Small generator problem

[Bad Wolf]

Now that Irene has passed I have time to tackle some problems. My little 2 stroke 900 watt generator initially worked fine but then it would die after 10-20 minutes. Fortunately this was not my primary generator. It does this whether it has a load on it or not. Its acting like it’s starved for fuel but it has a strainer on the fill opening and it was fresh mix. After it sits for a few minutes it starts right back up but then dies in another few minutes. The longer it sits, the longer it runs.
I’m going to drain all the fuel out of it, slosh some fresh mix through it and drain/blow out the carb.
Any other thoughts?

 

[Renaissance]

How does it run with the tank cap off?

 

[maverick06]

Agreed, check the tank cap, could be a venting issue.

Failing that
1) try new fuel with proper oil mix... that could cause problems
2) the carb could be gummed up. old fuel/dirt debris.

To "fix" the carb:
I would run it at full load for a while, so the engine really works hard... see if it can blow out the gunk.

Then clean the air filter.

Then I would stop by walmart and go to the snake oil aisle... then buy a can of carb cleaner, some fuel system cleaner all sorts of stuff, give it a try.

I would then disassemble the carb and toss it in a ultrasonic cleaner, clean the jets...

 

[heat seeker]

The newer gas eats rubber fuel lines. I'd pull the line off the carb and run it to a container and see how it runs out. It should flow freely and continuously. I'd figure the fuel line is defective, or the rubber bits that break off are blocking the inlet passage in the carb. We get that all the time on the tractor forums.

 

[velvetfoot]

I have a similar generator, if you want me to check something.

 

[MasterMech]

If the tank cap checks good (as soon as it starts to surge, pop the cap and see what happens.) then grab a cheap neon light type spark tester. Connect that and watch the genrator run. When it dies you will see if you still have spark or no. The symptoms you describe could be attributed to a failing ignition coil.

 

[Bad Wolf]

Thanks,
The generator is brand new. I ran it several times at the beginning for 4-5 hours straight. Then it started acting up
The fuel is brand new jsut made up for the occation, same mix as the chainsaw (50:1)
I tried the fuel cap thing it does the same whether the cap is on or off.
I'm thinking maybe some crap that was left in the tank and worked its way into the carb.
One more project for the weekend.

http://www.giobikes.com/Generators/GIO-950w-Mini-Generator/

 

[velvetfoot]

Wow, 20 bucks less than my Harbor Freight version.
Although I did not check for it on mine, there was some feedback on the HF site that there was some crap in the tank when new. Maybe it never got to the carb on yours, just clogging the pickup? I've never drained the fuel yet on mine-just let it run out; there doesn't seem to be any exposed line to remove. Perhaps you could pick up the whole thing, turn it upside down and empty into a funnel.

 

[maverick06]

looks great and the price is good too.... BUT the shipping cost is terrible. I havent gotten my $89 one from HF yet.... but thats still the cheapest thing available.

 

[Renaissance]

Maybe some kind of intake or exhaust leak which presents itself under heat expansion?

 

[velvetfoot]

The HF model was 89 during Labor Day, but more now.
The 20% coupons say they're no good for generators.

 

[velvetfoot]

For what it's worth, I just drained the fuel out of my HF 800 watt generator.
I first tried turning it upside down and pouring it into a big funnel.
It worked, somewhat, but even though it was totally upside down, it still did not get all the fuel.
There was also some fuel spillage.
To get the rest out, I put it on a couple of 5 gallon buckets, took off the fuel bowl, and let it drain into the funnel.
To finish it up, I put a piece of 2x4 under one end to angle it towards the carb.
Next time, I would do the last thing, angle it towards the carb, and just leave it drain.
It only holds a gallon or so.
I tried to start it after, but it wouldn't start, so I guess that means success.

 

[Bad Wolf]

I may have it fixed (crossing fingers).
I futzed with several things:
The fuel line looked kind of kinked so I replaced it with heavier wall tubing. Nothing changed.
I cleaned out the carb. Nothing
I looked at the plug and noticed that the center electrode was loose and sliding in and out. That can't be good. Got a replacement AC plug. Still no change.
I removed the fuel shut off valve and there was a small tube like screen about 1/4" in dia. and an inch long with very fine mesh. Removed that, reassembled it and its been running for 3 hours so far with a 500 watt load.
It seems like a poor design if an inlet screen can restrict flow to the point of starving the engine to death. I'll try putting it back tomorrow and see if it starts shuting down again.
Going forward, I'd like to put a hard 90 in the fuel line to eliminate the kink that is still there. Maybe I can find a small in line filter but there is already a fine mesh screen on the fill opening so that might be redundant. Lastly I'd like to put in a "T" in the fuel line and see if I can rig a 2 or 3 gallon fuel tank so I can get 10 to 12 hours run time. That way I can hook it up to the TARM and get a full nights sleep. Provided I need a generator I the first place. I'm thinking ice storm or snow storm where I need the heat. Irene was inconvenient but not a major disaster.

 

[velvetfoot]

On the HF, I've read of people taking off the gas tank and cleaning out the inside (air? water?).
You can't really see anything when you look down the filler hole because of the way the tank is shaped.

 

[Bad Wolf]

The tank seemed to be clean, there wasn't any dirt on the screen itself. I think its just a combination of a slight restriction in the line (kink) coupled with a very fine mesh on the screen. Once I get a hard 90 in the line I'll try putting the screen back in.
I've gotten pretty good at taking the tank off using a cordless drill and socket, 4 bolts, one clip: 35 seconds!!

 

[heat seeker]

The screen did it's job - keeping crud out of the carb. Now that you know it's there, that's where you'll look in the future. It's your fuel filter, in effect.