If it has an ST-style induction generator head (popular with Chinese gensets), you need some residual magnetism in the rotor to generate enough current to energize the feedback circuit that controls the voltage output. It feeds some of the output voltage back to the rotor to create the magnetic field used to generate power. The power output comes from the stationary coils in the housing, not the rotor. If it's been sitting for years or you let the rotor spin down while under load, you will lose the residual magnetism. If you apply load before it's up to speed you can dissipate the magnetic field and you get no output. Either way, the solution is to apply 12V to the rotor for just a fraction of a second to magnetise it, then start it up with no load. Polarity does not matter. Just make sure you are applying voltage on the rotor side of the regulation circuit, or remove the plate and use two alligator clip leads connected directly to the brushes. If you don't see a little spark when you magnetize the rotor, then something is wrong and you might want to check with an ohmMeter to make sure the brushes are making contact. You should only have a few ohms of resistance. The same thing happens if you way overload it when it's running. You usually won't burn it out, it just stops creating current.
Some of the genheads have 2 sets of rings (4 total). If that is the case, look at the connections to see which two are wired in parallel. Apply voltage across the ones not wired together. -Dave Walton On 9/15/07, Jim Cathey <[EMAIL PROTECTED]> wrote: > First I checked the oil. It had some. Next I checked the battery, it > was dead and drew no charging current. I went and got a car battery > and a set of jumper cables and hooked it up. The key then worked, but > the engine only turned over a few times before it 'stalled'. I pulled > the end cover off the housing and spun the motor back so the starter > could get a 'run' at it, then it turned over again. It cranked a lot > but no fire. There wasn't much fuel in the tank. I poured in the 2 > gallons I had in a can and cranked again. (Sometimes I had to roll > the motor backwards again.) Eventually it started firing > intermittently, and with more cranking and running attempts it finally > got up 'on plane' and ran. Not all that noisy, even with the covers > off. > > Once it had run a few times it started easily with the key. I'm sure > being warm helped, as did getting all the air purged from the fuel > system. The set takes a long time to spin down when turned off. > There's a spring-loaded red lever behind the access hatch that applies > throttle. If you hit the release lever it drops to, or below, idle > and stops. There is also a red lever on top that I don't know the > purpose of. It can only be accessed with the box's end cover taken > off. > > There is no voltage output, either AC or DC. I checked the wiring and > such inside the cabinet, and there were no obvious faults or burned > items. The regulator is potted, so that's not very handy. There is > an exposed power diode bridge, but it checks out OK. There are no > specs or schematics that I can find, I'm not sure where to look next. > There's an odd heat-sinked box separate from the regulator that hooks > to a pair of green wires that come out of the flywheel area. It has > an inline fuse hooked to it, which I checked. Also good. There are a > lot of wires. > > It's a mystery. Perhaps I've just purchased a one-lunged diesel motor > for $400? Still not a bad deal! > > When I took the big battery off I found that the little one was now > taking a charge. We'll see if it recovers enough to be usable. It, > not fully charged, wasn't (yet) able to fight the engine's compression > enough to turn over. > > -- Jim > > > _______________________________________ > http://www.okiebenz.com > For new parts see official list sponsor: http://www.buymbparts.com/ > For used parts email [EMAIL PROTECTED] > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
