Kawasaki FD731V AS09 ignition/coils testing question

[txmowman]

That engine probably it is mounted on a JD mower. Kawasaki USA is barred from allowing you look it up.

Now here's a twist it uses two different coils (one of Each)

View attachment 70696

FD731VAS09 was actually on Bad Boy mowers

 

[Hardluck]

They can be but not for the reason most people would think. Here's my experience with mine.

Kawasaki coils use carbon track plug wires, simply a string that is carbon dust impregnated in the sheath. My engine would run rough at times and then one day one cylinder just stopped firing. Coil tested good but there was zero connectivity thru the cable. Removed the plug rubber cap and saw that they used a crimped over connector with prongs that penetrated the sheath to make contact with the string. Except when I looked closely there was no string visible at the end of the sheath. Cut it back past the crimped prong points and there was the carbon string. Now I could measure connectivity. Got a pair of these and everything started working again. These have a wood screw type thread that runs up into the sheath center core and makes much better contact than the Kaw setup. Not saying this is your problem but just something to check and a solution if it is.

View attachment 70695

Thank you

 

[bentrim]

There may be an Igniter used on this engine according to the service manual. Best to check them before condeming the coils. If it is on a John Deere the also have a control box that will kill the spark. Ask me how I know that one gave me a fit.
I attempted to attach the service manual -- but too large. I attempted to copy & paste but that did not work either.
If someone can tell me how I can uplad the service manual, it is a pdf.

 

[txmowman]

There may be an Igniter used on this engine according to the service manual. Best to check them before condeming the coils. If it is on a John Deere the also have a control box that will kill the spark. Ask me how I know that one gave me a fit.
I attempted to attach the service manual -- but too large. I attempted to copy & paste but that did not work either.
If someone can tell me how I can uplad the service manual, it is a pdf.

No igniter.

 

[StarTech]

Kawasaki FD680V, FD731V Service Manual

 

[Skippydiesel]

Try this;

https://www.kawasaki-engines.eu/en/support/technical-information/technical-downloads/?f_series=FD&f_model=FD731V

 

[RevB]

Can a coil fail? Sure. It is common for both coils to fail, not likely. That is why I suggested removing the ground wire from both coils to see if either has spark.

Yes...there are two transistors in each coil and they can and do fail. Every revolution of the engine creates a spark. At 3300RPM that's 55 sparks a second. The high heat environment doesn't bode well for long life.

 

[RevB]

That engine probably it is mounted on a JD mower. Kawasaki USA is barred from allowing you look it up.

Now here's a twist it uses two different coils (one of Each)

View attachment 70696

Just replaced both of mine at 480 hours on the originals. The result was dramatic.

 

[Hardluck]

Thank you for the replies. I looked up the link thanks, got some part numbers. I am still looking for how to adjust the carburetor? The advice was to adjust the carb if you had poor high rpm performance issues. But it doesn't what to set the screws at?

I can get it to start and run, and run pretty well until I start the mow , load the engine. It restarts well but will hardly pull itself up am incline with the pto on.
The coils have good spark but I am guess I am at the point that I will replace the coils since I have tried everything else. Except getting the carb adjusted correctly. The carb is very difficult to adjust when you are trying to run the mower / pto. My arms aren't long enough! LOL with the rear mounted engine on the Badboy mower!

Thanks again for any and all suggestions.

 

[bentrim]

May be a dumb question but do both cylinders have compression? I have seen twin engines come in on running on one cylinder. One rod was broken. But it "just needs a tuneup, it is low on power".
Do you have an inline spark tester? The one that looks like a troubleshooting current tester? Install between the ignition wire and spark plug, go attempt to mow and see iof the spark drops out.

https://www.harborfreight.com/in-line-spark-checker-63590.html?gQT=1