Kawasaki FD440V on JD LX178 dies after a few minutes runtime

I pulled the John Deere out of the garage for spring mowing season. Replaced spark plugs, cleaned carb and fired up GOOD. Mowed several times with at least 3 hours total runtime. The mower was smooth and powerful. I tried to mow a few days later. Ran good for approx 30 minutes. Then began surge, cough and eventually died. Let it sit for 5-10 minutes and it would start good but only run for a few minutes before it would die again. I put it away for a week. Pulled it out and it starts quick and easy, but only runs for a few minutes before symptoms return and the mower dies. I spoke to a mechanic and he said it sounds like ignition coil. Any other opinions would be greatly appreciated.

 

Just for a goof, Try it with the gas cap loose.. Maybe the vent is plugged?? Roger

 

My first instinct was ignition coil as well, but by all means - try the cheap stuff (like the gas cap) first!

 

gas cap first, then coil. When it does die, immediately check for spark.

 

i agree with hopkinsr2, that may be the problem.

do you have a multi meter to test spark while driving?

you should also replace the oil as you are supposed to every year, depending on use, have you?

 

I think the gas cap and coil are two likely culprits.

You won't be able to test for spark with a multi-meter, and fresh oil won't have any effect on this problem unfortunately, just be sure the oil is full.

 

yes i know that the oil wont effect it, but he was replacing spark plugs and such, its a good idea to replace to start the season.

my multi meter works great for checking spark...

 

A multimeter, when properly configured will tell you:
1. If there is a potential difference between the plug wire and ground
2. How much that potential difference is.

This will be difficult to do with all but the most sophisticated digital multi-meters. Might be possible to do with an analog meter, but I've never tried it. Regardless, it won't tell you if an actual spark is occurring, just if the right conditions exist for a spark to occur. Those conditions, of course, are application dependent.

All that aside, most meters are only rated for a few thousand volts anyway. Ignition systems usually operate in the 10s of thousands of volts. Personally, I wouldn't risk damaging/destroying a meter for a simple spark test. Much easier to either use a spark tester (the right tool for the job) or a known-good spark plug. Just my $0.02.

- Joe

 

bluethunder, how do you check for spark with your multimeter? You can't measure a 25,000 to 60,000 volt arc from a spark plug with a simple multimeter.