JD LX178Engine Stalling

John Deere LX178: Engine Stalling - I have changed the fuel pump, pulled the carb and cleaned completely, new gaskets, flushed/cleaned tank, new fuel lines, new filter, even backed off the gas cap to make sure it is venting. Started up, adjusted the carb, and it runs perfect. 10 - 20 minutes later, tries to die again like it is vapor locked. But this time, out of a reflex reaction, I pushed off the PTO clutch switch, and engine returns to perfect continuous running. Guessing I need to find an electrical glitch somewhere and I think I need to start with the charging system because the battery is not remaining charged - it is new also. I have a few things to check to see if the charging system is working, but need to locate the glitch with the electrical people somewhere in the system. Based on what I have told you so far, any first location places stand out to start on?

You need to get a wiring diagram of your tractor's electrical system. You may have a stator with a rectifier/regulator. Your battery voltage drop is probably causing your engine stalling. Using a volt meter set on dc volts and the engine at 1/2 throttle or better you should see 14-14.5 volts across your battery terminals.
Could be a diode used in the charging circuit. Your JD dealer may give you a copy of the wiring diagram. I have them for the 317 and 318 JD's. Hal

My two cents. Go on Ebay and enter you tractor in the search. You can pick up a CD with PDF files with all of the manuals you need for your tractor. About $15.oo for cost and shipping. Jeffcat

The rect/regulator on tractor for the kawasaki eng is not you're normal 3 terminal reg as used on kohler,briggs & tecumseh eng,the reg is a strange bird in that it has an internal circuit to monitor voltage or current in charging circuit & on tractor,internally in reg this circuit may/may not disconnect dc output from battery when it detects a low voltage/high current draw condition to protect reg/alt stator in addition to lighting dash light.Most of the operating sw's/safetys sw's & indicator lights connect to the interlock module on back of dash,problem could be loose/dirty connectors in wiring harness,loose/dirty connections at module,loose/bad connections on pc board that are sensitive to heat/vibration,bad parts on pc board,clutch coil going bad & drawing excessive current,short to chassis in wiring harness when tractor gets hot.You may need jd tech manual & kawasaki manual to troubleshoot/repair charging circuit problem OR leave for local jd dealer to repair.

If you don't have a wiring diagram for tractor do a goggle search john deere lx178+wiring diagram,in the 6 pics that come up print the 5th & 6th pics(this is wiring diag for tractor split in 2 pcs)at the very least you'll be able to check alt output back to battery & check voltage output for same,problem might be as simple loose connection in wiring harness where alt output connects to battery cable or fuse link in battery cable going bad & disconnecting alt output from battery,if link going bad or affected by heat,alt won't charge battery BUT will still power tractor wiring,interlock module board & clutch,the output from alt alone may not be enought to maintain clutch/rest of tractor elect demands,if main cable fuse link starts to open/opens,voltage on elect system with pto on may drop low enough for coils in pto/ign relays to start dropping out causeing the stalling problem you have.

Very Tech response - the one line that stood out to me here was "leave to JD dealer for repair." I like that one the best when it comes to finding those straying little electrical people causing problems. Thanks for your input.

I noticed that response myself, and had to ask...why are we on this forum? Methinks it is because we want to fix our equipment ourselves and are looking for advice and information to help us in this quest. Then too, there is the high cost of going to the dealer for every problem that arises. At over $75 per hour, the cost can quickly exceed the value of the tractor or mower or whatever else. I"m with you! I will do whatever I can to fix it myself before I turn it over to the dealer. Then too, the last time I went to a dealer, I was told to leave my equipment there and they would let me know what it needed in about 3 months!!! NOT acceptable!

Solved the electrical problem - located a .pdf service manual download for $20 and used the meter until I tracked down a burned out link in the rectifier 6-pin plastic harness. Replaced the harness and now charging the battery successfully. Been smilin' and mowin' for 3 different times in the yard until last evening when it died again - just like vapor lock. Pushed it to the garage, went out and started first thing this morning and it ran perfect for the 15 minutes needed to finish the job. Now contemplating my next step. Again, new fuel pump, new gas lines and filter, and pulled carburetor to clean and set-up idle have already transpired. Don't think I need it and the mechanic in me does not like to throw parts at something to fix it, but leaning toward the carburetor next for replacement.