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DuroMax XP12000EH Won’t Start on Gas OR Propane… Here’s What Was Really Wrong

TTMechanics

5,082 views

Parts and tools used in this video:
• DuroMax Part # 50280023 Second Stage Propane Regulator
• 8mm & 10mm Sockets / Wrench
• Wobbly Extensions
• Starting Fluid

DuroMax XP12000EH Generator Won't Start on Gas or Propane. Customer reports that generator ran for about 15 minutes then died. In this diagnostic session, we tackle a DuroMax XP12000EH dual-fuel generator that refuses to run on either gasoline or propane after suddenly dying during use. The diagnostic journey starts with checking the oil level, inspecting the gas tank, and utilizing a quick spray of starting fluid to isolate fuel, spark, and timing issues.

After discovering a disconnected spark plug wire and a loose plug, we shift our focus to the fuel systems, uncovering a damaged propane regulator that requires a full component replacement. After swapping out the faulty propane regulator, we purge the residual gasoline from the carburetor float bowl, dial in the engine frequency, and remove the leftover red shipping brackets that violate warranty terms. The final solution gets this heavy-duty dual-fuel unit running smoothly on propane and ready to head back to the customer.

WHAT WE COVER IN THIS VIDEO:

0:00 Initial Diagnosis & Oil Check
2:28 Gas Condition Inspection & Starting Fluid Test
4:39 Spark Plug Discovery & Gap Check
9:08 Running on Gasoline & Voltage Verification
13:02 Propane Regulator Inspection & Removal
22:02 Installing the New Propane Regulator
39:08 Purging Gas and Starting on Propane
41:27 Frequency Adjustment & Governor Overview
45:28 Removing Shipping Brackets & Final Shop Tips

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#DuroMax #GeneratorRepair #SmallEngineRepair #DualFuelGenerator

20 Comments

@Rein_Ciarfella 7 months ago

Since my previous comment about tighter camera shots you both have really improved remarkably! Thank you so much for that effort - the difference is apparent! 🙏👍

@Rein_Ciarfella 7 months ago

After finding the issue I really appreciate that you kept going and gave us a lot of information about propane systems. I learned a lot from this video, Matt, so thanks!

@kennethnegaard7599 5 months ago

Great Video. Learned a lot. Thank you.

@pit4955 7 months ago

6” water column 1/4 pound, great vid thx for sharing 👍

@nickkucherov9760 1 month ago

Outstanding tutorial. Thanks

@billsimpson604 7 months ago

All the new propane tanks have a safety system in them to prevent overfilling, and to stop dangerous leaks should a hose get cut. It sounds crazy, but if you open the valve on the tank too fast the safety valve in the tank will shut off the flow of propane gas, 'thinking' that there is a big leak. If that happens, you need to shut off the valve, disconnect the hose to release the pressure, then reattach the hose and open the valve slowly. I had no idea that could happen until I read about it on the internet. Decades ago, you could open the valve on a propane tank, and gas or liquid propane would shoot out, not anymore. I used to like to watch the liquid propane boil off outside. That is what will happen to your blood if you got a big leak in your space suit on the Moon or Mars.
There are plenty of videos on how to test and repair the generators. But they are usually pretty durable, depending on hours of use and load on them when they are running. Keep them as cool as you can.
Propane produces less power than gasoline. But propane burns cleaner than gasoline. I always use propane since it can be stored forever.

@patricksquires77 2 months ago

💯

Too many times that shipping bracket is still on a duromax.

The second thing people don’t know with these is you should change the oil every whole day of use - this is not a model to just change once a year but have run for days at a time.

@charlescoker7752 3 weeks ago

I would spray some fogging oil in the cylinder. Pull the cord a few times to get the cylinder wall covered . Then start it up if it has set for a while. Our local fire department starts ,and runs their generator every morning. Like clock work. To make sure it will run if needed for that day.

@JamesGowen-z6d 7 months ago

I have an xp 13000 hxt tri fuel, had it running on gas, stopped it to hook up ng, would start but would die swap back to gas and would do the same thing, ask duromax for help they sent me a check list, I finally found a plug in the wiring loom that had come unplugged.

@Rein_Ciarfella 7 months ago

I do the same when first inspecting a machine - check oil level and condition, check gas level and condition and condition of tank. I sometimes also pull the spark plug, checking condition, tightness and gap. I often check compression while I have the plug out. These together give me a lot of information about the engine and owner.
After this video I’m altering my inspection algorithm to always perform the spark plug and compression measurement as well! It takes hardly any time and rules out a lot.

I really like to try and guess what the issue is before watching the rest of a video after hearing the customer complaint. My main thought on this one was what things do both fuel systems have in common that would cause this issue? I settled on ignition as the most likely, followed by electrical, such as a ground or kill switch issue. I was totally surprised to see the actual cause was the spark plug boot not being connected! So simple but unsuspected!😂

@Rein_Ciarfella 7 months ago

08:15 I’ve always hit spark plugs and lug nuts with a little oil of any kind. Been doing this since the late 1950’s. Never an issue.

@MannyFontes1968 2 months ago

You can build a shed around as long as you ventilate it correctly, meaning adding an exhaust fan that creates cross ventilation by sucking in fresh air and moving out the exhaust air.

@johnhershey4010 7 months ago

You can still fix the generator even if one side is not running

@Rein_Ciarfella 7 months ago

I thought about this a lot and I wonder whether you could have replaced the second stage regulator much more quickly by blocking the axle up and removing the wheel to access the connection as well as the back bolt on the bracket holding the regulator. The number of steps to remove the air filter housing compared to the wheel is significant. If the axle is blocked up high enough the vicegrips could be applied from below and the adjustable from the side.

@dlawson8993 1 month ago

Do you thank the duramax inverter generator are any better than the other brands seeing it has a fully copper wond engine?

@socrates2706 7 months ago

Thread sealant on the regulator connection? Test the regulator before reattaching?

@tomkowalski6121 3 days ago

Can someone help me with telling me where can I buy this regulator please? I look all over the internet and I could not find any vendor...

@spockmcoyissmart961 2 months ago

Typically n gas/Propane uses flared fittings..

@charlescoker7752 3 weeks ago

Bought a Coleman 4,000 watt generator in 1999. Had no problems with it until this year 2026. It started back firing. Run about 60 seconds. Then stop. What do you think is making it backfire?