Generator repair

[Ryder]

I have about 35 years experience working in various shops repairing motorcycles, 4 wheelers and portable generators. I would be glad to share fix it tips. Like why does my generator start but then surge or die out? I am currently riding a motorcycle that goes 60 MPH and gets 75 to 100 MPG and I bought it on craigslist for $125.00.

[opsec]

Glad to have you as a resource for this. I just had a burning question that is right in your field of expertise. From what I can gather, you have 3 basic choices of fuel for generators. They come as gas, diesel, or propane powered. I have heard that the gas powered ones have the shortest productime lifetime, the diesels have a longer life expectancy and are easier to repair, and the propane generators have the most longevity. Is that true?

[Publius]

Ryder may say different, but my experience has been diesel, with a qualifier. One of the problems with the stuff you can buy at Home Depot is that it is a two pole generator, so the engine hase to run wide open, 3600 RPMs to keep the 60Hz requirement of our appliances. This would be true of any fuel you use with a two pole. Now a four pole generator would allow a cut back to 1800 RPMs, or a bigger engine running even slower, but that would require the generator head to be separate from the engine and geared so that the generator part is doing 1800 like these engines http://www.listeroid.com/ This one has a small video and IMO real cool. http://www.poweranand.com/default.htm Now when you start talking about these type of diesel gen sets that are 5-10 K you aren't going to pay $500-$1000 for them. They are more expensive. Plus diesels are built heavier and tend to have a larger oil capacity, hence a longer life. Running biodiesel would be better for them too. Personally I love diesels.
Now on the other hand Propane and Natural Gas are much cleaner running, which will allow your oil to last longer and that help with engine life over a gasoline one. You can get a conversion kit to turn that gasoline one into Propane or Natural gas or all three. I did it with my generac before Y2K http://www.propanecarbs.com/dualfuelconversion.html. Gives you fuel flexibility. But they still will run at 3600 RPM. No matter how you slice it, the engine wears out faster than something running slower. If you just have to have a gas engine or one like at Home Depot, at least get one with a Honda engine. They tend to last longer than a standard Briggs or Tecumseh. Cast Iron cylinders help with engine life too.

[Ryder]

My field of expertise is mainly the Honda, yamaha, and other smaller gas powered generators. I agree that the diesel are probably the most durable if they are well built. Lot's of isolated places in northern canada have a generator out back chugging away. The nice part about propane is that the fuel will store for a long long time. Most gas generators can be converted and with a fairly large propane tank you can forgetabout spoiled gasoline. Your average discount store gas generator does work but don't count on it for long term use. Working in a honda shop I worked on several smaller honda generators that ran every day 12 hours a day for like three years without any major service. I am a fan of the honda and yamaha smaller generators for thier build quality even tho they cost lots more. On the 3600 RPM to give 60 cycles engine speed....higher priced generators now have inverters incorporated into them so that the output is always 60 cycle 120volt no mater the speed of the generator. Nice feature in that small loads let the generator idle down and then when a heavy draw is present the generator speeds up to handle it.
   Reality is that lots of folks have the smaller cheaper gas generators. I personaly have a gas 5500 watt discount one that I plan on using to pump our 100ft deep well for replenishing our water storage. I also have a beat up 500watt portable for lights and battery charging. A nice feature is the built in 12 volt battery charger on some models. Next post I will give a generalized carb cleaning  guide. 90% of the repair work I have done on smaller generators has been because of bad gas. Nowdays gas goes bad really quickly sitting in a small carburator.

[offdalip]

What about when gas, diesel or propane aren't available any more?

A cheap way to make electrical power that anyone can find on any street corner will be
the cars sitting there rusting. I think we could just take the alternator out and just hook it up
to a source of kinetic energy and then presto! instant 12V power as long as the source keeps cranking.
maybe the source can be wind, hydro or mammalian ( like pedaling on a bike )

[AndrewG]

Right you are mister.... At the very least you can charge a 12v battery with it.

[Publius]

What about when gas, diesel or propane aren't available any more?

Instead of storing lots of petroleum diesel, make biodiesel. You could go to Tractor Supply or Orshelin's and get one of those big 1000 gallon stock tanks and go around to restaurants and collect their waste oil and store it in the tank. Make the fuel as needed. I won't go into the collection of WVO, please do the research, because if you just drive up to a grease bin and start pumping, you may end up in jail. Just a thought on the diesel. I'm biased

A cheap way to make electrical power that anyone can find on any street corner will be
the cars sitting there rusting. I think we could just take the alternator out and just hook it up
to a source of kinetic energy and then presto! instant 12V power as long as the source keeps cranking.
maybe the source can be wind, hydro or mammalian ( like pedaling on a bike )

The wind power and hydro have a lot of merit. The bike pedaling would take HUGE amount of effort to charge batteries that you use to run a well pump or something with a large load. As for running a TV and DVD player combo, yes the pedaling idea is good, but not with a car alternator. If you have a small alternator say a 35 amp and it puts out 14 volts, that 490 watts. So if your somewhat discharged battery bank will draw 35 amps, then you wouldn't be able to turn the load enough to do much charging. Now if you had a current regulator on it then you could dial it back to what a human could do. Most newer alternators are 90 amps or so. Some heavy duty one are 120 and higher. The other problem with a car alternator is they are built for higher RPM's than what a human could sustain. A semi truck alternator is built for a lower RPM, and they have higher amperage ratings yet. If you want a pedal powered generator, find a smaller 12VDC motor that you could rig up.  Check this guy out http://www.los-gatos.ca.us/davidbu/pedgen.html

This guy is da bomb. http://www.otherpower.com/otherpowerfront.shtml

Check this out too. http://theepicenter.com/tipoweek.html

[AndrewG]

Could you not use the big pulley, little pulley system to get the rpms up? My power requirements in a situation like we're talking about would be minimal anyway.

[opsec]

I remember an old American Survival Guide article that showed a board that had a car alternator and an engine from a lawnmower mounted on it and connected by a fan belt. It charged up batteries very nicely.

So if I wanted to use such a setup to charge some "AA" NiCad batteries, how would I keep the batteries from getting fried? I know enough to put 8 of them in series to make the battery voltage 12v, but how do I keep the batteries from getting their guts blown out due to current overload?

[AndrewG]

Well, what you just described IS a generator. The best I can give you on the batteries is that you'd have to babysit them. I'm an electrician, not an electronic technician, but think about it like this: Virtually nothing you plug into your lighter is 12v dc. And yet none of those things fry despite the charger having no resistor or anything in it (most times there is a fuse and that's it). I think it may have to do with the regulator wired into the alternator. I'll look into it a bit better for ya.

[opsec]

Thanks. I don't know a lot about electricity. I took electronics in high school but I forgot all that crap.

[Ryder]

As far as charging NiCads, I have used a system where I had a small solar charger (about one foot by one foot) hooked up to the nicad charger. The nicad charger I had used a little transformer that plugged into the wall and had a output of 12 volts. Therefore the solar cell which had a output of 12 to 14 volts under load worked great. One note here is to get a digital volt ohm meter and learn how to do basic readings with it. As far as chargers I know first hand of a guy who used a cevy metro 3 cylinder car with a inverter hooked up to give 110 volts. Powered his cabin for 3 years with this set up. Evidently the car running at a fast idle didn't use very much gas. He just started it up when he needed lights and to watch opra on the small TV.

[Ryder]

OK back to generator repair: First let me say this stuff can be dangerous, I have lit myself on fire from spilled gas several times , shocked myself silly and had to have stitches for cuts self inflicted while taking stuff apart. So reader beware. Follow all of the warnings that came with your generator about fire and fumes and shock.
   The lights go out so you go out to the storage area to start up your generator and it doesn't start. I assume you know nothing about this device except what someone has told you and you are depending on it to light up your world in a time of darkness....First check the oil, some generators have a "low oil shutoff switch" that will automaticaly shut off your generator if it runs low on oil. It might of run fine last time but after sitting around it might not start. What to use for oil? Idealy you have some designated generator oil sitting there but lacking that car oil will work. Supoposedly all modern car oils are compatible with each other so if you have 30weight or 10/40 it should work. find the oil fill hole and top up the oil. The engine will have a dipstick attatched to the fill plug or if it doesn't fill the oil up to the threads in the fill hole. Just filling it with oil will deactivate the low oil shutoff.
  Find the spark plug and unscrew it then plug it back into the spark plug lead and lay it on a metal part of the generator. Make sure no gas is spilled then pull the generator over with the switch turned off several times. If no raw gas spurts out of the spark plug hole then turn on the generator and pull the motor over several times  while watching for a tiny spark to jump across the spark plug electrodes. If it doesn't spark try another spark plug and recheck the on switch.
  check the gas, if it smells really bad and has sat for more than a few months dump it out and refill with some fresh gas. If it is a small generator a quick and dirty way is to tip it upside down in a tub such as a large plastic storage box. this will empty most of the foul gas out of the carb as well. Larger generators might have a drain on the carburator or at least you will be able to see the carb. Having done this put some fresh gas in the tank and pull the starter a bunch of times.....not too scientific but a bunch of times is like 30 to 40 times. Now find the sparkplug and unscrew it to see if it is totaly black and fouled (replace it) or dry as a bone (carb clean time) .
    Still no running generator? I will proceed from simple to complex as some generators have everthing hanging out in the open and others are encased in sound suppression cases. At this point get a pad and pen and a roll of tape you can write on. As you take things apart draw diagrams of where things go and put a piece of tape on the pieces identifying what they hook to and where they go. This way when you put it back together it should work and you won't have caused yourself self inflicted problems.
   Carburators mix gas with air so the engine can burn the mixture to make power. Find the air filter and you will be close to the carburator. The easy part is cleaning the fuel jets in the carburator.....the hard part is getting all the connecting likages and shrouds off the carb so you can work on it.
   Enough for this post....more to come but I need to finish working on a Troy Built Pony rototiller that I was test running by tilling in our rows of unripe green tomatoes. Unbeknownst to me a wire tomato cage was lurking in one bushy plant and the little troy built wrapped it tightly in it's tines before I could "say killer tomatoes from Mars".

[Ryder]

Let's see if the photos come up. I am attempting to show a 600 watt nissan generator that is typical of the smaller "suitcase" type generators. They are covered up to controll sound. You usally have to take most of the outside covering off to work on anything. Save all the screws and make a note of where they go. Then start looking for the carburator which should be connected to the air cleaner.The phgoto with my finger in it has my finger pointing at the carb. I might mention that most smaller generators have some sort of spark arrestor screen in the exhaust. The yamahas are especialy bad about clogging up after being run for a number of hours. Pull the small bolt or screw out of the exhaust tip and sometimes you can pull out this clogged up screen affair. Clean it and reinsert if if you are someplace  with a high fire danger or are runing it in a dry forest enviroment. Otherwise it will run quite nicely with out.

[Ryder]

Here is what the generator looks like.