[Probity]

Recently bought a Westinghouse WGen12000DF (dual fuel). I don’t plan on using it with propane, but at the time I couldn’t find a gasoline-only WGen12000 so I spent a little more and got the dual fuel version. I’m now toying with the idea of making it natgas friendly but have run into an oddity regards necessary kit components to do this. Before I trip the trigger buying stuff, I’m looking for any feedback from anybody that has successfully converted either a WGen12000DF or a Duromax XP15000EH (near identical gen sets). Specifically, (1) what natgas inlet pressure at your house do you have, (2) what KN style regulator specifics do you have on your gen set and does it have a manual primer, (3) did you have to modify or install a new “improved flow” 5-way connector between regulator outlet and carburetor. Sorry for amount of detail below but felt it necessary to over-explain vs under.

I was a little surprised when I actually received my 12000DF. As per stock configuration, LP gas from your small propane tank goes first through a Kosan Type 988TW-15 twin stage regulator (6 oz/11” WC outlet setting) and then to the inlet of a Impco/Garretson KN series regulator with a 4 oz/7” WC spring, no primer, tamper resistant, 7/16” orifice. From the outlet of the Garretson regulator, it then goes through what Westinghouse calls a ‘5-way connector’ (a small manifold with 1 large inlet/4 smaller outlets) and then to the carburetor. I don’t care about the Kosan regulator as I don’t plan on using propane, but the Garretson regulator surprised me, I thought it would have been one with a 6 oz/11” WC spring. The p/n of the Garretson regulator (193291) is strange, it’s a new regulator stamped with 4 oz inlet, but not one listed in the current Impco Model KN specs, it corresponds with a superseded Garretson Onan regulator that did (does?) have a 4 ounce/7” WC spring, no primer, and 7/16” orifice. This works to my advantage as I have 4 oz/7” WC inlet at the house for natural gas. Anyway, it is what it is, maybe Westinghouse just grabbed it from the bottom of a parts bin, I don’t know…..

Both the WGen12000DF and Duromax XP1500EH have 713cc v-twin Asian engines, and except for minor differences look like they both come from the same SE Asia factory. Luckily the Westinghouse owner’s manual has some exploded view parts lists (poor as they are). I’ve been unable to find any online Duromax XP15000EH parts list. The carburetor on the 12000DF (Westinghouse ref. 9.22, p/n 322811) is called a ‘double chamber carburetor’. The ‘5-way connector’ is ref. 9.11, p/n 329925. From manual and pic from my genset:

I checked 3 websites (USCarb/Motorsnorkel, Nash Fuel, PNG Technologies) for natgas conversion kits for either a WGen12000DF/XP15000EH.

USCarb – they offer tri-fuel kits for the gasoline-only versions of these Westinghouse/Duromax dual fuels with V-twin engines. MSK3015 - Motorsnorkel by US Carburetion for WGen12000, MSK3019 - MOTOR SNORKEL TRI-FUEL (Natural Gas, Propane, and Gasoline) Conversion Kit - Motorsnorkel by US Carburetion for XP15000. Called ‘double barrel carb’ kits. Include a 6 oz regulator (I shouldn’t need as I already have a 4 oz), load block valve with 2 outlets, small hoses for feeding the carburetor, other hardware. No mention of needing a bigger bore/improved flow 5-way connector.

PNG – they offer natgas conversion kits for both WGen12000DF and XP15000EH (the same kit). Westinghouse Westinghouse Generator Kits (pngtec.com) and Duromax Duromax Generators (pngtec.com). For 4 oz/7” WC natgas line pressure the kit includes a new 4 oz regulator evidently with a manual primer. PNG assumes the gen sets come standard with 6 oz regulators (which is not my case). Other common kit elements include a load block valve (PNG calls it a power elbow) with 1 outlet, fittings, and a user-specified length of ¾” natgas hose with quick-connects. No mention of needing a bigger bore/improved flow 5-way connector.

Nash Fuel – they offer natgas conversion kits for either WGen12000DF/XP15000EH Natural Gas Conversion Kit Westinghouse Duromax XP15000EH Generator Dual Fuel For Sale | NASHFUEL | Propane Fuel Conversion Kit | Nash Fuel. Kit includes a 6 oz (or if you specify 4 oz) regulator (don’t know if it’s with or without primer), load block valve with 1 outlet, small fuel hose, and a new ‘full flow branch valve (what Westinghouse calls the 5-way connector) included to replace existing valve’. I asked Nash Fuel about their “full flow branch valve” – is it actually a different p/n than the Westinghouse one, how much bigger bore is it vs. the Westinghouse one, etc. They didn’t really answer me, just said yes it's a higher flow version than what Westinghouse has. They have none in stock so it’s academic anyway.

With Nash, I can’t figure out why a bigger 5-way connector is needed. If I was going to run just propane, that 5-way connector is supposedly just fine but not fine for natgas? Doesn’t make sense to me.

With PNG, their 4 oz regulator kit has a manual primer, I think my existing 4 oz regulator with no primer should be fine.

With USCarb, their kits seem applicable only for gasoline-only versions and a load block valve with 2 outlets will complicate matter for me.

Anyway, any feedback appreciated.

 

[iowagold]

investigate the 5 way.
it might be the orifice for the system..
hard to tell what is on the inside till you take a look with the hoses removed.
you need maybe 20-30% more flow with NG.
and that is where a screw style load block works well.

so are you wanting tri fuel out of this?
or just gasoline NG?

 

[Probity]

Thanks for reply. I'm only wanting to gasoline-NG the Wgen12000DF, not tri-fuel it. In this post-covid "wait on everything" era, I'm finding too many things basically un-obtainium, like large enough propane tank (120 or 250 gal.) to allow running for consecutive days intermittently (like I had to do with my gasoline-only Champion 6250W/5000W open frame inverter after Ida for 8 days), plus they're pricey too.

Yeah I've procrastinated pulling the '5-way', mainly because I have nothing to compare it to bore/ID wise. But I guess I'll have to do that just to see what the innards look like. I am intrigued by what ajnuzzi says in this thread (2) Question on back up home generator and trifuel conversion | Page 2 | Power Equipment Forum post #21. He doesn't even have a load block at his regulator outlet, he says when the load block/power elbow valve was installed the 12000DF acted a bit starved for fuel but with just a plain adapter fitting Everbilt 1/2 in. Barb x 3/8 in. MIP Brass Adapter Fitting 800199 (homedepot.com) on the regulator outlet it now runs fine. I "think" he mentioned in other threads that he has 50 ft. of 3/4" natgas supply hose going to his WGen12000DF so I'm guessing he was borderline with the 50 ft. of line at the load block. He apparently is using the stock 5-way the gen set came with.

I'm new at this - can you elaborate a little on your comment that I need ~20%-30% more flow with NG? Thanks

 

[sdowney717]

likely needs 10% or higher than that , more flow of ngas to run versus propane.
so yes, the orfice needs to be bigger.
Perhaps it can be driled out.

Also can your gas meter deliver enough gas flow to keep up with demand?
I know gas utility can install a meter that can flow more ngas.

 

[Probity]

likely needs 10% or higher than that , more flow of ngas to run versus propane.
so yes, the orfice needs to be bigger.
Perhaps it can be driled out.

Also can your gas meter deliver enough gas flow to keep up with demand?
I know gas utility can install a meter that can flow more ngas.

Thanks. As noted above I'll have to physically pull and look at that infamous 5-way connector (which is basically just a manifold with 1 size inlet and 4 outlets) to verify what it looks like inside. I'd be very surprised if it's actually got orifices in the flow path, but we'll see. On the gas meter should be fine, it's an AC-250, my portable gen use is for hurricane season when I won't need using my natgas furnaces, so demand other than genset would be conventional water heaters and cooktop.

Just find it odd that 1 company (Nash) says I need a new (bigger?) 5-way manifold, 2 companies (PNG, USCarb) say I don't.

 

[GenKnot]

Just find it odd that 1 company (Nash) says I need a new (bigger?) 5-way manifold, 2 companies (PNG, USCarb) say I don't.

Some of the conversion kits restrict the carb inlet to the point that the gen will no longer run properly on gasoline. The NG adapter must be removed when running gasoline. This could be the reason you are being advised to go with a bigger manifold as you are wanting to maintain the ability to run on gasoline.

 

[sdowney717]

Some of the conversion kits restrict the carb inlet to the point that the gen will no longer run properly on gasoline. The NG adapter must be removed when running gasoline. This could be the reason you are being advised to go with a bigger manifold as you are wanting to maintain the ability to run on gasoline.

Are they doing that to force engine to suck more flow from the Ngas meter?
Or is it a side effect of not having a utility meter that can flow a sufficient amount of required Ngas?
Or something else, like having to do with the gas carb venturi size?

 

[GenKnot]

The propane/NG adapter causes a restriction of air flow in order to create enough vacuum for the demand valve to operate. Unfortunately, it can screw with the A/F ratio when running on gasoline.

It does not necessarily happen with all installations. It seems that if the carb has plenty of capability to run more HP, then it is less likely that the adapter will cause an issue. For example, if the carb is rated for 6-10 HP engines and it is on a 6HP gen, then the adapter is less likely to cause a problem. Conversely, if the 10HP carb is on a 10HP engine then there is less wiggle room for installing anything in front of the carb without causing a problem.

 

[sdowney717]

How do you know which pressure supply you have of NGas, my fuel source is Dominion Power in SEast VA
I have read before that NGas pressure very low.

Example kit, lists 3 different NGas pressures, each kit must have some kind of orfice difference I suppose.
One is 6-8 oz, another 4 oz, another 2 psi

Troybilt 30594 Tri-Fuel (Natural Gas, Propane, and Gasoline) Kit

Troybilt 30594 Tri-Fuel Kit uses an adapter that makes it possible to operate an engine on three different fuels Propane, Natural Gas, and Gasoline.

centuryfuelproducts.com

 

[GenKnot]

How do you know which pressure supply you have of NGas

Calling your supplier may give you that answer, but maybe not.

Measuring the pressure is the most accurate way to find out. You can do it with a manometer. The pressure is usually measured in inches of water column. The typical operating pressure for natural gas appliances is around 7 inches of water column (WC) or, or about 0.25 psi, or about 4 ounces of pressure per square inch.

There are two pressures that you would be interested in knowing. The first is the static pressure supplied by your meter. The second is the pressure at your gen's demand valve with it running full load. The pressure with it running full load will be less than static because of the line drop. The longer the line, and the smaller its size, then greater the line drop.

Manometers can cost anywhere from about $30 to upwards of $300. A DIY manometer can be made for just a few bucks. See a photo in this thread (post #170) for a manometer that reads inches of water column...
(1) Powerhorse Generator with Electric Start — 27,000 Surge Watts, 18,000 Rated Watts | Page 9 | Power Equipment Forum

Just a warning about those...don't have them connected to the gas line when there might be a suction created. For example, if you have it connected to the gas line at the gen and shut off the NG valve with the engine running. The water in the manometer will get sucked into the engine as it is being starved of fuel.

 

[sdowney717]

Calling your supplier may give you that answer, but maybe not.

Measuring the pressure is the most accurate way to find out. You can do it with a manometer. The pressure is usually measured in inches of water column. The typical operating pressure for natural gas appliances is around 7 inches of water column (WC) or, or about 0.25 psi, or about 4 ounces of pressure per square inch.

There are two pressures that you would be interested in knowing. The first is the static pressure supplied by your meter. The second is the pressure at your gen's demand valve with it running full load. The pressure with it running full load will be less than static because of the line drop. The longer the line, and the smaller its size, then greater the line drop.

Manometers can cost anywhere from about $30 to upwards of $300. A DIY manometer can be made for just a few bucks. See a photo in this thread (post #170) for a manometer that reads inches of water column...
(1) Powerhorse Generator with Electric Start — 27,000 Surge Watts, 18,000 Rated Watts | Page 9 | Power Equipment Forum

Just a warning about those...don't have them connected to the gas line when there might be a suction created. For example, if you have it connected to the gas line at the gen and shut off the NG valve with the engine running. The water in the manometer will get sucked into the engine as it is being starved of fuel.

I have never done the conversion due to the extreme rarity of having my power go out. We can go for years with steady power, and when the power is out, its just moments or at most a few hours such as a tree falls taking out the neighborhood.

 

[ajnuzzi]

I have the wgen12000df that I purchased about 3 months ago and converted to natural gas. It was the easiest conversion I've done yet (i've converted a durostar ds12000eh, westinghouse wgen12000df) and it also runs the best on all three fuels. The conversion on this generator is SO SIMPLE. Go on you tube and search up the video PNG made on how to convert it and just watch it carefully. Search "westinghouse wgen12000df natural gas" in you tube and it's the second video that pops up. They actually demonstrate on a Duromax 15000. I did swap the regulator with one that I had from my durostar ds12000eh kit (garretson kn 03-122 6-8oz) because the one that comes with the wgen12000df doesn't have a primer. I've got a 50 ft 3/4" hose that I use to hook mine up with so I really need a primer. I took a hole saw and cut a little hole on the metal plate that you bolt the regulator to so that I could actually have access to the primer button. I have 6-8" wc at my house and am running it off a 50 ft hose right off my meter. Back to the conversion, simply bypass the propane regulator, get a street elbow and go directly in to the regulator and hook your quick connect to that. Then you need one of these from home depot:

Everbilt 1/2 in. Barb x 3/8 in. MIP Brass Adapter Fitting 800199

These hose barbs are made of durable, corrosion resistant and lead-free brass while conforming to NSF 61 and 372 and are registered in Mass. They have several barbs to hold when inserted into tubing. Best for use with plastic, vinyl or rubber tubing. Pair with a hose clamp for a more secure fit.

www.homedepot.com

The fitting that is on the top of the regulator you simply replace it with that fitting from home depot and hook the hose going to the carb right up to it. I originally was using a load block but it wasn't letting enough fuel in. It ran fine but when I hit it with a load I could hear it was bogging down. As soon as I swapped that one fitting out it ran amazing, the thing barely hiccups when I turn my AC on. This worked perfectly and I pulled my plugs after running for two hours and it wasn't too rich or too lean, just right. If you already have your quick connects and 3/4" natural gas hose you literally just need a 3/4" street eblow, nipple, and that fitting from home depot. I did put a ball valve on mine as well but I guess you could skip that if you were trying to do it on the cheap. Feel free to PM me if you have any questions or want pictures of my set up. The best thing about this generator is that after doing the conversion it still runs perfectly on gasoline, and I could run it off propane if I really wanted to with the new regulator, I just just have to get the proper fittings. I could also easily return it to stock too like nothing ever happened.

As far as what your pressure is your meter should say on it what your WC is or you could call your gas company and they should know. Post a couple pics if you can. Now you should be able to do this conversion without swapping the regulator it will just take a minute of the generator cranking before the fuel will reach the carb depending on how long your hose is. I would suggest just using the garrettson regulator that came on the generator before buying another one.

The only "problem" I encountered was how to gap my plugs. Supposed to be .02 for natural gas .03 for gasoline. I do want the ability to run both so I just bought two ngk iridium plugs and gapped at .025.

 

[ajnuzzi]

The propane/NG adapter causes a restriction of air flow in order to create enough vacuum for the demand valve to operate. Unfortunately, it can screw with the A/F ratio when running on gasoline.

It does not necessarily happen with all installations. It seems that if the carb has plenty of capability to run more HP, then it is less likely that the adapter will cause an issue. For example, if the carb is rated for 6-10 HP engines and it is on a 6HP gen, then the adapter is less likely to cause a problem. Conversely, if the 10HP carb is on a 10HP engine then there is less wiggle room for installing anything in front of the carb without causing a problem.

This is absolutely correct for installations with a venturi adapter, where you have to stick something in between the carb and the airbox. Had this problem on my westinghouse wgen9500df and durostar ds12000eh (same motor). Neither would run on gasoline or propane after converting to natural gas. The wgen12000df has a 1/2" hose going to an inlet that is already large enough for natural gas so no modifications are needed that would mess with the integrity of the carb running on gasoline. Only have to swap the fitting on the outlet of the KN regulator and presto, you're running on NG

 

[mmurret]

I have seen (and enjoyed) ajnuzzi’s posts about converting the wgen 12000df to natural gas. I just bought one myself, and wondering if I need to get the load block or just use the nipple adapter you recommend from HD. I was going to order a load block from PNG (only place I found that showed one available), but from your experience it seems like yours ran fine without it. (Plus, the shipping for the load block is more than the load block!). A little concerned about the A/F ratio though. Don't want to burn more NG than necessary, but also don't want to ruin engine either. I have a 1" full port ball valve off my 1 1/4' gas line, and adapt down to to a 15 ft, 3/4" hose with open flow quick connects. My NG pressure is 7" WC, and I noted that the KN regulator on the wgen is rated for that as well (4 oz). I'm getting ready to test it with the nipple. Although the regulator does not have a primer, I'm thinking it should be easy to purge the line and connect the QC coupler and get it to start fairly quickly. I am leaving the original plugs in there for the trial, but have NGK irridiums on order. Any tips/hints/suggestions would be much appreciated. I’m not going to load the gen, jus want to see how/if it will run. Or should I wait until I put in and gap the NKGs?

Also, I would LIKE to be able to start/run my 3 1/2 ton AC on the gen if it can start it. I believe this 16 SEER American Std (Trane) uses a TXV that holds head pressure, and research on soft start kits seems to indicate they don't help much with that. Any experience you wouldn't mind sharing? Thanks for your consideration!

 

[ajnuzzi]

I have seen (and enjoyed) ajnuzzi’s posts about converting the wgen 12000df to natural gas. I just bought one myself, and wondering if I need to get the load block or just use the nipple adapter you recommend from HD. I was going to order a load block from PNG (only place I found that showed one available), but from your experience it seems like yours ran fine without it. (Plus, the shipping for the load block is more than the load block!). A little concerned about the A/F ratio though. Don't want to burn more NG than necessary, but also don't want to ruin engine either. I have a 1" full port ball valve off my 1 1/4' gas line, and adapt down to to a 15 ft, 3/4" hose with open flow quick connects. My NG pressure is 7" WC, and I noted that the KN regulator on the wgen is rated for that as well (4 oz). I'm getting ready to test it with the nipple. Although the regulator does not have a primer, I'm thinking it should be easy to purge the line and connect the QC coupler and get it to start fairly quickly. I am leaving the original plugs in there for the trial, but have NGK irridiums on order. Any tips/hints/suggestions would be much appreciated. I’m not going to load the gen, jus want to see how/if it will run. Or should I wait until I put in and gap the NKGs?

Also, I would LIKE to be able to start/run my 3 1/2 ton AC on the gen if it can start it. I believe this 16 SEER American Std (Trane) uses a TXV that holds head pressure, and research on soft start kits seems to indicate they don't help much with that. Any experience you wouldn't mind sharing? Thanks for your consideration!

As far as running rich I don’t know how to adjust without a load block. I’ve heard of people using a ball valve between the regulator and carb but I don’t think the generators regulator is going to allow too much NG into the carb but I could be wrong. In my case I had to ditch the load block out of necessity. You could try the HD fitting, run for an hour and take a look at your plugs. I can tell my A/f ratio is good based off how the plugs look and how the generator responds audibly to a load. These small simple engines are pretty easy to tell if they’re running right by the sound with/without load and the plugs. Make sure whenever you do get around to testing it you do test with a proper load because if you’re barely getting enough fuel it will idle fine and then bog down under load. I wouldn’t mess with the plugs until your all set and done as far as getting your conversion running right. Otherwise you may be fouling $10 plugs while trying to fine tune your setup.

As far as the AC is concerned mine was JUST BARELY able to start my 3.5 ton Coleman unit without a soft start. I did put a soft start on and it helped a lot although you still hear it struggle a little when it fired up. I would look at the starting amps of the unit before trying to run it and just do some load management- shut off anything with a large draw right before you go to start the ac

 

[mmurret]

As far as running rich I don’t know how to adjust without a load block. I’ve heard of people using a ball valve between the regulator and carb but I don’t think the generators regulator is going to allow too much NG into the carb but I could be wrong. In my case I had to ditch the load block out of necessity. You could try the HD fitting, run for an hour and take a look at your plugs. I can tell my A/f ratio is good based off how the plugs look and how the generator responds audibly to a load. These small simple engines are pretty easy to tell if they’re running right by the sound with/without load and the plugs. Make sure whenever you do get around to testing it you do test with a proper load because if you’re barely getting enough fuel it will idle fine and then bog down under load. I wouldn’t mess with the plugs until your all set and done as far as getting your conversion running right. Otherwise you may be fouling $10 plugs while trying to fine tune your setup.

As far as the AC is concerned mine was JUST BARELY able to start my 3.5 ton Coleman unit without a soft start. I did put a soft start on and it helped a lot although you still hear it struggle a little when it fired up. I would look at the starting amps of the unit before trying to run it and just do some load management- shut off anything with a large draw right before you go to start the ac

Just wanted to add an update to what I found, as well as ask for help with another situation. As far as the load block was concerned, like you said, it did not allow enough flow even wide open. I had to use the adapter fitting. Once I had done that, I could add more load. As far as the A/C issue, the generator was able to start the A/C by itself, but it bogged down greatly before picking up again. The specs on my 3 1/2 ton American Standard A/C show LRA of 109 A and RLA of 16.7A. I only have a 40 yr old Amprobe current meter, so I couldn’t measure inrush current. But using my Fluke 87 meter to measure min/max for 100 msec, the peak was 270 V and the min was 180 when starting. Once it got over the initial inrush (and bog down), the gen ran fine. Pulled about 11 amps running. I bought and installed a Micro Air Easy Start, the first learned start showed 50 A, and after 5 learns the inrush was limited to 30 A. On utility power, using the min/max meter function again, the max was 256 V and the min was 240 V when the A/C kicked in. On the gen and the Easy Start, the max/min was the same! Gen barely noticed it. So the Easy Start lived up to the hype. FYI – found the cheapest price online at a place called WATER YACHT SOLUTIONS (wateryachtsolutions.com) - $325 flat, no tax, no shipping for the ASY-368-X48-Blue.

However, I can’t seem to get the max output I was expecting from the unit (thinking 10/12 kW or 20% reduction from gasoline). Would you mind telling me what you were able to get on yours? When I use my old dryer (18 A) and try to add the broiler on the oven (12 A) it struggles up and down. So I can’t get even 7 kw on natural gas. I can get 20-25 A no problem. I used a Robinair gas pressure meter and took readings at the regulator input and the input to the 15’, ¾” diameter hose, and when struggling, the meter is bouncing between 6.5 and 7.5 WC on both ends. Not sure what this is telling me. I don’t think there is any issue with the meter or piping. The gas meter is rated for 630 C.F.H. The output fittings are 1 ¼” that go into a 1 ½” underground pipe for about 50’, then come out of the ground to a 1 ¼ riser into the house. I had a plumber install a 1” tee w/full port ball valve off the riser, and adapted down to full port ¾” QC fittings. The fact the pressure is just bouncing and not dropping significantly from the 7” WC reading seem to indicate that I don’t have a flow problem Any insight would be appreciated. I could try running on gasoline and see if I can get the full rated 12/15 kw with that – at least tell me the gen is good. But really did not want to put gasoline in it unless I have to. I bought the unit as an “open box” from Westinghouse on ebay. It was supposed to have less than 2 hours on it, and when I received it the hour meter did indeed show 0 hours (unless they reset it). I ran it for the 5 hour break in on propane from a grill tank, but only loaded it with about 3500 watts intermittently. Still using the factory spark plugs. Anyone able to get more out of theirs?

 

[iowagold]

change the plug to ngk iridium.
shoot a video of the bouncing needle.

it could be a bad or wrong demand regulator. that can starve the gen.
what is your cc on the engine? and how many cyl?

if it is 2 cyl take the cc from the charts times 2 for how large of piping.

so on the long run to the gen
what is the pressure?
you might need a bit higher for the piping.

also check the quick disconnects for flow....
a bit of work with a Dremel on the male side can help...
open up the side a bit.

 

[mmurret]

Thanks for the reply, Paul (that was quick!). I have a brief video - see link Bouncing needle This shot was at the output of the 1 ¼” line going to the 1” ball valve. I also used a tee right at the regulator and the reading was the same. When running less than the 7 kW the meter holds steady at 7” WC. Engine is 713cc OHV V-Twin, so about 24 HP. Supposedly the unit was load bank tested (although not on NG) by Westinghouse, so I would assume the regulator is good. It is set for 4 oz (7”WC). Also attached pic. I did not understand your statement “if it is 2 cyl take the cc from the charts times 2 for how large of piping”, but from other online charts it appears 1 ¼” piping is good for a 50’ run for a 24 HP engine. I do have ngk iridium plugs on hand but have not installed them yet per suggestion by ajnuzzi in post #15. Suggestion on Dremeling the QCs sounds plausible, but would do that as last resort if issue is not enough volume. On the other hand, the factory specs on propane are Propane: 10,800 Running Watts | 13,500 Peak Watts, so maybe I am expecting too much on NG?

 

[iowagold]

you need a higher flow rate on NG than on LP.. it is the therms or BTU difference on the two fuels..

unless the NG line is not full flow purged yet??
could have some left over air in the line???

i will have to do some real math...
the numbers look too close to boarder line at first glance...

but i over kill on the flow on the systems here...
i like 1 inch line on gx390 hondas to the shut off just before the hose to the demand regulator...
it took a long time to purge the air out of a short 15 foot run at 1 inch...
let alone at 50 feet...
any 90 deg fittings in that 50 feet???

i would run 2 demand regulators...
one for each cyl...
that would help big time...
and gets the flow rates back to good numbers.
and stop the flutter on the demand regulator diaphragm.

 

[ajnuzzi]

Thanks for the reply, Paul (that was quick!). I have a brief video - see link Bouncing needle This shot was at the output of the 1 ¼” line going to the 1” ball valve. I also used a tee right at the regulator and the reading was the same. When running less than the 7 kW the meter holds steady at 7” WC. Engine is 713cc OHV V-Twin, so about 24 HP. Supposedly the unit was load bank tested (although not on NG) by Westinghouse, so I would assume the regulator is good. It is set for 4 oz (7”WC). Also attached pic. I did not understand your statement “if it is 2 cyl take the cc from the charts times 2 for how large of piping”, but from other online charts it appears 1 ¼” piping is good for a 50’ run for a 24 HP engine. I do have ngk iridium plugs on hand but have not installed them yet per suggestion by ajnuzzi in post #15. Suggestion on Dremeling the QCs sounds plausible, but would do that as last resort if issue is not enough volume. On the other hand, the factory specs on propane are Propane: 10,800 Running Watts | 13,500 Peak Watts, so maybe I am expecting too much on NG?

I have never pushed my gen that much past 7kw. Running my AC was mostly the hardest I went and it ran no problems but I did notice for mine at least it seems to run the same on gasoline or NG. What I mean is the audible “bog” you hear is basically the same between all three fuels with similar loads. I was surprised by that because my last generator CLEARLY struggled more on NG. I guess you could try changing the plugs but unless one of your plugs is fouled I don’t think you’ll see THAT much of a performance difference. I would suggest load testing on gasoline or propane and rule out that it’s running well on other fuels. Maybe someone can chime in who has actually load tested a wgen12000 but from what I understand a lot of these ratings are overestimated - I would not be shocked if 7000 running watts on NG is all we’re gonna get. I’ve heard it’s anywhere from 20-30% loss for switching from gasoline to NG. If it’s closer to 30% and then you have a little bit of loss for the ratings being inflated then you’re right there at 7000. I am curious though I hope someone chimes in that’s actually tested one. For reference my meter is 6-8” wc 275cfh and I’m running a 50ft 3/4” hose.