Engine runs great, but no ac power

The motor will run hot when the brushes are worn. If the scooter is used daily and runs a lot, brushes could be the problem. They are not difficult to replace.

If the unit is equipped with a voltage regulator or a bridge
rectifier, flash the field as follows:
• Obtain a 12VDC battery.
• Get two jumper leads that can go from the battery to
the brushes (wires with alligator clips work well).
• Find the brushes inside the alternator portion of the
unit.
• Start the engine and get it up to running speed.
• Connect the battery positive (+), to the positive brush,
which will be the brush closest to the rotor bearing.
• Connect the battery negative (-), to the negative brush,
which is the brush farthest away from the rotor
bearing.
• After about five seconds, disconnect the battery wires
from the brushes and check for proper (AC) output
voltage.
• Shut the engine down. Restart the unit and check once
again for proper (AC) output voltage.

These rigs are notorious for developing bad connections in switches and wiring, as well as getting stuck or burnt brushes in the generator. If it has been sitting for some time, I would definitely do maintenance on the brushes and check switches for rusty or burnt contacts. http://www.millerwelds.com/om/o175104b.pdf

Drive belt may not have adequate tension, motor brushes may be worn out, tread tension may be too tight, one or more of the control devices may have failed, the power to the treadmill is inadequate.

Drive belt can be viewed with the motor cover removed. If it slips, adjust tension until static belt delfection is about 1/8 inch.

If motor halts with load and belt does not slip, adjust the tread tension by turning the track tension bolts counter clockwise 1/4 turn at a time, both adjusters evenly. If no improvement 1 full turn in, check motor and or control board.

if tread adjustment does not help, check the brushes to make sure they are not hanging up in the holder. Remove the plastic caps that retain the brush inthe motor with treadmill unplugged, If they are 1/4 inch in length or shorter- replace brushes. If the motor does not have brushes, it is an AC type motor.

If brushes are fine, check motor voltage with an analog voltmeter- AC range if you have the open frame AC type of motor where you can see the windings (no brushes) and measure voltage on theboard terminals that go to motor. They should adjust from zero to at least 80 volts via the speed control knob. If the AC motor hums a great deal, replace the motor run capacitor.

If you have the DC motor, (usually about the size of a 1 liter bottle.), Check voltage range, it should have the same voltage range as above with meter set to DC range.

If in either case the motor moves fine, but full speed on control does not yield full motor speed, check the devices, usually SCR or Triacs on the AC motor type and MOSFETS or IGBT on the DC motor types.

Site unseen i would say its neighter the brushes or the coil . And more the likely the problem is with a transformer converting the DC off the generater to AC for your output . If the engine runs ok and the armature in the generater spins ok and you don;t have a million hours on it should work at least somewhat . Try testing the output on the AC side see what you get for AMPS you will need a muilty meter set to AC amps

engine starts & runs but no power.checked breakers ,theyre not tripped

next is...brushes..
if they were fine check AVR

don't hesitate to write to me for further information:
[email protected]

generac was purchased by Briggs Stratton some years ago, however some information is available at the following web address, just enter your model number:

http://www.generac-portables.com/service_support/owner_manuals/owner_manuals.cfm

The small board that you describe is the bridge rectifier that converts ac from the windings to dc for the armature. You can test the brush/board by removing the part from the generator and applying 12 to 16 volts ac to the input tabs/wires then test/read dc (dc voltage will be lower than input ) voltage at the brushes. Use meter to make sure that you are getting dc. I use a small power supply less than one amp that I purchased at the thrift store for a couple of dollars. If test fails replace part. If it tests ok re-install brushes and re-connect the ac power supply to brush/board which in turn will energize the armature. At this point test the armatrue for magnetic power. I use a thin welding rod or wire against armature. If you feel a magnet start the engine. If the windings are good you should get some voltage at the plugs and the two wires that feed the brushes (will not be full voltage). If voltage is present, kill engine and disconnect ac power supply and connect the original wires to brushes/board and start engine. If you now have voltage at plugs you spiked the system indirectly by energising the armature. If still no voltage you may have an open circuit that feeds the brushes or diode pack is failing with the incresased voltage. Good luck with your repair and email if you have questions.

To flash the excitor circuit on a coleman ( the generator is built by generac) you need a 12 volt battery. You quickly apply 12 volts via your 120vac recepticals. NO MORE THAN ONE OR TWO SECONDS! Then check you ac voltage. Most of the time the brushes are burnt up when voltage is low. Check the brushes first. You can access them by taking the end cap off of the generator via two to four screws. The brush holder is easy to spot, two wires leading to the front of the amature. Hope this solves your problem.

Here is a simple test to check field and other wiring. With engine off apply 12v ac 1 amp to 110v outlet plug on generator. This will energize the field windings and should cause the armature to produce dc voltage at the brushes and produce a nice magnet. If there is a short in the field or broken wire or shorted capacitor there will be no dc reading at the brushes. . This test is the opposite of what actually occurs when the engine is running. That is the armature produces a magnet fed thru the windings, regulator and brushes. If dc voltage is present at the burshes, remove 12v ac and start engine to check for output. enjoy