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JohnF2015
JohnF2015, Small Engine Technician
Category: Small Engine
Satisfied Customers: 1017
Experience:  Owner/Service Technician at S & J Small Engines
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CV 740S stop running while mowing grass wildcat mower.

Customer Question

CV 740S stop running while mowing grass scag wildcat mower. Starts back every time but stops after 1 or 2 seconds. Put timing light on spark plug wire and flashes while starting and running and then goes out 1 or 2 seconds later, ever time.
Submitted: 1 year ago.
Category: Small Engine
Expert:  JohnF2015 replied 1 year ago.
Have you tried your timing light on both cylinders? Do you get any different results?
Customer: replied 1 year ago.
Yes. It does the exact same thing on both cylinders.
Expert:  JohnF2015 replied 1 year ago.
Does your engine have Smart Spark on it?
Customer: replied 1 year ago.
Don't know???
Expert:  JohnF2015 replied 1 year ago.
Smart Spark is an additional module that Kohler used for a while to control the ignition system. It is wired into the electrical system and controls the spark from the ignition coils. It is a box about 2 1/2" X 3" mounted on the outside of the sheet metal cylinder covers normally on the starter side of the engine.
Expert:  JohnF2015 replied 1 year ago.
Can you provide the Spec number from your engine for me?
Customer: replied 1 year ago.
CV740 - 0021
Expert:  JohnF2015 replied 1 year ago.
Okay. According to the parts diagrams for your model and spec you do have the smart spark control module. I am going to tell you that the smart spark module is most likely bad which will cause similar problems with both ignition coils because it controls both of them. I would suggest removing the smart spark module and have it tested or checked by an authorized Kohler service center or your local repair shop. The key here is that they will have to have the Kohler tester to do this. If in fact the smart spark module is bad you will have to retrofit your engine with two new style ignition coils which will do away with the smart spark module, you are looking at a cost of approximately 85-90 dollars for the retrofit update kit. I hope that this helps you it has been a pleasure serving you today. Thanks
Expert:  JohnF2015 replied 1 year ago.
The Kohler part number you will need is 25 707 03-S, this will be a retrofit update kit which should solve your problem.
Expert:  JohnF2015 replied 1 year ago.
I hope that I have been able to help you today and answer your question. Thank You it has been a pleasure to work with you.
Customer: replied 1 year ago.
Thanks. I will check it out.
Expert:  JohnF2015 replied 1 year ago.
You are very welcome. Thank You