Converting Generac Generator from Gasoline to Natural Gas

I purchased the Fuel induction Kit from USCarburetion and installed it on my 33HP Generac engine. The engine will run fine (No sputter and at 3600RPM) using NG. However for it to run, I must engage the choke half way and adjusting the load block for a lean burn. My concern is that the engine appears to be running hotter as I noticed the intake manifold to be quite warm to the touch while using NG as opposed to gasoline. Is this normal, or does the timing or any else need to be adjusted?

On 14 Sep 2006 09:21:48 -0700, "flynet35" wrote:

I purchased the Fuel induction Kit from USCarburetion and installed it on my 33HP Generac engine. The engine will run fine (No sputter and at 3600RPM) using NG. However for it to run, I must engage the choke half way and adjusting the load block for a lean burn. My concern is that the engine appears to be running hotter as I noticed the intake manifold to be quite warm to the touch while using NG as opposed to gasoline. Is this normal, or does the timing or any else need to be adjusted?

Yes, the warm manifold is normal. Liquid gasoline evaporating carries away heat, thus the cooler manifold. NG, since it is a gas has no such refrigeration effects.
However, you still have a problem, one that potentially will cause engine damage. The mixture is obviously too lean. Generally choking isn't required to start or run an NG-fueled engine. It sounds like either US Carb supplied you the wrong kit or more likely, there is something wrong with it or the setup. Did you check all the pressures, both statically and with the engine running? I'm betting that there is inadequate pressure to the engine when it is running. Check the zero pressure regulator to make sure that it starts opening during cranking without the choke.
To gain optimum efficiency and power on NG, the timing should be advanced a bit and optionally, the compression raised. However, it will run just fine with the gasoline setup, albeit with a little less power. Unless you're going to be running it a lot, probably not worth the effort to make any mods. --- John De Armond See my website for my current email address http://www.neon-john.com Cleveland, Occupied TN Don't let your schooling interfere with your education-Mark Twain

"Neon John" wrote in message

On 14 Sep 2006 09:21:48 -0700, "flynet35" wrote:
I purchased the Fuel induction Kit from USCarburetion and installed it on my 33HP Generac engine. The engine will run fine (No sputter and at 3600RPM) using NG. However for it to run, I must engage the choke half way and adjusting the load block for a lean burn. My concern is that the engine appears to be running hotter as I noticed the intake manifold to be quite warm to the touch while using NG as opposed to gasoline. Is this normal, or does the timing or any else need to be adjusted?
Yes, the warm manifold is normal. Liquid gasoline evaporating carries away heat, thus the cooler manifold. NG, since it is a gas has no such refrigeration effects.
However, you still have a problem, one that potentially will cause engine damage. The mixture is obviously too lean. Generally choking isn't required to start or run an NG-fueled engine. It sounds like either US Carb supplied you the wrong kit or more likely, there is something wrong with it or the setup.

Did they maybe send a kit for propane instead of NG? Most gas appliances need minor changes to switch from one gas to the other (orifice sizes).
daestrom

daestrom wrote:

"Neon John" wrote in message On 14 Sep 2006 09:21:48 -0700, "flynet35" wrote:
I purchased the Fuel induction Kit from USCarburetion and installed it on my 33HP Generac engine. The engine will run fine (No sputter and at 3600RPM) using NG. However for it to run, I must engage the choke half way and adjusting the load block for a lean burn. My concern is that the engine appears to be running hotter as I noticed the intake manifold to be quite warm to the touch while using NG as opposed to gasoline. Is this normal, or does the timing or any else need to be adjusted?
Yes, the warm manifold is normal. Liquid gasoline evaporating carries away heat, thus the cooler manifold. NG, since it is a gas has no such refrigeration effects.
However, you still have a problem, one that potentially will cause engine damage. The mixture is obviously too lean. Generally choking isn't required to start or run an NG-fueled engine. It sounds like either US Carb supplied you the wrong kit or more likely, there is something wrong with it or the setup.
Did they maybe send a kit for propane instead of NG? Most gas appliances need minor changes to switch from one gas to the other (orifice sizes).
daestrom

This is actually a tri-fuel system,( Gasoline , NG or Propane). You mentioned that I may damage the engine by it being run too lean on NG. I believe that running NG lean is cooler than runing rich...unlike gasoline. As I mentioned it runs fine with adjusting the choke to about half way. If I vary the choke either more or less the performance decreases or shuts down. My only indication as to why the engine was running hotter was by feeling the temperature of the intake manifold. With that question answered, is it possible that applying some choke is required to get the proper fuel/air mixture on this particular engine. I'm 99.9% sure the installation/setup is correct.