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Honda Generator only runs fully choked


sched's Avatar
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06-03-07, 03:01 PM   #1  
Honda Generator only runs fully choked

I searched for this problem but did not find an answer. Here goes.

Have a Honda Generator with a GX140 engine on it. It will only run when fully choked. Open the choke and it dies. You can hold the throttle stop against the idle screw and it idles just fine with the choke off. Let the throttle move off of idle and it dies. I figured clogged main jet in carb or vacuum leak at carb mounting but a vacuum leak probably would not let it idle.

I took the carb apart and put the plastic parts aside. The needle valve on the float looked good. I did the spray carb cleaner thing plus compressed air but it really wasn’t too dirty inside. I did not see any clogging in the main jet. I put it all together and it acted the same, no change. Only runs on full choke.

The valve adjustment on this engine was tight so I adjusted the overhead valves with no change. I yanked the head to inspect the valves and cylinder and there does not seem to be a lot of wear on this engine. I squirted parts cleaner juice at the back of the valves and there was no leakage.

Replaced plug for giggles. No change. Also checked vent in carb and gas cap. All ok.

Any other suggestions.

 
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drm01's Avatar
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06-04-07, 05:07 AM   #2  
Still sounds like you've still got a stopped up/restricted fuel feed somewhere - which you probably already knew. How old is the generator did it ever run okay without the choke on? If it is a fairly new generator and has never ran without the choke, it could be just a flat out defective carb with one or more of the fuel passages undersized. If you had another carb you could put on the generator to check it out.................

The only other thing I can think of is does it have a fuel filter/fuel line that needs changing or is the fuel outlet from the gas tank partially clogged?

Danny

 
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06-04-07, 07:18 AM   #3  
Thank you for the reply.

Yes, the generator did run welll at one time. It was given to me to repair in trade for a big beasty old Sears (Roper) garden tractor.

The carb is always full of fuel when I remove it. You would think it would run full bore until it ran low on fuel in the bowl if the fuel was restricted but not shut off to the carb.

The machine is late 80's vintage. There is remarkably little wear in the cylinder bore. The exhaust valve was a bit rough. There is a bit of recession in the face of the exhaust valve, but didn't leak when I sprayed parts cleaner behind it. The seat in the head is cherry. There seems to be ok compression but this engine does have a compression release built into the cam so you can't tell. There is good bounce back.

This one has me on the ropes. I will recheck for a fuel restriction all the way from the petcock to the main jet once more.

 
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06-04-07, 10:17 AM   #4  
In my oversimplified look at this (not because I am hiding vast amounts of knowledge but because I don't know) the running at idle could be because there is a seperate idle circuit. When it tries to go off idle but only runs on full choke would be due to either too much unmetered air or lack of fuel delivery? If all my gaskets or sources that would lead to unmetered air past the carb were in order my bet would be in the carb and would do a good cleaning.
As folks should know about me I use this forum as learning experience for me but I am trying to help :-)

 
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06-04-07, 07:51 PM   #5  
Thanks for the suggestion.

I'll post back after I soak the carb and put everything back together.

 
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06-12-07, 06:00 PM   #6  
This thing is driving me crazy!

I soaked the carb in the real stuff this time and all the passages are clear. I blew through all the holes and they are all open.

She idles fine but will die if allowed to rev to full running speed (portable generator) she will die. She runs pretty good with the choke fully on or closed. I triple checked for air leaks on the fuel side but if this were the case, it probably would not even idle.

I know it sounds like a clogged main (fixed on this carb) but I know it is clear from the jet to the nozzle holes.

Anyone had this exact problem and found a cure?

Thanks to those who have tried to help so far.

 
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06-12-07, 11:59 PM   #7  
Still a carb problem or air leak. Check the black plastic piece between the carb and the head. I've seen these crack and allow air to enter here.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

God bless!

 
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06-13-07, 04:32 AM   #8  
I looked real good at this plastic piece, what Honda calls an insulator, early on. I will take a closer look once again. I have never had a carb give me so much trouble. I am almost sure something is amiss in the high speed circuit even though it visually looks clean.

What is the best place to purchase honda parts online? The local dealer is over 18 miles away and a bit of a rip-off artist.

I found a place in Texas and a new carb is $58.00. Seems cheap.

Thanks for the help!

 
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06-22-07, 07:39 PM   #9  
Thanks to all who tried to help.

It was the carburetor. Even the nasty carb cleaner wouldn't unclog it. Ended up putting a new one on. It only cost me $58.00.

 
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06-22-07, 09:02 PM   #10  
Glad it is fixed and appreciate posting back, This place is my giant textbook and without knowing what fixed what it is like someone ripped out the last chapter :-)

 
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