Predator generator leaking fuel

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  #1  
Old 09-14-15, 12:37 PM
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Predator generator leaking fuel

Don't hate my choice of generator.

I have a Harbor Freight/Predator 7000/8750 watt portable generator. I run stabilized fuel in it, exercise it once a month, and swap the fuel twice a year. I was doing my fuel swap today, siphoned out most of it, closed up the gas tank, went to start it to exercise it with the remaining fuel, and had issues.

The pull on the recoil start was a bit stiff on the first pull. I let it recoil, gave it another pull, and it didn't want to budge - and I didn't want to force it. I then noticed that there was a dribble of fuel coming from an area by the carb. I have attached pictures and circled the area. When I turned off the fuel shut-off, the fuel leak stopped. Open the fuel shut-off, it leaked again.

Thinking that the carb could have been gummed up somehow, I opened the drain plug on the carb. Fuel drained out. I also tapped on it to potentially dislodge anything stuck. I opened the fuel shut-off valve again, and there was no leak.

Oil level is also good, and had fresh 10W30 synthetic about 3 months ago.

I tried to start it again, and it started. I ran it for about 15 seconds and then shut it off to talk to you all.

What is that little port it was leaking out of, and what do you think happened?

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  #2  
Old 09-14-15, 03:46 PM
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You might have a needle valve/float problem in the carburetor. It's probably not stopping the flow of fuel into the carburetor and causing it to over flow and flood the engine. I'm guessing the first time you tried starting the engine there was more time between when you opened the fuel shutoff which allowed it to flood. Then you turned off the fuel shutoff and drained the carburetor's bowl and might have gotten it started before it over flowed again.

With a full fuel tank and the engine off open the fuel shut off valve. If after a while you see fuel dribbling from the carburetor or if you notice the cylinder filling with fuel or the oil level magically rising then you probably need to remove the carburetor's bowl and see what's going on.

---
Do you use the generator other than just exercising? I'm wondering why you store it with fuel in it?
 
  #3  
Old 09-14-15, 05:37 PM
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Did you start it again and let it run for 5 minutes or so ?

Was the carb leaking again after you ran it ?
 
  #4  
Old 09-14-15, 06:37 PM
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I only ran it for that 15 seconds or so. It seemed to run fine and was not leaking fuel during or after. After that, following Pilot Dane's advice, I went out and turned the valve on. No leaks for about 5 minutes. Tried giving the recoil a tug (not to start, just to feel for resistance), and it turned easily once, then gave a lot of resistance - more than normal. Concerned that I might be hydrolocking it, but light was fading and it's not mission critical right now. I'll go out and check it in the morning, maybe pop the spark plug out, and try it from there.

PilotDane, I was actually thinking about putting it into a dry storage. It had basically been a standby generator, as every time the wind blew, we lost power. The power company recently did some line work that has much improved service, so it looks like the need is much less now.
 
  #5  
Old 09-15-15, 05:23 AM
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Stabil and other treatments help preserve gasoline but they only slow down the souring process. The gas will still go bad and the methanol in the fuel will still absorb moisture, and the finer hydrocarbons will evaporate off making the fuel less "explosive" which can made the engine harder to start.

I go to the local airport and by a small amount of 100LL (100 low lead) aviation gasoline. It is highly refined, does not produce varnish and is formulated for long term storage and stability under a wide variety of conditions. It also contains no methanol so it will not absorb moisture from the air.

Drain your generators fuel tank. Drain the carburetor's bowl. Then put the avgas in the tank and start the generator and let it run for a while to make sure the avgas has washed all the auto gas out of the carburetor. You can either leave just a small bit of avgas in the tank or completely fill it to minimize condensation inside the tank. With avgas in the tank you can use the generator periodically without worrying so much about ruining your long term storage prep.

When the power goes out just refill with regular gas and use the generator normally. Just remember to go through the long term storage procedure when the lights come back on.

---
Never put avgas in any automobile or electronically fuel injected vehicle. Avgas contain lead which will kill oxygen sensors and catalytic converters. Avgas is also great for de-greasing and washing parts as it does not absorb into your skin leaving you smelling like gasoline for hours. It evaporates away quickly but don't lick your fingers. That white chalky residue is lead.
 
  #6  
Old 09-15-15, 08:22 AM
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Super, have you considered a conversion to gaseous fuel? If you have natural gas or a large bulk tank of propane this is the BEST fuel for your generator. It eliminates all the problems of gasoline and increases the engine life considerably along with reducing the frequency of oil changes.

I use natural gas on my generator and I would NEVER go back to gasoline.

For a straight gaseous fuel only conversion the prices start at $157. You CAN do a multi-fuel conversion but I do not recommend it unless you really need the portability. Even if you do occasionally need to use the generator in the field you can use a portable propane tank.
 
  #7  
Old 09-15-15, 01:00 PM
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I went out today, tried to remove the spark plug, found it was stuck on there, so bypassed that step. Opened the fuel valve, no leaks for 5 minutes. Started fine with recoil start, ran for 10 minutes, no problems.

Will see about the avgas, or at least some ethanol-free gas to flush it out.

Will also look into the propane conversion. I have a propane cylinder for the house, but I don't know what the propane company would think about me tapping into that to run a line to the generator. I wouldn't want the generator permanently hooked in.

What kind of run time (estimated) would I get from a standard grill-sized propane tank? Am I allowed to ask for recommendations for brands for conversion kits? Is it a DIY-friendly project?

Thanks!
 
  #8  
Old 09-15-15, 06:04 PM
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Generally your propane company loves it when you tie in a device that consumes propane. It will depend on whether or not you own or rent your tank and associated equipment.

A gallon of E-10 gasoline has about 110'000 btu per gallon. A gallon of liquid propane has about 84'000 btu so expect to use about 25% more gallon per gallon. A 20 pound grill tank holds about 4.7 gallons of liquid propane when full though many popular filling places are notorious for only filling them partially to about 3.5 gallons.
 
  #9  
Old 09-16-15, 12:55 AM
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I don't know that I would try to run a 7kW generator on a 20 pound barbecue tank as it may cause the tank to frost over due to the higher withdrawal rate. For that generator I would rather see a 40 pound tank as minimum.

US Carburetion has the most options for converting a gasoline engine to propane. It is definitely a DIY job. Generator Conversion Kits to Propane and Natural Gas.
 
  #10  
Old 09-16-15, 08:48 AM
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I have a 420# propane tank that's used right now for cooking and a gas fireplace. I figure that should be more than sufficient. I notice that some of the US Carb kits are for high pressure propane and others are for low. How do I know which I have?

It would be nice if I could also hook a propane grill in, when I don't need the generator. Something like a propane spigot that I could tap into with either when it's needed. Is there a specific device I should ask for or a term I should use when talking to the propane company about getting set up?
 
  #11  
Old 09-16-15, 09:31 AM
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You have to look at your regulators to see what pressure you have. But if you are going to have your gas provider do the work it doesn't matter so much. They'll figure that out for you but if you tell them you want the option to hook up a grill that's easy to do. I have a shutoff valve and a 12' hose with another shutoff valve at the end which I can hook to anything (like a grill or cooker).
 
  #12  
Old 09-17-15, 08:04 AM
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Thanks for all the help and advice. You guys have been amazing! I've got a call in to the propane company and will probably be giving US Carb a ring to clarify some details and get the ball rolling.

One last question (hopefully): If I go with a tri-fuel conversion kit, and I use gasoline, should I just follow the recommendation of running some avgas through it to clear it out before going back to propane use?
 
  #13  
Old 09-17-15, 09:11 AM
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If you run gasoline you should go through the long term storage procedure, whichever you choose. Even if the float and jets for gasoline use are not used when running on propane they can still gum up causing a headache the next time you want to run on gasoline.
 
  #14  
Old 09-17-15, 02:48 PM
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Unless you plan on using this generator away from a propane source on a regular basis I would advise against a multi-fuel option. Keeping the gasoline option will retain many of the problems of gasoline that you want to be rid of by using a gaseous fuel.

As for the high-pressure vs. low-pressure options... the zero (pressure) governor that is the heart of the gaseous conversion can only accept an inlet pressure of about 1/2 psi. This is fine for a natural gas installation but for propane you will need an additional high-pressure regulator UNLESS you have a large, low-pressure regulator serving your house. In most cases a larger bulk tank will be place some distance from the house and the tank will have a primary regulator that lowers the tank pressure (usually in excess of 100 psi) to about 10 psi for the run to the house. At the house there may be a secondary regulator that drops the pressure to about 11-14 inches of water column (WC) for direct use in the various appliances OR the various appliances will EACH have a secondary regulator dropping the pressure to 11-14 inches WC. Sometimes there is an intermediate pressure regulator at the house as well as individual appliance regulators.

Propane barbecues all use an inlet pressure of 11-14 inches WC as will a low-pressure generator conversion. The main thing to remember is that all regulators have a maximum gas flow rate and you cannot put too many appliances on a low-pressure regulator without overloading it. Your gas supplier should have all the information on the regulator(s) in your installation to determine if you need an additional regulator for the generator.

This page shows a basic stationary propane installation. Stationary Propane Generator Installations
 
  #15  
Old 09-17-15, 04:35 PM
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Another thing you could consider is trying to find premium fuel that does not contain ethanol.
In Canada most stations carry it and I see it is available in America as well.

For me fuel related problems have dissapeared since switching fuels..
 
  #16  
Old 09-17-15, 05:11 PM
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I found a label on the regulator on my propane tank that mentions 9.5-13" WC, so I guess that means it's low pressure when it comes out.

We'll see what the propane company tells me, but I think at this point I'm inclined to just do the propane only conversion.

Thanks for your help everyone!
 
  #17  
Old 09-18-15, 06:48 AM
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Yes, 10" WC is a very common residential pressure. It's also what most gas grills use. One thing a professional gas company should do is look at all the appliances you may have running simultaneously and make sure your regulators and piping can provide enough gas.

I'm thinking once you convert your generator to propane you'll never go back to gas. It's so much easier if the gen only gets very intermittent use. No gas to worry about gumming up the carburetor and the fuel stores indefinitely so you don't have to worry about rotating your fuel every couple months.
 
  #18  
Old 09-18-15, 08:27 AM
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I don't think I'm going to run out of questions any time soon...

So, I'm looking at the US Carb Motor Snorkel, so I wouldn't have to drill the carb. Technically I guess it could be used as a tri-fuel with that set-up, per US Carb's website, though I don't intend to run gasoline anymore. I just know how I my luck is (I swear Mr. Murphy rents a room in this house ) so I'd prefer the drill-free option.

Anyway, if I don't drill the carb, I could theoretically return the generator to gasoline use in the future (say, if I want to sell it to some poor sap and buy me a nice new generator from somewhere other than Harbor Freight).

What's the best way to purge moisture from the gasoline tank, and keep moisture/condensation from accumulating, so I don't rust out the tank? Run it dry, let it air out til it's completely dry, seal it up and call it good? Would putting some large silica packets in there help? Or just straight up remove the tank, clean it out, and store it in the basement?
 
  #19  
Old 09-18-15, 09:02 AM
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I would siphon or pump out as much from the fuel tank as you can get. Then remove the drain bolt in the carburetor's bowl and open your fuel shut off valve. Then tip the generator to get as much fuel out of the tank as you can. Set it outside in the sun with the gas cap off and set those hydrocarbons free.
 
  #20  
Old 09-18-15, 10:41 PM
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I'm not totally sold on the "motor snorkel", especially on larger engines. Some people have had trouble being able to pass enough fuel through the snorkel for proper engine operation.

Drilling the carburetor, although a "never go back" operation, is easy. I used three or four bits of succeeding sizes in a T-handle tap wrench to ease my jet passage up to the necessary size to allow the gaseous fuel "spud" to fit. I don't think the whole operation of removing the carburetor, tearing it down, drilling and installing the spud and then sealing all the other openings with silicone sealant took more than about 90 minutes, maybe less.

But I do understand your position. I would ask on the US Carburetion forum Get help from the US Carb Techs - Forum about your specific generator. As for the gasoline tank, if it is easily removable I would do so to empty it completely and also remove the carburetor to ensure that ALL the gasoline has been blown out of it.
 
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