Generators and Electric Motors
[Home] - [HELP] - [Forums] - [Groups] - [Classified Ads] - [Subscribe] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Vintage Electrical Equipment > Generators & Electric Motors General Discussion
Forgot Password? Join Us!

Notices

Generators & Electric Motors General Discussion Antique Generators and Old Electric Motors: Questions and answers about restoring and showing old power generation systems.

Generators & Electric Motors General Discussion

Generator Not starting on Natural Gas


this thread has 21 replies and has been viewed 15248 times

Reply
 
Thread Tools Display Modes
  #1  
Old 06-17-2013, 10:45:47 PM
sharp sharp is offline
Registered
 
Join Date: Jun 2013
Location: florida, US
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Default Generator Not starting on Natural Gas

I have a gasoline generator converted to run on NG. The problem is that i can't get it started on NG.

The only solution i have found is to start it on Gasoline, then turn the fuel knob off and let it run for 2-3 minutes until the carb is completely dry. At this moment, I try to start it on NG and it starts successfully.

In short, it only starts on NG when the engine is hot. What is wrong here and How can i start on NG without using gasoline every time?

Thanks in advance for help.
Reply With Quote
Sponsored Links
  #2  
Old 06-17-2013, 11:13:23 PM
Billy J Shafer's Avatar
Billy J Shafer Billy J Shafer is offline
Moderator
 
Join Date: Nov 2004
Location: Centerville, Texas
Posts: 18,904
Thanks: 9,981
Thanked 16,729 Times in 7,761 Posts
Default Re: Generator Not starting on Natural Gas

What do you have.
Reply With Quote
  #3  
Old 06-18-2013, 08:10:00 AM
armandh armandh is offline
Sponsor
 
Join Date: Aug 2006
Location: Suburban St. Louis, Missouri
Posts: 3,104
Thanks: 297
Thanked 866 Times in 652 Posts
Default Re: Generator Not starting on Natural Gas

generally cold engines need a slightly rich mixture to start
[chokes are common]
Reply With Quote
  #4  
Old 06-18-2013, 08:46:09 AM
Jim Rankin Jim Rankin is offline
Registered
 
Join Date: Nov 2004
Location: Faunsdale, Alabama USA
Posts: 4,436
Thanks: 71
Thanked 1,185 Times in 967 Posts
Default Re: Generator Not starting on Natural Gas

You can try closing the gap on the sparkplugs as well as richening the fuel-air mixture if possible. It's harder to ignite a too lean mixture.

How does the engine handle a load while burning natural gas?
Reply With Quote
  #5  
Old 06-18-2013, 06:26:10 PM
J.B. Castagnos J.B. Castagnos is offline
Registered
 
Join Date: Nov 2004
Location: South Louisiana USA
Posts: 2,734
Thanks: 930
Thanked 3,587 Times in 1,125 Posts
Default Re: Generator Not starting on Natural Gas

Demand regulators require a negative pressure (vacuum) to allow gas to flow, it may not be opening at cranking speed. Some have a push button or solenoid on the regulator for priming. As mentioned choking may help by creating a vacuum during cranking.
Reply With Quote
  #6  
Old 05-22-2014, 01:28:40 PM
sonice sonice is offline
Registered
 
Join Date: May 2014
Location: Toronto, Ontario, Canada
Posts: 7
Thanks: 3
Thanked 0 Times in 0 Posts
Default Honda EU3000iS generator is not starting on natural gas.

Hello,

Yesterday I spent some time to finish my new Honda EU3000iS generator conversion to natural gas with Impco kit and it did not start - engine sneezes but would not start. My Honda EU3000iS generator is not starting on natural gas.



I learned from this web site
http://www.smokstak.com/forum/showthread.php?t=98125
http://www.smokstak.com/forum/showthread.php?t=98005

that:

Spark plug gap for dry gas engine is usually around .018 as compared to other gasoline engines at .025-.030

I adjusted the spark plug gap to be 2/3 of original size and result is the same. Choking also may help by creating a vacuum during cranking, however it did not help me.

This video below shows that someone is using triple ground electrode spark plug.

https://www.youtube.com/watch?v=_xzWV81FxpQ

I have NGK BP5ES spark plug installed in my HONDA EU3000iS Generator.
This is 14 x 3/4" Reach Threads, 13/16" Socket.

Now I am thinking to use multiground spark plug in my generator, but I am having difficulties to find proper spark plug replacement.

Any help is really appreciated!
Reply With Quote
  #7  
Old 05-22-2014, 01:57:55 PM
Roland Hayes Roland Hayes is offline
Registered
 
Join Date: Oct 2009
Location: Cinderford, Gloucestershire, England, UK
Posts: 1,286
Thanks: 634
Thanked 758 Times in 472 Posts
Default Re: Honda EU3000iS generator is not starting on natural gas.

As a temporary fix you could try a short squirt of aerosol brake cleaner into the intake when attempting the cold start, this will richen up the mixture. I found this to be a good fix on a project back in the day.
Reply With Quote
The Following User Says Thank You to Roland Hayes For This Post:
  #8  
Old 05-22-2014, 08:07:47 PM
b74eqcm b74eqcm is offline
Registered
 
Join Date: Nov 2013
Location: Bethel, Vermont
Posts: 310
Thanks: 174
Thanked 235 Times in 118 Posts
Default Re: Honda EU3000iS generator is not starting on natural gas.

It is also possible that the demand regulator isn't allowing fuel flow. It has to sense enough intake vacuum to allow flow. If the fuel inlet mounts under the gasoline carb, it should work fine.

Are you supplying with the correct gas pressure?

So, if everything else checks out (and don't spend too long on the spark side of things) it's possible the demand regulator needs adjusting. If you take out the brass screw just above the fuel inlet, there is an adjustment screw under. Turn it counter-clockwise (out) a 1/4 turn at a time, and see if it will start. KEEP TRACK of how many times you adjust it (not more than 4). If nothing changes, turn it back to where it started at.
Reply With Quote
The Following User Says Thank You to b74eqcm For This Post:
  #9  
Old 05-22-2014, 08:43:10 PM
sonice sonice is offline
Registered
 
Join Date: May 2014
Location: Toronto, Ontario, Canada
Posts: 7
Thanks: 3
Thanked 0 Times in 0 Posts
Default Re: Honda EU3000iS generator is not starting on natural gas.

Quote:
Originally Posted by Roland Hayes View Post
As a temporary fix you could try a short squirt of aerosol brake cleaner into the intake when attempting the cold start, this will richen up the mixture. I found this to be a good fix on a project back in the day.
Thank you for your prompt reply Roland Hayes,

I am still having difficulties to start my generator.

Do you know how this can be done? Where this so called "intake" is physically located on these pictures below?




I took load block screw completely out and then was slowly moving it in with each cranking attempt. Can I try to adjust the gas flow screw on NG regulator which the manual says that you are never supposed to adjust? Do you know anything about that NG regulator screw functionality?
Reply With Quote
  #10  
Old 05-22-2014, 08:52:38 PM
Thaumaturge Thaumaturge is offline
Subscriber
 
Join Date: Mar 2014
Location: Beryl, Utah USA
Posts: 4,627
Thanks: 3,713
Thanked 4,909 Times in 2,053 Posts
Default Re: Honda EU3000iS generator is not starting on natural gas.

In first of two previous pictures, intake is black plastic box on right. Actually the aircleaner box. Should have air intake slats on it. Could possibly spray starting fluid into those.
Doc
Reply With Quote
The Following User Says Thank You to Thaumaturge For This Post:
  #11  
Old 05-22-2014, 09:29:01 PM
sonice sonice is offline
Registered
 
Join Date: May 2014
Location: Toronto, Ontario, Canada
Posts: 7
Thanks: 3
Thanked 0 Times in 0 Posts
Default Re: Honda EU3000iS generator is not starting on natural gas.

Quote:
Originally Posted by b74eqcm View Post
It is also possible that the demand regulator isn't allowing fuel flow. It has to sense enough intake vacuum to allow flow. If the fuel inlet mounts under the gasoline carb, it should work fine.

Are you supplying with the correct gas pressure?

So, if everything else checks out (and don't spend too long on the spark side of things) it's possible the demand regulator needs adjusting. If you take out the brass screw just above the fuel inlet, there is an adjustment screw under. Turn it counter-clockwise (out) a 1/4 turn at a time, and see if it will start. KEEP TRACK of how many times you adjust it (not more than 4). If nothing changes, turn it back to where it started at.
Thank you b74eqcm,

I did try that brass screw just above the fuel inlet, do you know if generator cold-hot functionality could be affected by that screw?

I was able to make it work, so the generator was working for 30 minutes, I adjusted the load block screw for maximum performance. First I took load block screw completely out and then was slowly moving it in with each cranking attempt.

I connected the load via generator transfer switch I purchased and connected to my electrical panel earlier.

However now after generator was working for 30-40 minutes it became hot and I shut it down and I was trying to re-start it. It would not restart even with any adjustment of the load block screw.

So my question is - this particular functionality problem, when I have found working point of my load block screw when generator was cold and when I try to restart it when it hot after 30 minutes continues operation, it would not start again.

It looks like I need Mechanical Engineering degree to install this IMPCO NATURAL GAS PROPANE KIT to modify so many generator parts and now I need PhD degree in physics to learn how this gas regulator works...
Reply With Quote
  #12  
Old 05-23-2014, 06:59:59 AM
sonice sonice is offline
Registered
 
Join Date: May 2014
Location: Toronto, Ontario, Canada
Posts: 7
Thanks: 3
Thanked 0 Times in 0 Posts
Default Re: Generator Not starting on Natural Gas

In addition to my previous post here is the video I made how I was able to find operating point for load block screw for maximum performance:

http://s1292.photobucket.com/user/so...17f84.mp4.html
<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf" flashvars="file=http%3A%2F%2Fvid1292.photobucket.c om%2Falbums%2Fb564%2Fsoniceone%2FIMG_0236_zpsf2a17 f84.mp4&title=">

However next video shows once generator is hot, it would not start again even load block screw was re-adjusted to full range of motion:

http://s1292.photobucket.com/user/so...0de14.mp4.html
<embed width="600" height="361" type="application/x-shockwave-flash" allowFullscreen="true" allowNetworking="all" wmode="transparent" src="http://static.photobucket.com/player.swf" flashvars="file=http%3A%2F%2Fvid1292.photobucket.c om%2Falbums%2Fb564%2Fsoniceone%2FIMG_0235_zps5df0d e14.mp4&title=">

Any idea how this problem can me fixed? Thank you for all your help!
Reply With Quote
  #13  
Old 05-23-2014, 08:25:15 AM
sonice sonice is offline
Registered
 
Join Date: May 2014
Location: Toronto, Ontario, Canada
Posts: 7
Thanks: 3
Thanked 0 Times in 0 Posts
Default Re: Generator Not starting on Natural Gas

Another question here is how many BTU my 3000 Honda Watt Generator is consuming and if I have hose thick enough for it.

To feed my Honda Generator I use the same Natural Gas Quick Disconnect Hose 3/8" 12 ft. I know that this hose is thick enough to feed my 40 000 BTU grill.

I just found that 1 watt is approximately 3.41214 BTU/h. It means that my Honda Generator consuming 10236.42 BTU/h. Is this correct? This means that Hose 3/8" 12 ft should be fine for my Honda EU3000iS generator as it would consume 4 times less natural gas then my grill.

Am I correct here?

However Honda website would explain that Honda EU3000iS generator can power up 13,500 BTU RV AC units, and more:

http://m.powerequipment.honda.com/ge...odels/eu3000is
Reply With Quote
  #14  
Old 05-23-2014, 08:36:27 AM
Mike Schweikert's Avatar
Mike Schweikert Mike Schweikert is offline
Subscriber
 
Join Date: Nov 2004
Location: Jamison, Pennsylvania, USA
Posts: 767
Thanks: 580
Thanked 536 Times in 199 Posts
Default Re: Generator Not starting on Natural Gas

If that unit has a choke on it, it should be either removed, or wired open.

Any reduction in "suction" will not let the regulator flow gas, as it is a "demand" regulator, meaning that it needs negaive pressure to allow flow.

There may also be a mixture screw in the carb adaptor that requires adjustment. My kit had the load block, and a venturi adjustment on it.

Depends on the kit. I have a 4 cylinder 16hp gen that runs just fine on reg propane hose size (12 feet long) and a 5 gallon can with a low pressure regulator.
__________________
Mike Schweikert
Jamison PA

See my videos at: http://www.youtube.com/user/standardtwin1
Reply With Quote
  #15  
Old 05-23-2014, 10:40:22 AM
sonice sonice is offline
Registered
 
Join Date: May 2014
Location: Toronto, Ontario, Canada
Posts: 7
Thanks: 3
Thanked 0 Times in 0 Posts
Default Re: Generator Not starting on Natural Gas

Quote:
Originally Posted by Mike Schweikert View Post
If that unit has a choke on it, it should be either removed, or wired open.

Any reduction in "suction" will not let the regulator flow gas, as it is a "demand" regulator, meaning that it needs negaive pressure to allow flow.

There may also be a mixture screw in the carb adaptor that requires adjustment. My kit had the load block, and a venturi adjustment on it.

Depends on the kit. I have a 4 cylinder 16hp gen that runs just fine on reg propane hose size (12 feet long) and a 5 gallon can with a low pressure regulator.
Yes, but what is your pipe diameter? You will never get more gas through the 3/4" pipe than will pass thorough the 1/2" pipe.
Reply With Quote
  #16  
Old 05-23-2014, 10:53:09 AM
grif grif is offline
Registered
 
Join Date: Oct 2011
Location: Yakima, Washington
Posts: 1,528
Thanks: 616
Thanked 451 Times in 319 Posts
Default Re: Honda EU3000iS generator is not starting on natural gas.

Quote:
Originally Posted by sonice View Post
It looks like I need Mechanical Engineering degree to install this IMPCO NATURAL GAS PROPANE KIT to modify so many generator parts and now I need PhD degree in physics to learn how this gas regulator works...
If you get two engineers, then you're going to need a good technician to translate to english.

Serious for a bit:
Don't forget, These things have, and do work in the field. It's just a matter of figuring out what ended up different about yours.
Reply With Quote
  #17  
Old 05-23-2014, 11:49:48 AM
dkamp dkamp is offline
eMail NOT Working
 
Join Date: Oct 2007
Location: LeClaire, Iowa, USA
Posts: 1,722
Thanks: 34
Thanked 928 Times in 601 Posts
Default Re: Generator Not starting on Natural Gas

>>I just found that 1 watt is approximately 3.41214 BTU/h. It means that my Honda Generator consuming 10236.42 BTU/h. Is this correct? This means that Hose 3/8" 12 ft should be fine for my Honda EU3000iS generator as it would consume 4 times less natural gas then my grill. Am I correct here?
-------------------------

1 watt of electrical output may be the equivalent of 3.412 BTU, but multiplying that to get an estimate of your fuel demand is incorrect- an internal combustion engine is only about 25% efficient... that is, half the input BTU goes to making waste heat (engine gets hot) and a third of that generates noise, which when equipped with a proper muffler, is converted into heat...

So you can figure that if your gennie is in the average of thermally efficient, you'll be consuming about 10btu of fuel energy for every watt of electrical output. Mebbie better if it's well dialed-in and matched.

None of this stuff requires an engineer, and having a PhD for it would certainly result in no sensible progress. You need a technician, which means you have enough knowledge of the basic operation, and enough knowledge of the real world, and a screwdriver, pliers, and some patience. Usually, these qualities aren't synchrounously extant within academic environs.

My first thought, when you were trying to get it started, was that the natural gas supply may have had pressure, but likely wasn't fully purged.

I don't know what you're connected to for an NG source, but if you're using municipal NG through piping going to a home connection, I would suggest opening the system and letting NG flow for a bit, as you've probably got more atmospheric air in the line than NG. Residual air in the piping from assembly will result in insufficient concentration of NG to actually ignite, and that little engine doesn't draw much, so in the event that you were lucky and had enough fuel in there to initially light up, it probably didn't shut down as a result of hot, so much as it just found an 'air bubble' in the NG supply.

IF it still has gasoline-power capacity, do this:

Put a quarter-tank of gasoline in it, hook it to the NG line. Start the engine, and get it running on gasoline.... then open the NG line.

If there's air in the NG line, the running engine will draw it out as it burns gasoline.

When it gets to NG, the engine's note will change, as the mixture will become fuel-rich. At that point, I'd let it run rich and keep listening... you may hear it change back (air bubble), then again (NG) and again (air bubble) and again (NG). Eventually, it'll settle down and be happy, but rich... this means shut off the gasoline and run NG.

Now... if it doesn't get happy:

One thing you should do, is find your NG regulator and verify proper size and operation. If it's a house NG regulator, it'll be sized in accordance with typical house loads (stoves, furnace, water heater, etc). It must be rated to make the flow for all loads at the same time. Next, the distance in piping from the regulator isn't without resistance... when you apply a flow, the bends in pipe impose a substantial reduction in flow in comparison to a straight length of pipe. Bends in pipe are rated for 'equivalent flow'... i.e., an elbow of a given size may be rated as a 3 foot equivalent, meaning, flow through that elbow is the same as a three-foot piece of straight pipe. It may be that the distance under which you're piped, is resulting in too much restriction for your demand regulator to operate properly.


For the 'magic:

The demand regulator is nothing more than a pressure regulator who's output operates at a pressure BELOW atmopsheric pressure.

Consider a common air regulator on your air compressor... the tank pressure is controlled by an electric switch, and runs it up to oh, let's say around 85psi. You have a regulator and gauge attached, and set the regulator to 32psi, so you can allow a significant other to pump up the tires on a car without having to worry about a drastic over-pressure.

The regulator has a diaphram and a spring. The diaphram is lifted by outlet pressure, and in doing so, pushes against a spring.
The diaphram rests on a needle valve, so when it is lifted, it allows inlet pressure into the outlet side.

Eventually, inlet pressure causes outlet pressure to rise so far that the diaphram closes off the needle valve.

In order to make the regulator maintain 32psi with an 85psi supply, the spring pressure and diaphram force must be equal at 32psi. Good thing that the spring is adjustable... because the diaphram isn't.

Are you with me so far?

What this means, is that with supply pressure being 85psi, and diaphram/spring pressure being set to 32psi, if you vented the outlet to atmosphere, you'd have full outlet flow (through regulator) until such time that atmospheric pressure rises to 32psi. Of course, it won't, so it'll flow 'till compressor fails.

So imagine that you tighten up the spring... that raises the output pressure point to 35psi. Now, do the opposite- LOOSEN the spring. Back it down to 2psi... now you'll have a little flow... not as much, because the diaphram is overcoming the spring and clamping off flow.

Now back the spring down some more. Flow shuts off. That's because, at atmospheric pressure, you've met equillibrium.

Now put your mouth over the outlet, and suck on the pipe. It WILL FLOW AIR. Reason? Because the regulator is trying to maintain atmospheric pressure at the regulator's output, and you're LOWERING the outlet pressure BELOW atmospheric pressure.

A demand regulator, rather than being set for 32psi, or 11psi, or 3psi... is set to flow at somewhere around -1/5th of a PSI. It requires suction in order to flow.

Now for the gory details:

Your input pressure for that regulator needs to be in a certain range. If you put 1000psi on a regulator designed for 85 in, it'll blow up... because it is structurally not capable of handling that pressure. It might handle 200psi, probably leak a bit at 300, and blow clear through at 400, but it'd explode at 1000.

FUEL GAS REGULATORS are UNIQUE. They're SAFETY CRITICAL devices... being such, they must not leak, and when they're being asked to operate in an out-of-range situation (like excessive inlet pressure) they're designed to LOCK OFF, rather than risk losing control of fuel flow. IF you apply too much pressure to a fuel-gas regulator, it will not flow properly, so always verify that you don't have an overpressure situation.

(Side note, for those who eventually read and relate this post to LP... Liquid Propane applications are susceptible to extreme overpressures between regulator stages because propane can be withdrawn from tank or condense to liquid into plumbing between stages, and when temperature rises in those lines, the propane expands considerably, and can cause failures of joints, regulators, and other stuff... bad, bad things happen!)

Another note- Regulators that compare against atmospheric pressure must have a vent which allows atmospheric pressure access to it's internals. If the vent is plugged or restricted, it will NOT work properly.

Another, another note: Regulators that contain fuel-gas usually have, in conjuction to lock-off design, also have an extreme overpressure feature that, when subjected to out-of-range input pressures (like liquid propane's hydraulic expansion), will protect themselves by relieving inlet pressure through the vent.

I'm certain you're not having this problem with your demand reg, but wasps love to build nests in places like gaseous fuel regulators... so check your house regulators.



On a fuel-gas system, readings are usually done in PSI for the distribution legs (high pressure municipal gas mains), and the first-stage regulator (at your house) knocks it down to a lower level. Typically, when it comes through the wall of the house, the last regulator before the foundation will have it at a pressure of around 11 "inches of water column", or it's equivalent of something like 5-7 ounce-inches of force. What this amounts to... is very little pressure.

From there, it goes to your demand regulator... which expects around 11" w.c., and 'demand regulates' it at whatever a respectable vacuum draw for your engine's fuel venturi will DEMAND.

One can measure pressures using a manometer made from clear tubing. Dip a 3-foot piece of clear tubing in water, so it's half full, lift the ends up. Mark the level of one side of the tube, and blow into the other hard enough to raise the water up 11 inches... and the pressure you're applying, is eleven inches of water column.

One can use a homemade water-column to measure and set a demand regulator, using a very, very crude technique. Put the fuel supply hose in a bucket of water 14" deep. When you plunge it to the bottom, if it bubbles, you have MORE than 14" of water-column pressure. Raise it to 11... if it starts bubbling at 11", you have 11" wc pressure. At 9", it should bubble nicely.

One can make a crude, but extremely effective demand regulator using a bucket of water, a hose, and some way to seal off and draw vacuum on the top of the bucket.

(by the way... If one were to make a comparable 'demand regulator' for a liquid fuel application, it'd consist of a float and a needle valve)

So what this all boils down to (oooh... pun!), is that either you have adequate fuel flow, or you don't. You may or may not have proper pressures for everything to function. You MAY have proper pressures, but what you're getting through the pipe at this time, may not be combustible.

There'll be a quiz on Friday. Uh.. wait... today IS Friday...

Class DISMISSED!

Last edited by dkamp; 05-23-2014 at 12:07:39 PM. Reason: grypotrafical errerr.
Reply With Quote
  #18  
Old 05-23-2014, 12:00:50 PM
len k len k is offline
Subscriber
 
Join Date: Jun 2012
Location: Manchester, New Hampshire
Posts: 19,122
Thanks: 659
Thanked 7,347 Times in 5,224 Posts
Default Re: Generator Not starting on Natural Gas

Quote:
Originally Posted by sonice View Post
I just found that 1 watt is approximately 3.41214 BTU/h. It means that my Honda Generator consuming 10236.42 BTU/h. Is this correct?
No , as a rough estimate gen is only < ~25% efficient at turning fuel energy into electrical energy. So you need roughly at least 40K BTU/hr flow rate , that's on par with a propane BBQ grill. But nat gas has a little less energy per unit volume (maybe 25% less), so a nat gas pipe likely should be a little bigger in ID, because you'll have to flow more of it. There are standard tables for required pipe size for given flow rates and lengths, obeying them prevents troublesome/excessive pressure drops to demand reg. Post an email adress and someone will send one. Others here are more familiar with them than I am.

Dkamp... just saw we both posted at same time.

If your using a long leg of nat gas pipe in your house that has been shut off for 6-12 months, or a newly installed pipe, you WILL need to purge it, it's common practice. But since you ran gen for 30-40 minutes on nat gas, it's likely now purged.

On center back of your demand regulator there should a prime button that you push for ~1 sec to richen the mix for starting.

Not sure if it's your problem, but when you run on nat gas, spark is usually advanced alot more. Because it burns more slowly than gasoline, ~25degs of advance vs ~10. And reduce the spark gap, (nat gas has a higher ignition temp than gasoline). Don't think your special 3 electrode spark plugs are going to be better unless you have a high power spark coil to drive them, so more than 1 arcs. Check presure at inlet of demand reg 1-st, not sure but I thought nat gas was 5-6 inches of water pressure and propane was 11. (No translator needed. )

Last edited by len k; 05-23-2014 at 03:17:23 PM. Reason: add more info
Reply With Quote
  #19  
Old 05-23-2014, 06:43:12 PM
dkamp dkamp is offline
eMail NOT Working
 
Join Date: Oct 2007
Location: LeClaire, Iowa, USA
Posts: 1,722
Thanks: 34
Thanked 928 Times in 601 Posts
Default Re: Generator Not starting on Natural Gas

NG is typically expressed in ounce-inches... 6 oz-in comes out to just under 11" w.c... hence, the difference.

The demand regulator has one basic adjustment... it's a 'bias' or sensitivity adjustment. It's one of those things they say 'don't touch', because if you fiddle with it, you'll change not only the regulating pressure point (engine vacuum required to open), it also changes how well the regulator 'locks off' fuel flow when the engine is stopped.

See, when the engine cranks, if it doesn't exhibit sufficent draw, it won't pull fuel. Something as simple as a plugged-up exhaust pipe will prevent sufficient cranking vacuum. I'll leave it at that, because it's your starting point.

The other adjustment, is the 'load control' screw... it's essentially an orifice that limits fuel flow... set it according to full-load mixture requirements.

One other note... I see that you used teflon tape on the threads. Two known issues with teflon tape, are that it's not uncommon for people to use the 'wrong flavor' of tape... there's tape specifically for fuel-gas use, and tape for sealing air and water plumbing. Can't mix/match 'em- they need to be appropriate to the task, lest you end up with bad situations... AND...

Sensitive control valving really DOES NOT like teflon tape in it's realm. Little bits of the stuff will come off and wind up plugging up valves and orfices. You may have suffered such a fate... resulting in sluggish operation and overheat.
Reply With Quote
The Following User Says Thank You to dkamp For This Post:
  #20  
Old 05-23-2014, 07:36:15 PM
len k len k is offline
Subscriber
 
Join Date: Jun 2012
Location: Manchester, New Hampshire
Posts: 19,122
Thanks: 659
Thanked 7,347 Times in 5,224 Posts
Default Re: Generator Not starting on Natural Gas

Presure, in different units of mesurement.

11 inches of water = 0.397 psi (Pounds/square inch) = 6.36 oz/ square inch
Reply With Quote
Reply

Bookmarks


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
portable generator convert to natural gas JeffK Generac Generators (SEARS, etc.) 12 12-03-2016 11:49:49 PM
Wisconsin THD natural gas generator MXB Generators & Electric Motors General Discussion 9 04-24-2013 10:36:53 PM
I want to run my Natural Gas Generator off of Propane. What do I need to know? Nyatha Kohler Generators 6 04-08-2012 11:24:39 AM
natural gas generator bentley Generators & Electric Motors General Discussion 4 06-22-2004 04:31:41 AM
FS 50KW natural gas powered generator Dave Wright Generators & Electric Motors General Discussion 0 01-30-2003 01:26:22 AM


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 08:55:08 PM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2019 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277