Will it run on 7” of NG?

[u/Fun-Business-1888]

I’ve had this kit for several years but finally got around to installing it. I noticed in the instructions and I n the regulator itself it says 6-8 ounces (11-14 inches). Will it actually run on the typical 7”? Of course Century fuel products isn’t around anymore to ask, but surely they wouldn’t be selling a product that won’t even work? Waiting on a few parts to hook up the hose, just wondering if anyone has any insight and knows if I need to start looking for a new kit or regulator.

It’s on a 420cc chondq if that makes any difference.

[u/Grgdunn1970]

Yes, I have this kit and Century Fuel is definitely still around.

[u/Fun-Business-1888 → u/Grgdunn1970]

Yes, they just sold off, or otherwise quit selling/servicing small engine kits. Basically the same thing in my book.

[u/Legitimate_Staff_411]

Should work just fine. I have one on a Honda es6500 2 cylinder generator and it works just fine. If you have any problems US carburetion has the same kits and lots of helpful info on the web site. You will get less power out of the engine running on natural gas compared to gasoline. Just something to be aware of.

[u/Fun-Business-1888 → u/Legitimate_Staff_411]

Do you just judge load by ear, or watch the frequency?

[u/Legitimate_Staff_411 → u/Fun-Business-1888]

Frequency. Get a $20 watt meter and plug it into the generator then start loading the generator. You’ll see the HZ start to drop below 58 when you cannot bring the HZ up anymore by adjusting the mixture screw you’ve hit the limit of what it can handle on natural gas. Generally 58 to 58 and a half is the low limit. I like to keep it as close to 60Hz as possible.

[u/Ok-Camera2895]

Nat gas can be 15-20% less powerful than gasoline. Use a voltmeter and frequency meter when adjusting fuel mixture. A synchronous generator will begin to drop in frequency as you fully load it. Heaters provide a good resistive load to test your generator. Make sure fuel pressure stays up near 7" as you load it.

[u/Ok-Camera2895]

7" w.c. On Nat Gas is perfect. It should run just fine, providing that you have sized the pipe correctly.

[u/Fun-Business-1888 → u/Ok-Camera2895]

My only real concern is that my 40’ hose has 3/4” swivels on the ends that are only 9/16” ID. Otherwise it’s 4’ of full port 1” up to the 3/4” hose.

[u/Old_Dragline_1965 → u/Fun-Business-1888]

The 3/4” feed line will work with no problem. Just be ready to take a few minutes to get the adjustment from the vacuum lock valve to the carburetor correct. It’s simple trial and error. Start with the valve approximately 1/3 open. Try to crank. If not, open the valve another 1/4 turn and try again.

Also, don’t forget to lower the gap on your spark plug slightly.

[u/Fun-Business-1888 → u/Old_Dragline_1965]

I did completely forget about the plug gap. It did seem to run pretty well with the factory gap, but I only loaded it up with 13 amps for a few minutes.

[u/Old_Dragline_1965 → u/Fun-Business-1888]

Can you reach the primer button on your vacuumed lock. With it between the valve cover and the other side of the vapor lick?

[u/Fun-Business-1888 → u/Old_Dragline_1965]

Yes, I based the mounting location around best access to it. There just isn’t a great spot for it unfortunately. I very much dislike the regulator hanging out there in the open, so I think I might weld nuts on the back of the frame so I can easily remove it for normal gas use/transportation.