps.
Cold Cranking Amps:
This is the same test as cranking amps but is done at 0°
F. The CCA spec is especially important if you live in a really
cold climate. Since the chemical reaction that produces electrical
current in the battery slows down as the temperature drops, the
battery can produce less current at colder temperatures (especially
below freezing). When comparing the current capacity of batteries,
make sure that you have some standards to qualify the current
ratings. If you see the current rating without CA or CCA, you
don't know how the battery was tested and the current rating
is virtually useless.
The reserve capacity is the time that a battery can produce 25
amps at 80° F before the individual cell voltage drops below
1.75 volts (10.5 volts for a 6 cell automotive battery).
Deep Cycle vs Standard Battery:
A normal lead-acid battery will be damaged if it is completely
drained (even if it's only one time).
A deep cycle battery is designed to survive being drained multiple
times. Deep cycle batteries have more reserve capacity but have
less cranking amps for a given size. A standard battery would
have more total surface area on its plates when compared to a
deep cycle battery of equal size. This extra surface area provides
more area for the chemical reaction to take place and therefore
produce a higher output current.
The electrolyte in a deep cycle will be a slightly more concentrated
sulfuric acid than a standard battery.
These folks were known as Electrex.com. They are the motorcycle stator
guru's. They carry new stators for everything including the Vision at about
$125.00US and have a full one year warranty.
(Except Images and where otherwise noted)
© 1999 David "Leather" Draper
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