I have a Dometic gen that doesn't want to start. I used it last week and it started right up and ran fine. When I went to start it later it wouldn't fire. Seems like it is out of propane. It trys but won't run. One time when it tried it fired and I ran it for about 15 min and shut it off , tried again ---would'nt start I did check the 12 volt cutoff valve and it does open when you try starting. I did make sure the propane tank is full

Is the valve on the tank open? Could be the pressure regulator is bad too. Had one on a new bbq that went bad in just a couple of years.

I took the plug out of the bottom of the regulator,ran a hot wire to the fuel safety selonid and propane came out the the plug hole. When I took the plug from the reg there was a red grease like stuff on it,makes me wonder if reg could be pluged Could you give a squirt of starting fuild in the air cleaner and see if it fires?

Does it have a LOW OIL shut-down?

This sounds exactly like the problem I had with mine. Would run sometimes and then quit, would not re-start, period of run time very variable. I first thought that it was fuel starvation---nope, then I looked at ignition---nope.

What I found was the main power switch on the control panel had gone intermittent. The switch is unprotected from the elements and was corroded inside. (verified by subsequent inspection. This is the bat handle toggle switch. You might try to spray some contact cleaner into the switch and then rapidly move the switch on/off many times. Try to start it and see what happens.

There will be an oily residue coming out of the regulator, normal for propane as there is an oil additive to reduce tank corrosion.

I am on a cruise ship and do not have a good internet service so I can’t locate the write up I did about this problem, it is in the achieves.
HTH

it is on the full mark on the engine oil stick. I took the air cleaner hose off and give it a squirt of starting fluid and it started and ran fine.Shut it off and started again ok. left it sit overnight--wouldn't start.Squirt of starting fluid,started and ran fine again for a hour.shut it off and it acted same way. Just seems not to get fuel to start.

On my previous Barth (90 Breakaway) there was a small cut underneath the clamp on the rubber supply line to the carb .. it would start..stop. Replaced the line and it solved the problem

I have found that when it is cold, my generator will crank for a LONG time before starting. I further found that if I crank for short bursts, it will start much better and faster. I will crank for about 5 seconds, stop and then another 5 seconds. It will usually start on the second or third try.

Some of this is related to the fact that when cold, liquid propane vapor pressure is very low and it will not vaporize in the regulator/vaporizer easily when first starting. By short bursts it lets some of the liquid vaporize a bit in the subsequent tubing and venturi openings so it can fire easier. I also made a mistake of setting the plug gaps too wide, they should be only 0.018" and it will start much better. Once the regulator/vaporizer is heated by the engine coolant, it should start much faster.

You also may have some oil residue in the venturi jets which will reduce the vapor flow a bit during starting. Be careful using any carb cleaner around the regulator/vaporizer. Cleaner will attack the rubber diaphragms. The regulator must be set up using specialized equipment if it is disassembled.

Up north, the big propane generators for industry have elaborate pre-heaters. The colder it gets, the harder propane is to vaporize.

It led me to ask why the use propane for generators if they are hardest to start when you might need it the most. The answer seems pretty obvious once pondered upon, propane is about the only fuel commonly used that will last virtually forever in a stored state.

quote:

Originally posted by Moonbeam-Express:
Up north, the big propane generators for industry have elaborate pre-heaters. The colder it gets, the harder propane is to vaporize.

On the farm in NW Iowa, one winter was so cold that my dad built a pen (with a partial roof) of hay bales around the propane tank and put some of the cattle in it to keep it a little warmer so it would flow. The grass was greener there all summer, too.