My rectifier loss AC output - Motorcycles

https://www.allaboutcircuits.com/textbook/direct-current/chpt-14/electromagnetic-induction/
The AC power changes the magnetic field and may be being picked up in your amplified leads .

Or the DC voltage in your amps power supply is not filtering the power after it rectifies the AC power .A really big capacitor across the dc voltage output from the rectifier should filter any AC out.
https://www.allaboutcircuits.com/textbook/experiments/chpt-5/rectifier-filter-circuit/

Static electricity...

Generally considered a nuisance... can cause serious damage to electronic equipment... (it is STORED power)

Thunder & lightening are STATIC electricity...

Wiki definition included (below)

For commercially available ELECTRICITY...
(usa) "currents" ... All electricity functions because of a DIFFERENCE in potential. When you start adding wires then you are harnessing that potential DIFFERENCE into usable energy.

Direct current & Alternating current... Generally referred to as "AC" & "DC"

Most all of the power grid you are looking at on power poles around your community... have "AC" flowing on the power wires
good for powering residential housing and commercial power applications

Immediately below those wires ... The phone wires
have to run about 10 feet below the "AC" wires...
Phone systems run on "DC" because it is quiet
(communications systems).

Alternating CURRENT can be rectified into Direct...
and Direct CURRENT can be inverted into Alternating.

Generators, solar panels & BATTERIES output DC
Which can be accumulated and stored.

Alternators output AC... and because AC is less susceptible to magnetic interference... it can travel great distances with very little loss.

Very interesting topic for further research ... and the principals of both... as argued by no less than Nicola Tesla & Thomas Edison.

Hope this helps

Static electricity

Carnac the Magnificent

It may not be a problem with the rectifier!
IF you are using a AC voltmeter to check your AC input, you need to remember that the function of the rectifier is to convert the AC wave to DC. Are you checking the output voltage on the DC scale?? If you have no DC output you need to check the connections of the rectifier first, but there is a circuit breaker after
the rectifier but before the cable exits the case. The breaker usually fails before the rectifier, unless the charger got wet, which allowed corrosion on the connections.

all the operator can ck on this if ckt breaker is closed on genset panel , this controls output power to all the outlets on genset , if that's not to be found as cause then a qualified serviceman will be needed to further diagnose problem

Check the stator for AC output to the charge rectifier, if present stator ok, then check DC on DC side of rectifier if not present change the rectifier, ssuming all fuses have been tested

Check the AC mains rectifier dides/ [stalk]. Replace the main filter capacitor. Rectifier bridge. Rectifier diode at secondary voltage. Filter capacitor for secondary rectifed voltage.

yes it could be

check your battery 1st , then check the stator a/c output

• 10 or 16 Amps DC regulated for charging
battery
• Two black leads (C) from stator
• Yellow connector (D) with two pin
terminals
• Two yellow leads (E) to regulator-rectifier
(F)
• One red lead (B) from regulator-rectifier
to red connector output lead (A)
• 10 and 16 Amp systems use the same
stator, color coding and regulator-rectifier
• Alternator output is determined by the
flywheel alternator magnet size


The stator and regulator-rectifier are the same
for the 10 and 16 Amp systems. The system
output is determined by the flywheel magnet
size.
Test Alternator Output
1. Temporarily disconnect stator wire
harness from the regulator-rectifier.
2. Insert RED test lead (A, Figure 28) into the
V ω receptacle in the meter.
3. Insert BLACK test lead (B) into COM
receptacle.
4. Rotate selector to AC Volts position.
5. Insert RED (A) and BLACK (B) test lead
probes into output terminals (D & E) in
YELLOW connector (C). (Test clip leads
may be attached to either terminal).
6. With the engine running at 3600 rpm, the
output should be no less than:
• 20 volts - 10 Amp System
• 30 volts - 16 Amp System
7. If No or Low output is found, check for
bare wires or other defects. If wiring
defects are not found, replace the stator.
voltage depending on alternator type and magnet size

then check the regulator / rectifier , make sure it is grounded properly

make sure battery earth lead is good

i suspect loss of bat voltage is letting the afterfire solenoid close off the main jet

let me know model and type codes off engine & i will try help further

cheers

By ac you mean receptacles, not ac welding? 
If so what about welding output on AC (DC)?

If welding is OK then you may have breaker or fuse problem.
If welding output is also low or no output your problem is the generator.
You should check your gen rpm to be normal. If so you may have field problem: rectifier, AVR etc.
If you can measure the field DC voltage at rated rpm, if it is missing (very low) try to find any circuit broken.
If you do not succeed answer this instruction in order to give you more.

What is the type (input, output, power) of the rectifier.
If controllable - may be the control PCB or thyristor.
If not controllable - 10 V DC instead of 230 V DC is hardly believable.
In this case the rectifier may be OK, but the input - low.
If you have a voltmeter, check the input AC and the output DC if the output has about 200 V AC you may have shortened diode.

You need to check the fuses first with a continuity tester then the 12v DC out at the edge of the PCB, if you can read 12vdc then you have a component failure if not then the rectifier has popped.

(The AC transformer supplies an AC output of say 16v and it is then rectified and smoothed before going to the pcb)

If you have had the same backup battery in for more than 3 years it may have popped that circuit