I can't speak for everywhere, but up here in Alaska #1 diesel is JetA50
Grade, at the Distributer and I believe that ALL our fuel is Low-Sulfur
with a Lubricant Additive Package added to fuels used in Injector and
Turbine based ICE's. Since I burn only #1 in my Gensets, so that I only
have to have one grade of fuel here at the cabin, which has a Open Pot
Diesel Burning Cookstove, and is my Primary Heat, and Hot Water source.
The fuel I get has the Lubricant Additive Package added, and the same
tanker barge delivers to the AirStrip in the next town over, from the
same tank, on the same trip.
Bruce in alaska
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I have known people who do the same thing, only they started to have to much
injector pump problems. They started adding 1 quart of 30 weight oil to a 25
gallon tank to put the sulpher the older diesel engines required. That was
quite a few years back they were doing this.
A couple of years ago I was looking for a replacement generator engine. The
Honda GX270 was going for just under $700. A comparable Chinese engine was
selling for around $250, but I couldn't find any with a tapered shaft. It
sure seems like there is a market for a replacment generator engine that a
"standard" generator head would bolt right onto. Many times I've considered
replacing my "use only as a last resort" Tecumseh-powered generator with an
OHV engine but since then I've actually managed to get it running well. I
replaced the fixed idle mixture jet with an adjustable screw and
disconnected the crankcase breather and attached a primer tube and now it
starts with one pull! It's like a miracle. I've actually been using it on
a daily basis lately to run my well pump. I must give them credit for one
thing though: on a really cold day it would really warm you up yanking on
that rope trying to get it to start. I'd sometimes be so hot I'd have to
take my shirt off when it was 20 degrees.
Often time you have to special order an engine with the taper shaft because
they are a specialty item that doesn't move very fast. There are so new
engines on Ebay under generator parts. I have seen several 10 HP Tecumseh
engines there. They also have a 6 HP OHV that I have been wanting to get
before they are gone forever.
I have one of the Harbor Freight 6.5 HP OHV engines that are currently
selling for $110. I got mine for $99 about a year ago. It's a straight
3/4" keyed shaft so it's good for belt-drive etc. The only problem I've had
is they have some kind of fuel vapor device on it that gets clogged and has
to be blown out or the engine will die from no air. I rigged mine with an
external gas tank so no more problem. In any case I think it's a good
engine and would rather have it than my Honda GC135.
OLD? They made them for a long time. Don't know when they stopped. If age
bothers you, find a newer one, but some of the older wones were the best
Sorry, I don't know anything about your neighbor so I can't argue about
that, but I can tell you about my Onan because I have known it since it was
new. It was perhaps 30 years old when I bought it from my employer. Except
for sparkplugs and batteries, it was all-orignal. Nothing had ever broken!
To be honest, after I bought it, I did have some problems with points.
Perhaps the problem was the mechanic (me). Anyhow, I solved that issue with
an electronic ignition conversion.
There is a germ of truth here. We are talking about something that was
designed when gas cost 50 cents a gallon! There are certainly more
efficient generators around, but they are not cheap and you are unlikely to
find them at Home Depot. Fuel cost is important (OK, damn important), but
it is not the only cost of running a generator..
Running at 1800 RPM (vs 3600 RPM) drastically lowers the pumping loss of the
engione (increasing efficiency), greatly decreases noise, and reduces wear.
"Better" (commercial quality) engines are expensive and are not found on
consumer-grade generators. I expect my Onan to outlast me. I can't say that
about any other small engine I own.
No, you can't throttle a conventional generator down to lower speed if you
want 60 HZ power. Running at 1800 RPM (vs 3600 RPM) drastically lowers the
pumping loss of the engione (increasing efficiency), greatly decreases
noise, and reduces wear. Yes, you could design your own generator with a
throttled-down 3600 RPM engine and a belt ratio to get the proper frequency,
but you would no longer get rated power from the engine.
Finally, these (Onan) generators are made for motorhome use. They must fit
into a minimum space, must have reliablility comparable with the vehicle's
engine, and must run with minimum noise and vibration. My neighbors don't
even know that I have a generator because they can't hear it!
I don't mind old stuff, I have lots of it. In this case though, the
older versions are better in some ways, but not in the most important
ways IMO. It's much the same with my old tractors. They're good in
that they're relatively easy and cheap to repair, but in terms of
efficiency and productivity, their designs were outclassed decades
Let's make a fair assumption that the flat-head penalty is 20%. For
every gallon of fuel burned per day, by using an overhead valve engine
one could save enough in a single year to buy an entire spare 13 hp
But they're *not* as efficient as OHV competitors. If they were, then
Onan wouldn't have switched to OHV.
Somebody wrote that these engines can make 10,000 hours before the
first rebuild. But didn't Ulysses get more than that out of an EU
engine? Yes, the Onan can be rebuilt over and over, but what's the
point if that costs more in the end?
I didn't mean commercial quality, only anything with a cast iron bore
and a decent oil filter.
One can say the same about an old power drill for example. But it's
still more practical and cost-effective for most to buy a modern
True, but most of the DIYers here seem to be using belt-driven
arrangements. My own is overpowered (larger displacement considering
the output, just like the old Onans), and is throttled down to about
Aren't the new Onan RV generators 3600 RPM? Then it seems that lower
RPM isn't the single secret to low noise. Anyway, if we're trading
anecdotes, my neighbor with the old Onans was impressed with the quiet
of my plain-jane Kohler in a simple enclosure. :-)
This is from a CL ad:
Model 6.5 nh-3cr. 6500 watts, 120-240 volts. 54.2-27.1 amps. Phase 1. Starts
dependably. Hear it run. Like new! Came out of wrecked motor home. New
plugs, wires, points, condensor, oil and filter, 30wt. non-detergent. New
fuel pump and air cleaner. Dimensions are 23" in Heighth, 32" in width", 20"
depth. Mounting plate is 19x19
All of this makes me wonder about maintenance. There seems to be a lot of
stuff there that I currently don't have to deal with. How often does the
oil need to be changed on these generators? Does the oil filter reduce the
frequency of oil changes or just improve the lubrication? Does the flywheel
need to be removed to adjust the points or are they easy to get to?
Most Onans that I have seen have the points box on the top of the engine.
Still not always convenient, but at least you don't need to dismantle the
engine. The manual for my CCK (no oil filter) specifies 100 hours. That
might sound like a lot, but it would be the same as several thousand miles
in an auto engine.
Actually, it doesn't really sound like a lot to me. I am guilty of pushing
the limits on some cheap engines as far as oil changes go. I used the
change the oil on my Chinese 2000 watt genny every 50 hours, as recommended.
It has about 3000 hours on it now and I've been changing the oil about every
100 hours (or slightly more) for about the last 1000 hours. At 100 hours
the oil is still transparent and not very dark. Looking at the oil may not
be the best way to determine when to change the oil but it seems to be
working for me. OTOH on a Briggs I might change the oil after only 25 hours
because it'll look black and yucky by then.
Maintainance is the key to longevity on ANY Mechanical Device. Having a
Pressure Lubeoil and Filter System increases the Oil change Period form
50-100 Hours, to 200 Hours, or once a Year, which ever comes first, on
the Onan Engines, and MOST other 4 Cycle Gasoline Fueled ICE's.
Converting to Dry Gas Fuel can increase that to maybe 300 Hours, BUT,
remember that LubeOil, is the cheapest Insurance MOney can Buy....
Very Few of the classic Opposed Twin Onans are Magneto Ignition, so in
most cases, the Points are located on the top of the Engine near the
Carb. This class of Onan Gensets are KNOWN for their reliability, and
long Lifetimes, (10K Operational Hours) IF the OEM Periodic Maintainance
is done. The problems come when some owners just think they can store
them away, for years, sometimes, and then drag them out, blow the dust
off, and expect them to start and run, 24/7/Days or Weeks with no
issues.... That expectation, is just plain stupid, for ANY ICE, not
just Onans. If you can't, or don't, do the Periodic Maintainance, don't
expect to have power, when the Grid goes down..... and that classes you
as a "FlatLander".... "City Boy" for you Red Neck Types....
Bruce in alaska
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I am reTired, and the only reason I have, what I have, is that I got an
education, worked HARD for 40 Years, saved my money, invested wisely,
and knew when to get out. Now, I have skills that are sale-able even in
reTirement, and I live where, and how, I want to. NO Trust Fund, and
never had a Six Figure Income in any ONE Year, in my life. I always
worked for wages, even when I was a FED, and now folks pay me for those
skills, I have acquired over a lifetime, as a Consultant, when I choose
to actually accept a Job.
Bruce in alaska
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