QuestionQUESTION: I have an older LX188 that has done us right for many years. Last season I took it to a local small engine guy who cleaned the tank, changed hoses, filters and cleaned the carb. Everything was great.
This season the mower was acting exactly like last season with the engine loping or hunting in pretty much all levels of throttle. I pulled the carb, cleaned it pretty thouroughly and replaced it. I replaced the fuel filter, and check all the hoses including those for the fuel pump and carb.
I'm able to get it running now but only mow for about 10-15 minutes and the mower just shuts down and we must wait for it to 'cool' for a bit before it will restart. I noticed that if I time it right I can shut down the mower deck and let it idle for a few minutes and catch it loping or hunting again once it gets pretty hot.
What should I check now?
ANSWER: Hello Matt:
You can View a Breakdown/IPL of the Mower at this Site Addy, http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H and Enter the Model Numbers and Click Find. Then Select the Sectional File. Then Select the Section of the Mower you Wish to View Online. Check the Gas Tank Cap. Make Sure it is Venting the Tank Properly. Did the Shop Change the Pickup Tube in the Gas Tank? Did you Soak the Carburetor Overnight in Carburetor Cleaner? If No, then Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner (I Use Gunk). I have Found that Most People can Use a Breakdown/IPL and Disassemble the Carburetor Enough for Proper Cleaning. You Only have to Remove the Bowl, Float Pin, Float and Needle Valve and Any Adjustment Screws that Go Into the Carburetor Body. The Welch Plugs Do Not have to be Removed. Then Soak the Carburetor Body and Parts in a 1 Gallon Can of Gunk Carburetor Cleaner Overnight. The Can has a Parts Tray Inside it for the Small Parts. Once the Carburetor and Parts are in the Cleaner, you can Replace the Lid for Safety and to Prevent Accidental Spillage. Then Blow Out the Passages with Compressed Air. Install New Parts if Required. Operate the Mower as Usual. When it Quits Immediately Check for Fire at the Plug. If No Fire, then Check the Ign Module/Coil/Igniter. Remove the Spark Plug and Wrap the Threaded Section of the Plug with Wire, then Attach the Other End of the Wire to the Engine Block. Now, Remove the Coil Shut Off Wire at the Shut Off Switch. Check for Fire. If No Fire, then Remove the Cut Off Wire from the Coil (removal of the blower housing required) and Check for Fire. Turning the Engine By Hand (giving a Quick Twist with the Wrist) is Enough to Make the Coil Fire the Plug. If Still No Fire, then the Coil/Ign Module/Igniter is Bad. The Just Shuts Down Usually Means the Ign Module/Coil/Igniter is Heating up and Grounding the Circuit for Firing the Plug. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 9pm EST (US). My New Day Starts then. Thanks.
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: Thanks John for your quick and detailed response. I don't know if the guy changed the pickup tube, I'll check that too. Checked the gas cap, seems to be free of debris. Tried with the cap off as well, same issue.
I did not soak the carb overnight but just picked up a can of Gunk today and have one soaking in it right now from a push mower thanks for tip on that one. Will do the same for the Deere asap.
Not sure what a Welch Plug is and couldn't find it on the IPL.
The remainder, checking for fire at the plug and the Ign module/coil/igniter sounds a bit more detailed than I'm comfortable with, may have to have the mechanic do that if cleaning the carb does nothing.
One last thing, about adjusting the carb; any information you can give me on what adjustments should be? Once I take all the jet screws out and clean everything, when I put them back in how do I know where they should all be set? How do I tune it to keep it running smoothly?
Thanks.
Matt
ANSWER: Hello Again Matt:
A Welch Plug is the Small Round Plugs that are Pressed Into the Housing to Cover Internal Ports and Passages of the Carburetor. As for the Ign Module/Coil/Igniter Check; it is a Simple Process. I Just Reviewed the Breakdown for you Engine and if the Engine is Not Firing the Plug when the Engine Shuts Down after Running 10 to 20 Minutes, then the Igniter (JD# AM105574) is Most Likely Bad. It is Rare for a Coil to Go Bad Unless the Ign Module/Igniter is an Internal Component of the Coil. If No Fire at the Plug, then Replace the Igniter. On your Carburetor there is Only 1 Air Mixture Screw. The Idle Air is the Only Mixture Screw Shown in the Breakdown. Turn this Completely In Until Snug. Turn the Screw Out 1 1/2 Turns. Start the Engine and then Adjust In or Out Until the Engine will Rev from Idle to Full Throttle with Hesitation when Throttling Up. Just in Case I am Looking at the Wrong Carburetor, here is the Complete Instructions on the Carburetor: ****All the Carburetor Adjustments are the Same for Lawn Mower and Trimmers. There are Several Location for the Air Mixture Screws. The Idle Air Mixture Screws are Usually Located at the Top of the Carburetor Bowl and the Top of the Carburetor Body. If the Main Air and Idle Air Mixture Screws are Side by Side on the Side of the Carburetor, then the Idle Air is the Farthest from the Engine. The Main Jet Air Mixture Screw is Located in the Bottom of the Carburetor Bowl or Beside the Idle Air Screw on the Side of the Carburetor Body. Some of the Older Model Carburetors have the Main Jet Mixture Screw Straight in from the Top of the Carburetor Body (this is Rare anymore). If you have Cleaned the Carburetor (Disassembled and Soaked Overnight in Carburetor Cleaner (I Use Gunk). Then Blow Out the Passages with Compressed Air and Install a New Kit if Required. Now Setting the Air Mixture Screws: ****Turn the Idle Air and ****Main Air Mixture Screws In Until SNUG **Do Not Jam** Then Reverse Both Screws 1 1/2 Turns. Holding the Throttle Full Open, Start the Engine. Turn the Main Air Mixture Screw Clockwise Until Proper Revs are Obtained. Occasionally you May have to Turn this Counter Clockwise to Achieve the Proper Revs. Now Allow the Engine to Idle. Set the Engine Idle Screw (Not Idle Air) so the Engine will Stay Running if Required. Now Set the Idle Air Mixture Screw so there is No Hesitation when Throttling from Idle to Full Throttle. Reset the Engine Idle if Required.**** Do Not Forget to Check the Carburetor Shut Off Solenoid. If it is Heating Up it will Shut Off the Gas Flow to the Carburetor Jet and Shut Off the Engine. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.
Good Luck
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: John, I hate to ask since I know you're busy and this is volunteer basis, but if I were able to get a pic of the actual carb (since there are no markings like listed that I can see on the IPL) would you be able to identify the screws you mention?
I know the Engine Idle Screw which is at the top mounted horizontally pushing against the butterfly valve. This screw has a spring around it. Just below that is a single screw at an angle who's jet penetrates the Engine Idle butterfly and is closest to the engine. This screw also has a spring. There is another screw above the bowl mounted vertically more or less in the center of the carb. No screw on this, it seems to have been snugged to the body and looks to have a flat head slot with a hole in the center, on the shaft it has two tiny jet holes. Lastly, the screw from underneath that holds the bowl in place is mounted upside down and vertically.
One last screw mounted horizontally on the front (away from the engine) has a small tube which when turned counter clockwise let's gas pour out.
I hope this tells you what I'm seeing as best I can describe. Again, I wasn't able to find any numbers on the carb anywhere only the manufacturer I believe, I forget it now but begins with 'M'. I'm not sure which diagram to look at for the IPL to be sure I'm adjusting the correct screws.
Before this last cleaning (still soaking now) what I believe to be the Idle Air screw (second in my description) turning to extremes and everywhere in between seemed to make absolutely no difference whatsoever when the mower was running. I've tried adjusting that screw at idle and WOT with no changes at all. So far the only changes I can make to the engine speed or idle roughness are with the Engine Idle Screw. Of course, without the correct mixture the engine lopes pretty bad resulting in no mowing.
Thanks again!
Huge help so far!
AnswerHi Matt:
Use the #24 Carburetor (Marked 32206 or 32411)(LX188) File. The Only Adjustment is the Idle/Pilot Air Mixture Adjustment. This is #6 (should be the 2nd Screw you Described) in the #24 Carburetor Breakdown. Make Sure to Blow Out the Passages of the Carburetor and the Jets with Compressed Air. Having No Main Jet Adjuster means the Carburetor and Jets Must be Clean and Free of Any Restriction or the Engine will Lope when Running. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.
Good Luck
Respectfully
John
