Ltank
I have an older Generac 5242 13kw generator.  It has spark on both cylinders, compression is 200 and almost 210 psi.
  The solenoid resistance is 16.2 ohms,Battery is new 12.8 vdc that drops to 10.8 vdc when cranking. I removed and tested solenoid current at .74 amps at 12vdc tested on a B&K Power Supply. The rubber on plunger is almost perfect barely a mark on sealing surface.  Spring is fine.
  The same cranking voltage is at all points measured and at the battery terminals. Choke works fine when observing starting. 
  So it appears the two stage propane regulator ( has two hoses to motor) is bad. Can I assume it needs replacing? The solenoid sits on top of a small tank. It looks fine didn't look bad. Any insight? Thanks
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78buckshot
The regulator that you are describing is known as the demand regulator, we rarely have issues with them, they are a very simple inlet valve that opens with vacuum created when the engine is cranking or running. The demand regulator does NOT change the pressure of the fuel and has no adjustment. You will find two 1/8 inch pipe plugs with hex sockets, those are pressure test ports, one will be live all the time, the other will show pressure when the solenoid opens. Attach a water manometer or dial gage calibrated for inches of water column, live static LP should be 12.5 - 13.5 inches w.c., running should drop no more than one inch. My guess is you have a fuel problem upstream of the generator.
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Ltank
Thank you 78buckshot.
I will reassemble the electrical wiring and panel the covers over them then get the gas company to test the pressures as mentioned.  It may take a few days for them to get to me and I will let you know what the problem turned out to be.
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Ltank
Ok. The Generator repairman found that the crankcase vent to the air cleaner base was disconnected.  A peice of the plastic base where the hose was connected was broken.  We  epoxies it back in place and it ran. What makes No sense to me is that, he said the motor was sensitive to air fuel ratio. 
    The vent not connected to air filter stops it from starting and running but it will start and run with the air filter cover and filter off?  I couldn't find anything on this in the service manual.  The air filter base only comes with the servo set up for almost 400 bucks.
  Is there something in that circuit that doesn't appear in the manual?
Thanks Guys
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78buckshot
If I were you I would remove the air filter housing and make a more permanent repair with a hose barb or similar to save the money. Did the tech check fuel pressure? Your question about a circuit and reference to the manual is not clear to me, the throttle stepper motor is controlled directly by the main control board and is responsible for holding the engine speed as steady as possible at 3600 RPM with all loads.
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Ltank
I called the Dealer about a fuel issue. The tech arrived and I told him of all the troubleshooting that I had already done. He removed air filter and watched the choke plate operation. Then put his hand underneath the air box between the cylinders and said it was broken. He placed his hand over both intake ports and it attempted to start. He hooked it up and held it in place and it started. But he Never checked the propane pressure. 
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78buckshot
If it now is starting and running dependably then you could leave it alone, LP regulators live in a harsh environment and are subject to loss of accuracy, it's a good idea to check the fuel pressure once in a while.
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Ltank
OK. Thank You for your Help. It's really Appreciated. Thanks
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