Generator help

Merry Christmas y'all!

I'm visiting my family (3 hrs. away from my home) for the holiday and have been trying to help my father out with a few odds & ends while here. This morning before our big family lunch I was working on a generator he has that he can't get started. Said he was running it awhile back and it just stopped and he couldn't get it started after that. Simply little 2-stroke chainsaw engines are no problem, but I just don't know much about diagnosing or repairing 4-stroke. The engine will pop and fart and turn over slowly a few times and act like it wants to wake up, but no dice. Every couple of dozen pulls it sounds to me like it's backfiring or just blowing a loud burst of air out the muffler. I've tried every combination of pulls and chokes and other misc. I figured I would pull the carb apart and clean it out, but it just doesn't seem like a carb problem to me. Again though, I don't know shi* about 4-strokes.

Any advice on what the problem may be?

 

Drop the main fuel bowl its probably full of crud. If it doesn't have a fuel shutoff pull the line loose and route it to a drain pan or elevate above the fuel tank(if you don't plan on fresh gas)
What kind of engine?

 

As basod said, check out the fuel first. Could also be a timing or valve issue with the occasional pop thing going on.

Post up the engine info and I can forward the manual if you'd like. Have to go into work for a few hours this afternoon but if I have time to fire up the computer I can get the manual to you from there.

 

Do you have a way to test the spark to see if it is constant with every pull ? If thats good then go for fuel problem as Basod said.

Merry Christmas to you.

 

Sounds good. Let's get this fixed if we can. Sorry, but all I can be cheerleader for this. My only card (i.e. put in fresh fuel) was already played.

 

Eliminate one variable first. either get a plug that is currently running something else or try the plug you're working with in that piece of equipment.

From there, new fuel as stated earlier and disconnect the fuel line. Most generators are overhead tanks with gravity flow. Make sure fuel flows. You can pressurize tank with light air if needed. If that checks look at the carb. If gravity fed should have a bowl, Pull the bowl off and check for crud. Jet in the center and needle valve are the normal trouble areas. Clean and reassemble. I use a hand over the carb with air cleaner off, should see the fuel draw in then.

 

The fact that it was once running and then quit would seem to point to a timing/ignition issue unless trash was sucked into the fuel system.

Would be helpful to know what you are working on.

 

Restricted fuel supply acts the same. Pops and empties what's available but can't recover quick enough to keep a steady supply of fuel. Some generators have fuel shut offs too so make sure it is completely open. I have had several friends call and when I got there the fuel was cut off or only just barely open. Normally something simple.

 

Some generators have a low oil shutdown switch. Make sure it's full of oil. If the level is right at the edge of tripping the switch you could see similar symptoms.

 

I was just thinking the same thing, that would account for it shutting off as well. Both my generators have them.

 

On our old generator, the low oil shutdown switch went even though the oil level was good, I couldn't use it (wouldn't start) until we had a new one installed.

We bought it just before the ice storm of 98, another problem I had about three years ago was it would only run with the choke at the halfway position, the carb needed a real good cleaning, it's been great since then.

 

Thanks for the suggestions everyone - I was in a hurry when I started the thread and should have given more info as I had done the basics already. The (overhead) tank is full of fresh fuel and it flows freely to the carburetor. The fuel shutoff valve is fully open. The oil level is good, but in regards to that switch going bad, I assume that eliminates spark, correct? So, if it were a bad level switch I wouldn't get any fire in my assumption.

It's (very much against my advice) a Chicago brand generator from Harbor Freight.

Tomorrow I'll pull the bowl off of the carb to get a look . . . ran out of time today.

Thanks!

 

Have you tried forcefully applying your right foot to the left side of the crankcase? Sometimes that helps.

 

I had a little more time today to look at the generator (bit the bullet and took it home with me). Fuel flows freely from the tank to the carb. I thoroughly cleaned the carburetor, but found no crud or anything other than a new-looking carb on the inside. I did find some nested/dead bugs in the breathing chambers on the carb mounting faces, but after putting it back together, no change. With a spark tester attached there appears to be solid and consistent spark. Disconnecting the oil level switch made no difference.

I'm heading into town to get a new spark plug to replace the cheapy one that was installed just to be safe and eliminate that as a variable. Here is a video of how it's acting. On the left side you'll see the air box which is open (cover & filter removed). You'll see some puffs of smoke come out of it occasionally. I switch back & forth between choked and not-choked because each time after messing with it and leaving it choked I remove the spark plug to find it very wet...

Thoughts? I know very little about 4-strokes, but this just seems like a timing issue to me? Thanks!

 

Do you smell fuel in the exhaust when your pulling. After a dozen pulls if the carb is working properly you should smell gas...... Does it have serviceable valves? Can you pull a valve cover to make sure one isnt stuck open?

How about a touch of starting fluid? If it runs on ether you know its the carb.....

 

Seems lean after watching the video?

 

Hmmm, is it smelly from gasoline? It's a fuel issue, most likely. The backfiring seems to be like it's too rich.

Timing shouldn't have changed, but it's harbor freight, so who knows.

 

Kinda acts like a stuck or dirty valve that's not seating properly. Have you checked compression?

 

I agree, Compression check is the next thing. Sometimes the valves will get stiff from long term sitting or a piece of carbon falling off the head can partially hold a valve open.