It depends a bit on the model. Locked rotor compressor motor draw is around 50a, which I think is what I think of as the stalled torque draw. I would guess less then that. 
This is the service manual:
To be complete, here is a owners/installation manual.
Use one of these. EasyStart Micro-Air 368 Advanced Soft Start
I should mention you might want to ask someone like a mechanic at a rv center. They probably would know because certainly someone has had the issue of too small of generator or battery system.
I should have thought of that! No wonder we pay you the big bucks 
Warning: many words ahead.
Not an inverter generator, but I finally taped and wired together a charcoal gas generator. The gasifier is a 30 pound, about 30 liters, propane tank. Valve is replaced with 3/4" pipe close nipple, with a pipe cap on the inside as a nozzle, 1/2" hole. There’s another undrilled cap on the outside to close off the air inlet. The tank is used upside down, with a large hole cut in what was the bottom, inside the round base…I left about 3/4 of an inch between the base and the hole, and added a foam neoprene gasket. Cover is a recycled pot cover (we have a great thrift shop in town. Such lids are generally $0.25). It’s held down with a leaf spring bent from steel shipping strap, that hooks into the holes in the base. The filter is a Harbor Freight soup pot, upside down, with a tin can centered inside. The outlet is through a centered hole in both the can and pot. Foam is pressed into the can. The inlet is crudely tangential, at the top of the filter (bottom of the can and pot). Poor man’s cyclone. Maybe just poor cyclone. The pot lid has a foam gasket, and is held on with a spring made from a patio umbrella stay, which I couldn’t find yesterday, so I tied it on with a bike inner tube. Quality and craftsmanship at any cost .
Sump pump hose runs from the gasifier to the filter, and a thrift shop CPAP 3/4" hose from the filter to the engine.
The generator uses a Harbor Freight 212 cc engine, with a pvc tee replacing the air cleaner. 3/4" hose barb for the gas inlet, 3/4" ball valve for mixture control. The engine belt drives a spare Chrysler alternator left over from our 1973 Dodge van (had a 360 V8, but no wood gas). It turns out a scrounged power steering pulley, I think, is a nice press fit on the engine crankshaft. Pulley ratio is 2.5:1. The alternator is old enough that is uses an external regulator. For the trial, I just drove the field rotor with a separate power supply. To try to get a little more power out of the 45 or 50 amp alternator, I hooked up two deep cycle batteries, 24 volts nominal.
For start up and flaring, I used an air mattress inflator that uses four D cells, which fits the air inlet valve nicely. When I used one of these years ago, it seemed like too much flow for a small gasifier, so I replaced one of the batteries with a dummy jumper. It took about a minute to flare, and the engine started easily, since the blower pulls gas all the way to the carb inlet.
Last night I just ran the engine. That was enough fun to start with. This afternoon, I hooked up the batteries and power supply, and ran it under load:
At idle: 25.5 volts X 3 amps = 76 watts
Max. speed, without loading below the governor speed: 33 volts x 20 amps = 660 watts
Maximum power, steady state: 33.volts x 30 amps = 1kw
Maximum power as engine looses speed: 33 volts x ~40 amps = 1.3kw
Total run time was 20-25 minutes. Gasifier was warm to touch, except at the bottom. There’s aluminum anti-sieze between the inner cap/nozzle, so the bottom is pretty hot. No, I haven’t checked the nozzle yet.
For total honesty, subtract 25 watts or less for the field power. It won’t run the house, but it’s a start, and it’s lots of fun to run the machinery on what would have been the burn pile.
That is awesome progress!! You should post pictures! and.or start a thread for it!!
If you want to stack generators forget the inverter genny’s Waste of money, Overprice and when they are done they are junk.
Get the Predator 4375 genny and the EG4 charge Verter. This will cost less money go farther. The 4375 Predatior has 220 volt out so you can take advantage of that. Get a pair chargeverter plus 4375 and combine them on the DC end. If you are wood gassing the engine its so worth building an inverter system. If this is the plan regardless its actually cheaper to build it this way. When 4375 unit dies throw it away and get a new one.
Yeah, there’s something to that. I have 2 inverter-generators now. The first one ran great out of the box. Push button starting for family use, relatively quiet, runs on propane and gasoline. I’m happy with it.
Bought a second one, identical so can be paralleled. Costco had a sale so the price was really good. Oil bottle on the bottom of the box leaked. Oil all over the place including inside where there’s lots of adhesive insulation, thermal and sound, starting to come loose. Bummer. Got a replacement (not without some effort), but it wouldn’t run. Has spark, cranks fine by hand and starter, won’t run on gas or propane. After a lot of reading and learning, and working with the helpful technical service folks, they sent a new carburetor. When I removed the old one, on the side I couldn’t see with it in place, I found a broken wire on the stepper motor for the choke. The new carburetor solved the problem, though it still hunts a little at low load. There’s another stepper motor for the throttle, and no mechanical governor. The inverter module controls the throttle, choke, starter motor, and reads a couple of sensors including a CO detector. It’s all nice, and technically impressive, but without a parts source (which for now seems okay), it would be very tough to home brew repairs.
It’s funny, or maybe not, but I have been thinking of the generator Matt suggested. I like the 212 cc Predator engines, and as Steve has pointed out, you can buy a lot of them for not much money. They were on sale for Christmas for $90 around here. May not be the right shaft for a generator. I don’t know how much electronics these generators have, but the engine probably runs by itself. Maybe it has an electronic voltage regulator for the generator, I don’t know.
I will keep watching for used alternators and old lawn mowers with OHV engines. Those I can probably keep running.
Live and learn, on a good day
The nice thing about the EG4 you dont have to throw it away with the generator when its cycle life is over. An inverter generator when it is done it is done and they are not worth the effort to rebuild them. Just junk it and get a new one. But this way you are not replaceing all of it; only that portion of it.
Yep it is true that the made-for an inverter unit engine side case will be special. The crankshaft stub end special too.
But the same thing for the direct generator head mounted to the engine, synchronous 3000 and 3600 rpm units too.
You would swap out the parts from a stock common 212cc engine to restore as well as possible.
And once the original IC engine in an inverter unit is 2000 hours plus worn out the carburetor, inverter unit, status lights, and controls are then you spare parts source for a low hours, bad-luck unit.
Much interchangeability for a clever handy fellow. Me and any other capable auto tech; small engine guy. Just get a wiring-functional diagram. I have now 3+1+1+1 units now that I could interchange inverter units between each other. Years and years doing similar things. Start young, start old it all begins with a first time make-work swap. You will have successes. You will F’up. Best way to learn. Falling down to learn how to fall. How to get back up.
KentP the units I have bought I specifically got all with manual cable chokes. Many less things to go wrong. And ny I could I get without CO detector systems. Those with . . . I wiring diagram traced and beforehand learned WHEN comes the failure to be able to bypass to keep up and running.
I do the same with the low oil shut down systems. Learn beforehand how to bypass. Then still use them.
I practice unit tipping oil overfilling looking for the oil churning, foaming level. Record a then safe limit on ounces. Then overfill just below that. Buys time once the unit become a worn, oil consumer. Buys service life extension by having cooler running and longer use oil.
DYI home power making and using requires responsibly just like any other power equipment or firearms use.
Those not willing to invest time, reading, research and especially Doer-hours in themselves should just stick with supplied Grid.
Or just buy into a solid state all in a box power station. Now these are being renamed “generator”. A deceiving lie. They are battery banks that must be externally charged up.
Making them direct plug in AC outputs cabable ramps up the internal complexity.
They break; they malfunction, who will be able to repair or restore?
Buy 2-3 Bluetti’s? to have redundancy and backups? You should.
Buy two EG4’s? to have redundancy and backups? You should.
On topic one of the reasons to have stackable or paralleled smaller inverter-genrtors is to aways have some capability.
We each make out choices. Then have to live with those choices.
Regards
Steve Unruh
Ive done it many times. What get for your work isnt worth it. The back cases dont match internally they are diffferent engines. Its by design there is a reson you cant just buy a new engine for the generator otherwise everyone would get them instead of buying a new generator.
Ive two 9500’s and an 8750 new style inverter unit. Come get em get them things out of here. Im done messing with those things. The old school units are more reliable and have more power those things were nothing but problems. The inverters are shot on all three of them. Although the new 459 engines are awesome I will definatly get more those engine, just wont ever get inverter types. I dont have any use for that anyways as my power always goes direct into battery bank.
Hey Matt , how come the inverter units failed ? i would have expected some engine failure due to crappy gas but unless your units are Friday afternoon built units they normaly go on for a fair few years , maybe its just luck as to how well it was put together .
I understand what you mean about running a non inverter type generator into a inverter/charger , but it then will give issues when engine revs are up and down the inverter/charger will be going on off just like your old inverter generators , but this time while its ramping up and down in power your feeding dirty brown un regulated power into the charger giving its more stress , maybe i am wrong .
Dave
Those things are way past thier expected life cycle. Both those 9500 units have been every day since the day they were bought and they were ran 4 to 6 hours per day and everyday. But I was not expecting the inverters to go out just the engines. If you get 3000 hours on one of these engines you have done good. But I think its such a waste as I have to throw the whole thing away. Much cheaper to build modular and those EG4 units will last a lifetime. Those 4375 units are cheap its not worth the effort to fix that old junk when I just buy one fhose for way less money than the cost to fix the existingj worn out units.l
Matt, that is a sweet charger. I just read the spec sheet and it’ll take just about anything from 96-240 volts on the AC side. And I would guess it’s happy with “wild” frequency. So a slower running gasified gennie won’t trip it up.
Given the cost I imagine it’s pretty simple on the inside as well, dominated by some beefy power transistors, capacitors and a smallest inductor(s) they can get away with. If it stopped working… I bet it could be repaired, though I wouldn’t open up something like that without due care. Big caps can pack a punch.
I would think the Predator 4375 would struggle, especially on gasifier fuel, to meet the battery charger’s target output? Does the “ChargeVerter” reduce the charging rate if it detects the generator stalling? That would be huge. Otherwise a 6500 watt predator or even a bit bigger would be in order.
Its fully adjustable thats the beauty of it. Ive dumped dirty power into my EG4 since I got it its fine it dont care. But I dont have the adjustability as the Chargeverter. You can fine tune that thing. The 4375 is good for around 1 kW sustaining especialy if you can ramp the RPMs up a bit. Its about half the 9500 those and the 8750 under constant load can only sustain around 1700 to 2200 watts depending on fuel, the stars alignment and other things LOL .
Its hard to beat one Predator 9500 cost $2400 bucks. For that you can buy two of each of the 4375 and Chargeverter and still come ahead $400 bucks. Then down the line in the future you either fix the 212cc engine or throw it away and buy a new one. Not to mention two is always better than one, you have redundancy. You only have to replace the generator buy the EG4 just once.
The ChargeVerter is specifically designed to handle dirty generator power for RV usage. So its already bullet proof.
I’ll move over here to unburden the Using Charcoal SAFELY thread.
So I think this is an issue. I know propane boils somewhere around -40F (-40 C, too ), but things do change slowly. For a propane tank, the faster you draw off the gas, the lower the temperature of the liquid. The lower the liquid level in the tank, the faster it cools. The smaller the tank, the faster it cools. And the lower the outside temperature, the faster is cools. Eventually, you can’t vaporize the liquid fast enough to keep up, and pressure and flow drop. You can find tables (unverified by me):
that show these relationships. Move from 60 F to 30 F, and your flow drops by 2.5. Go from full tank to 20% and lose another factor of 3. Hook up my generator to the tank that worked fine 2/3 full last summer, when it’s close to freezing today, and, wonder of wonders, it won’t work. It’s right on the edge, so in low idle mode with a light load, all is good. Moving to high idle (normal mode) is enough to stall it. Change to gasoline, and get all the power you want. The moral of the story is: Bigger tank, fuller tank, multiple tanks, or gasoline, when it’s cold outside.
Just so you know, the two vaporization tables don’t agree, rules of thumb for BTUs of propane per generator kilowatt-hour vary a lot, as do BTUs per gallon of gasoline, so this is qualitative not quantitative until you find out who online knows what they’re talking about.