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John Deere JX75 running rich


grumpys toy's Avatar
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05-23-10, 04:50 AM   #1  
John Deere JX75 running rich

Good Morning,
I have a John Deere JX75 lawn mower with the Kawasaki 6.5 hp engine that I bought new in 99. Ever since the start of the season she has been running rich at first I thought it was old gas but I drained her put fresh gas in her & she is still running rich. Usually she will do the lawn twice before I have to fill the tank.
The other day I did the front & started to do the back yard & she died I pulled the plug out & it was black this happened the time before so I cleaned the plug put it back in & she still did not start.
I had just filled the tank before I started but when I checked she was out of gas! this is really running rich. Yesterday I bought a can of carb cleaner & this morning I took the carb off before I did that I made sure the choke was working it was.
I'm going to take the fuel bowl off of her as I think it may be the float or needle.
My question is does anyone have any other suggestions on what it could be?. I just can't believe the way she is going through gas I even bought a new spark plug just to have one on hand as I know the thing is going to foil out half way through cutting.
Anyway any other ideas would be greatly appreciated? Thank you!
Will,

 
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05-23-10, 04:59 AM   #2  
It's probably the fuel/air mix since it ran well before the "sit time". I would use Sea Foam for something like that. Just add it to the gas.

You could always have an ignition problem, though. Something in the coil/wire/plug. A weak link in those areas can give you a blackened plug. But I would suspect a float valve not seating. That will account for everything you have.

I would put the Sea Foam in it and run it for a couple of tanks full. If you still have the problem. I would change the float and valve together.

 
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05-23-10, 10:43 AM   #3  
Posted By: marbobj It's probably the fuel/air mix since it ran well before the "sit time". I would use Sea Foam for something like that. Just add it to the gas.

You could always have an ignition problem, though. Something in the coil/wire/plug. A weak link in those areas can give you a blackened plug. But I would suspect a float valve not seating. That will account for everything you have.

I would put the Sea Foam in it and run it for a couple of tanks full. If you still have the problem. I would change the float and valve together.
Thank you for your help right now I took the carb off her & took it apart I held the float closed & blew into the the line & it worked fine. So I cleaned everything with carb cleaner all the little holes also before I took her off I checked the choke & that was working so I'm just cleaning everything I can but not taking it apart except for the float & needle. Right now I have the float in a small bowl of water to see if it sinks but so far she is floating.
I'm not sure if I'm going to put her back on today (I took a ton of pictures as it is a pain the rods & springs) anyway if she still is acting up I'll buy some of that sea foam as I heard that is fantastic stuff I have never used it before.
I just wish I saw something when I took the bowl off cause I would of bet it was the float I mean I did not touch any adjustment screws & like you said last year she ran great.
Once again Thank You very much!
Will,

 
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05-23-10, 11:58 AM   #4  
Assuming it to be the float, Will..

Those things don't always fail altogether, in other words the float may not sink in liquid and use gasoline to check its buoyancy.

If the mixture is just rich enough to cause the blackened plug, but the power is still there, you may just have enough fuel going past the float valve to raise the fuel level in the bowl.

When you hold the float up against the valve to check its sealing, just use a very light pressure and see if you still get a little dribble.

 
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05-23-10, 11:40 PM   #5  
You might try replacing the air filter, even if it looks good.


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

God bless!

 
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05-26-10, 09:39 AM   #6  
Posted By: marbobj Assuming it to be the float, Will..

Those things don't always fail altogether, in other words the float may not sink in liquid and use gasoline to check its buoyancy.

If the mixture is just rich enough to cause the blackened plug, but the power is still there, you may just have enough fuel going past the float valve to raise the fuel level in the bowl.

When you hold the float up against the valve to check its sealing, just use a very light pressure and see if you still get a little dribble.
I checked the buoyancy in gas as you said I even let it sit overnight & she was fine don't know if this is right but when I took the float out of the gas I shook it to see if I could hear anything in it nothing.
I put her all back together put a rubber hose on the fuel intake tipped the carb upside down blew into it & no air got pass the needle then turned her right side up blew into her & air went in.
So after all this I put her back on & today I tried starting her it started right up but then it was running rich. What it does is misses or rough idel when I try to slow the engine down with the lever it dies it only runs in high but rough.
Having said this when I take the blade brake clutch off & the blade start turning she runs fine!. Anyway after about ten min running & boy does it make your eyes water I pulled the plug out & once again it was black.
What I did notice is the lever on the carb that is attached to a rod & spring that goes to the governer is moving back & forth on it's own. Now I'm thinking it is the governor or one of the springs to it!. To tell u the truth I don't even know what the governor does? I did check the spark & she has a nice one.
Will,

 
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05-26-10, 09:48 AM   #7  
Posted By: cheese You might try replacing the air filter, even if it looks good.
I replaced the air filter & sponge or what ever it's called that goes around the air filter right before the season I even re-checked it before I tried starting it after doing the carb. What I don't understand is John Deere recommends soaking the foam in motor oil then ringing it out. I would think this would impede the air flow.
I can only go by my 57 Chevy Bel-Air that I brought back to original with the original 283 I put the oil bath air cleaner on her filled it with oil & not only did it leak on my nice rebuilt engine but I also lost power. So I drained it wiped it all out but put the oil bath air cleaner back on her (as I show her in original class so she has to have it) but with out the oil in it I got my power back.
Thank you very much for your suggestion.
Will,

 
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05-26-10, 03:36 PM   #8  
Try running it without the air filter & maybe even try a new plug in it... For some reason, these engines are really sensitive to spark & air even if they look O.K. when you inspect them... Roger

 
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05-28-10, 05:21 AM   #9  
Posted By: hopkinsr2 Try running it without the air filter & maybe even try a new plug in it... For some reason, these engines are really sensitive to spark & air even if they look O.K. when you inspect them... Roger
Good Morning Roger,
Thank you for the information I will try what you said as a matter of fact I was reading that the original spark plug that it came with is an NKG I put a Champion in it the numbers cross matched but I never have been to keen on Champion.
Once again I cleaned the plug yesterday started her for 10 min. she was again running rough & died on low throttle when I took the plug out again it was black but I also noticed that the linkage hooked from the governor to the throttle was moving back & forth like a spring is weak I'm not sure if this has something to do with the plug.
One other thing is on the Champion site it says gap at .30 on the NKG site it says .25 & since like normal for me I lost the owners manual I go buy what they say. Anyway I'm going to the parts store today & seeing if they have a NKG plug for her cause this is getting crazy & I really don't want to tear her down to get to the governor until I try everything else.
Thank you for your help.
Will,

 
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05-28-10, 07:26 AM   #10  
I don't think I would tear into the governor to fix a blackened plug, Will. That is pretty much fuel/air by what you've described.

From what you did with the float/valve, that pretty well clears it. With your air filter in good shape, there must be something in the idle circuit that's flooding it. Do you have a mixture screw on that carburetor?

The oil in a foam air filter is what traps the dirt particles in the air flow. For that type of filter the oil has to be in there.

 
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06-02-10, 03:17 AM   #11  
Posted By: marbobj I don't think I would tear into the governor to fix a blackened plug, Will. That is pretty much fuel/air by what you've described.

From what you did with the float/valve, that pretty well clears it. With your air filter in good shape, there must be something in the idle circuit that's flooding it. Do you have a mixture screw on that carburetor?

The oil in a foam air filter is what traps the dirt particles in the air flow. For that type of filter the oil has to be in there.
Good Morning,
I went to the John Deere shop to get the original spark plug for it. The guy out there told me there are no adjustments for the carburetor I have no idea if this is true as there are screws on it but not knowing what is what I don't want to play with them.
What he said was my problem was the foam filter that goes around the air cleaner he thinks I put to much oil on it & to run it with out it.
So I did this & also bought a new foam filter as he said they are pre soaked from the factory. Anyway I tried it without the foam filter & the new plug & once again right away it ran rough with in 10-15 min. I checked the new plug & it was black again!. Having said that I checked the spark (not sure if I'm doing it right) but it looks good but I'm wondering if it's not my coil or what ever it's called.
What I don't understand is why when the blade is turning or clutch brake off she runs fine? but with the clutch on she only runs in high also why I'm going through a tank of gas & this is just cutting the front?. He also said that the springs running off the governor never wear I find this hard to believe.
Anyway the grass is getting tall so I'm going to try her today I'll go & buy some of that sea foam & put it in the tank before I do maybe there is so much carbon built up inside her. I was even thinking about buying a new carburetor but unless I know for sure I don't really want to spend the money. One other thing he said was to go to leaner jets but this too I don't understand as before this year she always ran great.
I'll let you know what happens latter once I cut the grass & with the sea foam in her.
Thank you for the help.
Will,

 
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06-02-10, 06:21 PM   #12  
If you soaked the precleaner too much, the oil probably also soaked into the filter element itself and is causing your problem. Have you tried running it without the air filter at all yet, as recommended?


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

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