I love a good electrical troubleshooting challenge but this one has got me stumped. I am working on a friend's John Deere with a Kawasaki FD611V-BS01 engine. This mower came to me with a no-start complaint that I identified as due to no spark on either cylinder. My experience with these engines (and my online research) led me to replace the time delay relay ($13 on Ebay). I replaced it and the engine started immediately. Woohoo, I'm a genius??? 3 hours later, I attempted a second start and I was once again in a no-spark condition. (forget about that genius thing!) Since the relay was so inexpensive, I ordered another time delay relay thinking I got a faulty relay the first time. This relay failed to restore spark. The next component in the troubleshooting guide was to replace the igniter ($66 on Ebay). When I pulled the original ignitor, I found a hole in the casing and what appeared to be heat damage visible inside it. The new igniter restored spark immediately. About 2 weeks later, the owner reported loss of power which we quickly diagnosed as no spark on the left side cylinder. The engine would run on the right side cylinder but with obvious lack of power. Prior to replacing anything, the right side then lost spark. GRRR!
I replaced the left side coil with a known good coil from another JD but no spark returned on that side. I tried 2 other time delay relays (neither of which were known to be good since they came off this engine during previous troubleshooting efforts) and no spark was restored. Other things I've checked:
1. both fuses on ignition switch circuit board are good
2. 12v confirmed to both coils (using the (-) wire as the return path)
3. condition remains after replacing spark plugs
4. oil switch disconnected to confirm it wasn't causing the no spark condition
5. Thermo switch disconnected to confirm it wasn't causing the no spark condition
6. Igniter plugs inspected to confirm no damage/bent pins or evidence of electrical anomalies
7. Inspected all accessible wiring for evidence of mouse damage.
I have not replaced the pulser coils yet because it doesn't seem that both would go bad in such a short time and the replacement of other components has (briefly) restored spark. It appears I have an issue other than pulser coils.
Any thoughts??? Help!!!
Thanks for any advice you can provide
JShep1102 (Jerry)
I replaced the left side coil with a known good coil from another JD but no spark returned on that side. I tried 2 other time delay relays (neither of which were known to be good since they came off this engine during previous troubleshooting efforts) and no spark was restored. Other things I've checked:
1. both fuses on ignition switch circuit board are good
2. 12v confirmed to both coils (using the (-) wire as the return path)
3. condition remains after replacing spark plugs
4. oil switch disconnected to confirm it wasn't causing the no spark condition
5. Thermo switch disconnected to confirm it wasn't causing the no spark condition
6. Igniter plugs inspected to confirm no damage/bent pins or evidence of electrical anomalies
7. Inspected all accessible wiring for evidence of mouse damage.
I have not replaced the pulser coils yet because it doesn't seem that both would go bad in such a short time and the replacement of other components has (briefly) restored spark. It appears I have an issue other than pulser coils.
Any thoughts??? Help!!!
Thanks for any advice you can provide
JShep1102 (Jerry)
