Re: Gasket
- From: "Albrecht via MotorcycleKB.com" <u33665@uwe>
- Date: Sun, 06 May 2007 20:40:38 GMT
Broderick Crawford wrote:
Well my next project will be to change out the regulator/rectifier. Any
tips?
Now that I know the generator is intact I want it to put to be 14
to 15 volts at 5000 rpm instead of 12 to 13. I get a net loss during a
riding day and have to charge at night or eventually the battery will be
too weak to start it. I don't know what else it could be.
Save your money until you are sure it's the RR. Screwzuki probably wants $300
for an original equipment RR, and Electrosport will want over $100 for an
aftermarket RR.
Do not change the RR until you test it properly. It's not a real regulator,
it's a SHUNT type regulator that grounds out one phase of the stator and that
cuts the generator's output power in half.
The rectifier part of the RR changes AC into DC by means of six diodes inside.
If any one of the six diodes is blown out, you will lose 1/4 of the charging
power of the generator. If two diodes are blown out, you will lose1/2 the
power of the generator and the battery won't charge.
Got an ohm meter?
The way to check the diodes is to use an ohm meter and check from any one of
the three AC input phases on the regulator itself to the power output lead.
If you don't get the same low reading (say 12 ohms or less) from any phase
input wire to the DC power output pin reverse your ohm meter leads and try
again.
(A red wire or a wire with a red stripe will probably be the power output in
the wire harnes, so you can use that for a guide to the RR's pinout. The
ground wire will probably be black or green or be white with a black stripe.
The three AC insput wires are probably all the same color.)
Then, if all three diodes read the same, check from each of the three phase
inputs to the ground wire of the rectifier case. Again, the readings of the
OTHER three diodes should all be the same.
I can't tell you exactly what the readings will be, because the internal
battery of your ohm meter will bias the diodes and affect the reading.
The way to test the stator is to connect your ohm meter across any two of the
three AC outpout leads. You will get the same low ohm reading (maybe 1 to 3
ohms across each pair of leads on the Rx1 scale. Then go to the Rx1000 scale
and check the three output leads to the engine case.
If you get no reading from one phase to the other 2 phases, the stator has an
open winding.
You should read over 500,000 ohms from the leads to the crankcase. If you get
a lower reading to the crankcase, the stator is shorted
You cannot test the charging voltage unless you have a fully charged battery
in good condition.
If you have a good battery, and the six diodes are all okay, you can run the
engine up to about 3000 RPM and watch the voltage regulating function in
action. As the RPM comes up, voltage will rise from 13.0 volts or thereabouts
and it will drop off suddenly to about 13.0 volts after it reaches 14.5 to 15.
0 volts (approximately)
Then, when you roll off the throttle, and roll it on again, the voltage will
rise to 14.5 or 15.0 volts and fall off again, over and over and over,
everytime yo turn the throttle up and down.
You have a permanent magnet alternator. As long as the permanent magnet rotor
is turning, and the three phases of the stator are OK, it will put out as
much as 100 to 150 volts AC from phase to phase to phase with the stator
disconnected from the wiring harness.
Is the rotor turning when the engine is running? If the bolt that holds the
rotor onto the crankshaft gets
loose and allows the rotor to walk around on the end of the crankshaft, the
woodruff key will break and chew up the end of the crankshaft and you will be
very unhappy.
The open circuit voltage test is only done for just long enough to see if all
three phases are producing AC voltage. Each phase normally returns power to
the next phase in rotation A to B to C.
If you get power from A to B and switch leads and don't get any reading from
B to C, then C phase is shorted out or open and you'll need a new stator.
DO NOT ride your motorcycle with the phase leads disconnected, you can burn
out a perfectly good stator.
You may be wondering why your generator only puts out 12.0 to 13.0 volts when
the generator leads are all connected to the motorcycle wiring harness.
The generator is actually fairly weak, it only puts out about 400 watts and
the motorcycle lighting system burns up about 100 watts. A discharged battery
may suck up 150 watts.
But what happens if the battery is old and sulfated and only uses 15 watts or
less to charge itself?
The excess power heats up all the electrical connectors and melts them. The
hotter the connectors get, the more they melt and the worse they get.
You need to go through the entire charging system and examine all the plastic
connectors for melting, discoloration, or corrosion. The three phase leads
from the alternator may be in a square plastic connector that is obviously
melted, or they may be bullet connectors which have plastic insulation.
If the insulation is getting too hot because of a poor connection, it will
turn brown or black.
If you have melted, discolored connections, the voltage regulator never works
to shunt excess voltage
to ground.
--
Message posted via MotorcycleKB.com
http://www.motorcyclekb.com/Uwe/Forums.aspx/tech/200705/1
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- References:
- Gasket
- From: Broderick Crawford
- Re: Gasket
- From: OH-
- Re: Gasket
- From: Albrecht via MotorcycleKB.com
- Re: Gasket
- From: Broderick Crawford
- Gasket
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