Jon Deere LX 188 bogs down

[Green Flamingo]

Dear Green Flamingo and Hank Koster -
I have the exact problems that you are having with your John Deere lx188. I have replaced the dirty fuel filter and checked the fuel lines. The fuel lines look in good shape but, how do I know if air is getting into the line that connects to the fuel tank? The fuel line after the filter that connects to the carb seems bone dry. I hope that you have solved your problems and can share your remedies with me. Also, Fish, how do I adjust the valves?
Many thanks

Leah,

Happy to say I have resolved the problem. After eventually replacing the fuel pump as well as cut the plunger off of the Solenoid, it was still doing the same thing. Surgeing and finally unable to run with the deck engaged. Since I'm not very confident taking apart little carbs, I took it to a mechanic I know, who took out the needle valves and soaked it all in combustion chamber cleaner for a few hours. Runs like a scared rabbit now.

I will say this: The govenor is extremely touchy on this machine. It can be adjusted by moving the plate that houses the throttle cable etc. One of the bolt holes is oblong. Just move it so slightly, tighten it and try it. If it's idling too fast or slow, do it again until you have what sounds like normal rpms. It may take a half a dozen tries.

Also, the fuel filter does not run full. At least on mine. Half full at best and this IS normal.

If you haven't removed the carb it is a bit of a pain. You will have to remove the bonnet, (there are two bolts on the sides which will require an extension), and then the black metal plate behind it (two small 10mm nuts) In fact everything in that area is 10mm so you won't need a bag of wrences. The carb mounting nuts are on the same bolts as this plate is attached to. In order to remove the carb you will need to remove the two bolts that hold the plastic air duct in place on the blower housing, which is attached directly to the carb intake, then VERY CAREFULLY, remove the throttle linkage plate and the carb at the same time slowly. You will have to remove the spring going to the govenor and finally the two little armatures that go from the throttle linkage plate and govenor to the carb itself. The one coming from the Govenor will have a little spring on it as well which must be removed at the same time. Pay very particular attention to what goes where. (I wish I had have taken pictures before - but you would be wise to do this) The choke linkage one has a bend in it so be sure you know which end goes where for reassembly.

Once you have the carb cleaned and reassembled, just reverse the process you used to take it apart. If you have any amount of dirt in there, I would also recommend pressure washing that area out after you remove the plate and before removing anything else. Things are very hard to see otherwise if they're covered in years of gunk. Do that before you take anything apart.

You may actually have to remove the govenor armature as well (I did in order to get the spring and connecting rod off and on) There is a hole in the govenor shaft from the engine. I marked the govenor lever with the hole position before I removed it and replaced it in the same postition.

So what have I learned from this 500.00+ exercise? It was not the plugs, or the coils, or the filters, or the fuel lines and it was not the fuel pump. It was a dirty carb all along. The first guy I took it to removed the bowl and said it was clean as a whistle. WRONG. It needs to come apart.

In any event, I have now what would be for all intents and purposes a brand new machine.

Oh, and the valve lash (which I did not do), is .06. You will need to bring each cylinder to TDC, and then adjust the lash with a feeler guage just so it pulls out with a slight resistance. To find TDC without tearing apart the whole shamoozle, just remove the plugs and click it over until the piston is as close to the spark plug hole as possible. Do this seperately for each cylinder. But honestly, unless they are making a lot of noise I think it's best to leave them alone.

I don't recommend dissasembly with a hot engine. When you take the fuel line from the carburetor, there could be a lot of fuel loss - directly on a burning hot muffler!

Hope this helps some. It is extremely frustrating. If you need anything more please do not hesitate to reply.

Cheers,

Rick

 

[Hank Koster]

Leah,

Happy to say I have resolved the problem. After eventually replacing the fuel pump as well as cut the plunger off of the Solenoid, it was still doing the same thing. Surgeing and finally unable to run with the deck engaged. Since I'm not very confident taking apart little carbs, I took it to a mechanic I know, who took out the needle valves and soaked it all in combustion chamber cleaner for a few hours. Runs like a scared rabbit now.

I will say this: The govenor is extremely touchy on this machine. It can be adjusted by moving the plate that houses the throttle cable etc. One of the bolt holes is oblong. Just move it so slightly, tighten it and try it. If it's idling too fast or slow, do it again until you have what sounds like normal rpms. It may take a half a dozen tries.

Also, the fuel filter does not run full. At least on mine. Half full at best and this IS normal.

If you haven't removed the carb it is a bit of a pain. You will have to remove the bonnet, (there are two bolts on the sides which will require an extension), and then the black metal plate behind it (two small 10mm nuts) In fact everything in that area is 10mm so you won't need a bag of wrences. The carb mounting nuts are on the same bolts as this plate is attached to. In order to remove the carb you will need to remove the two bolts that hold the plastic air duct in place on the blower housing, which is attached directly to the carb intake, then VERY CAREFULLY, remove the throttle linkage plate and the carb at the same time slowly. You will have to remove the spring going to the govenor and finally the two little armatures that go from the throttle linkage plate and govenor to the carb itself. The one coming from the Govenor will have a little spring on it as well which must be removed at the same time. Pay very particular attention to what goes where. (I wish I had have taken pictures before - but you would be wise to do this) The choke linkage one has a bend in it so be sure you know which end goes where for reassembly.

Once you have the carb cleaned and reassembled, just reverse the process you used to take it apart. If you have any amount of dirt in there, I would also recommend pressure washing that area out after you remove the plate and before removing anything else. Things are very hard to see otherwise if they're covered in years of gunk. Do that before you take anything apart.

You may actually have to remove the govenor armature as well (I did in order to get the spring and connecting rod off and on) There is a hole in the govenor shaft from the engine. I marked the govenor lever with the hole position before I removed it and replaced it in the same postition.

So what have I learned from this 500.00+ exercise? It was not the plugs, or the coils, or the filters, or the fuel lines and it was not the fuel pump. It was a dirty carb all along. The first guy I took it to removed the bowl and said it was clean as a whistle. WRONG. It needs to come apart.

In any event, I have now what would be for all intents and purposes a brand new machine.

Oh, and the valve lash (which I did not do), is .06. You will need to bring each cylinder to TDC, and then adjust the lash with a feeler guage just so it pulls out with a slight resistance. To find TDC without tearing apart the whole shamoozle, just remove the plugs and click it over until the piston is as close to the spark plug hole as possible. Do this seperately for each cylinder. But honestly, unless they are making a lot of noise I think it's best to leave them alone.

I don't recommend dissasembly with a hot engine. When you take the fuel line from the carburetor, there could be a lot of fuel loss - directly on a burning hot muffler!

Hope this helps some. It is extremely frustrating. If you need anything more please do not hesitate to reply.

Cheers,

Rick

I think I've solved my problem by buying a new carburetor and installing it myself. As Rick points out, this is a bit of a pain in the butt and this engine was clearly not designed to make it easy to get at the carburetor. The new carb was $210 with free shipping on ebay. It's possible the old one didn't need to be replaced, but after untold number of trips to the mechanic with lots of parts replaced and adjustments and cleaning to the old carb, this is actually a cheap way to go. So far, so good.

 

[Green Flamingo]

I think I've solved my problem by buying a new carburetor and installing it myself. As Rick points out, this is a bit of a pain in the butt and this engine was clearly not designed to make it easy to get at the carburetor. The new carb was $210 with free shipping on ebay. It's possible the old one didn't need to be replaced, but after untold number of trips to the mechanic with lots of parts replaced and adjustments and cleaning to the old carb, this is actually a cheap way to go. So far, so good.

Good stuff. Hopefully anyone else having this problem will find this thread and save themselves a lot of greif and money.

 

[Leah C.]

Hi -
Thank you for your kind responses! I removed by first carburetor tonight! I did take pictures so, I hope I can put it back. I am going to take it to someone and have it cleaned. What I think is a solenoid valve was attached to the carb. I left it on and thought the repair shop could check it, too. Does this sound right? (I am learning as I go....lawyer by trade but love working with engineers so, I feel compelled to try to fix it myself.) I am glad to hear that you both were able to fix your lawn tractors. Thanks to this forum, I have only invested a few dollars in a new fuel filter and 2 spark plugs (I don't know if they are gapped right!) so, hoping that a cleaning of the carb will do the trick. I need new gaskets for both sides of the carb. They are dry rotted. There is some residual, dried out gasket where the carb fits into the engine. Do you have a recommendation as to how to remove it? I want the new gaskets to have a tight fit.
I appreciate your assistance!

Leah

 

[Rokon]

Oh bullcheet....

Well, I cannot say anymore..... I might get reported........

That never happens... :laughing:

 

[Green Flamingo]

Hi -
Thank you for your kind responses! I removed by first carburetor tonight! I did take pictures so, I hope I can put it back. I am going to take it to someone and have it cleaned. What I think is a solenoid valve was attached to the carb. I left it on and thought the repair shop could check it, too. Does this sound right? (I am learning as I go....lawyer by trade but love working with engineers so, I feel compelled to try to fix it myself.) I am glad to hear that you both were able to fix your lawn tractors. Thanks to this forum, I have only invested a few dollars in a new fuel filter and 2 spark plugs (I don't know if they are gapped right!) so, hoping that a cleaning of the carb will do the trick. I need new gaskets for both sides of the carb. They are dry rotted. There is some residual, dried out gasket where the carb fits into the engine. Do you have a recommendation as to how to remove it? I want the new gaskets to have a tight fit.
I appreciate your assistance!

Leah

Yes Leah, that would be the solenoid. You can ask them to test it at the shop. With 12 volts applied across the terminals it should retract. If there is any question, simply ask them to cut the shaft off. It won't hurt anything at all. This is the fuel shut off solenoid, also known years ago as an anti-backfire solenoid. It is there to prevent excess fuel from getting into the system if you shut the engine off at high RPM. Mine always did backfire once in awhile after long hot use anyway. Remember to have them position the bowl on the carb so the solenoid is in the same position otherwise it may not fit or the wire will not reach it.

You will need to get the gaskets from John Deere. (you should get both for the front and the rear while you're in there), and they are #6 and #8. I will try to attach the parts layout. To remove the old gasget, you can get gasket remover from NAPA or most Auto Parts stores. It will probably come in a spray can. You don't really want to get any of this inside the intake manifold, so stuff a rag in the hole before applying it. I would personally spray some into a container and then apply it with a brush. Let it sit for 10 minutes or so, and then scrape it off with a PLASTIC scraper. Repeat as required. A plastic spoon or knife from a take out restaraunt is ideal for this. And don't get too much on your hands. It will eat the skin right off your fingers if it's on there for long. (experience speaking)

Hope all goes well, and looking forward to hearing about your progress.

View attachment Kentville@green-diamond.ca_20140814_112928.pdf

 

[Leah C.]

Hi - I took the carburetor in for cleaning. They took the bowl off and said it didn't look too dirty so they didn't clean it. They did cut off something on the solenoid. Put it back on and it ran for a few minutes and quit. I have removed the fuel tank and cleaned it. Replaced the fuel lines, fuel filter, air filter, and spark plugs. Based on your experiences and posts, I wasn't ready to give up on the carburetor so, I took it apart and cleaned it. My tractor now sounds very good and doesn't quit, even with the blades engaged. BUT...... it doesn't seem like the governor is working right. The rpms/idle sound good (after quickly adjusting that little screw on the carburetor) but, it only sounds like it has one speed. I have a choke position, rabbit and turtle. It doesn't seem like the governor is pulling the arm right to make sounds/changes as it goes through the three positions. It makes a slight change from rabbit to turtle but not from choke to rabbit. Sorry that I don't know the correct terms but hope someone can figure out what I am trying to say. I haven't cut the grass with the tractor yet because I am worried that running it too rich or too lean isn't good for the engine (like when you go up a hill, it should adjust and give a little more gas..?). I have taken the carburetor on and off about three times now and feel good that I have attached the arms from the carb to the governor right but....???? I adjusted the screw at the bottom of the governor that holds the cable that runs from the orange choke lever to the governor so I can get the orange lever to go into the three positions..... I would appreciate any help!
Leah

 

[Green Flamingo]

It sounds like you have a couple of things going on there. The governor on these machines is extremely picky. To set it, first loosen the bolt, then put the throttle to maximum (with the engine off obviously), and then tighten the governor arm while holding it counter clockwise as far as it will go.

You will also notice on the plate the holds the throttle cable, that one of the holes (on the right looking from the front) is oblong. You can adjust this as well to increase or decrease the governor action and rpm.