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View Full Version : Kawasaki FC 420 Ignition problem


summej
07-12-2007, 08:49 PM
Hello,

I have been reading through some of the old threads here and have found some helpful info. My 14 hp kawasaki will run fine cold with a new spark plug in it but as soon as I shut it down it will not start back up. I have replaced the air filter, fuel filter and sparkplug . I am on my 4th plug and at a loss as to what the problem is. I have check the spark when this problem occurs and it is weak at best. I am thinking either igniter, coil or magneto??

Any help would be appreciated.

Jim

Restrorob
07-12-2007, 09:45 PM
I don't guess you stumbled across this, Perform the below test to determine which may be at fault.

The magneto will not apply to this problem.


http://i107.photobucket.com/albums/m314/Restrorob/FC540IgnitionTest.jpg

kcarl
07-17-2007, 12:19 PM
I'm having a similar problem with my FB460V. I get a very small, blue spark that won't jump more than 1/16" using the plug wire and a screwdriver against to ground. I cleaned the flywheel and coil, and checked the air gap, disconnected the "kill" wire, all with no change in spark.

The coil secondary measures 18k ohms and primary less than 1 ohm. The trigger (control module) measures 1.3k ohms with meter leads in either direction.

Any suggestions?

Thanks,
kcarl

Restrorob
07-17-2007, 07:51 PM
Check the coil and control unit per the test chart below to make sure you are testing properly.



http://i107.photobucket.com/albums/m314/Restrorob/Kawasaki/FB/FB460CompleteIgn.Test.jpg

kcarl
07-17-2007, 09:17 PM
Thanks, I used those diagrams from an earlier post you had replied to and got the results shown in my previous post. I triple checked the way I was taking measurements. I also applied voltage to the trigger module with a current limiting power supply and got it to switch on and off at around 11 VDC, so I think it's ok (I ran this test with the trigger off the mower). I changed the plug and checked the coil air gap.

With the coil installed and ground wire disconnected at coil (including trigger wire) should I see any deflection on a meter at the secondary or primary windings when the engine is cranked?

Thanks,
kcarl

Restrorob
07-17-2007, 10:38 PM
I don't know about any deflection, I never went that far. I always find one of the two coil/control unit bad and just replaced the bad one.

You may want to go back to the control unit, You are not supposed to be getting 1.3 in both directions.

kcarl
08-02-2007, 07:18 AM
Just to follow-up, I replaced the trigger and the mower runs fine now. I would also like to mention that the new trigger reads ~3k ohms in both directions, so the spec sheet provided above applies only to the OEM part listed. Thanks for the help Restrorob!