430 Grill

Is it missing the retaining clips on either side at the bottom where it engages the side panels?? And is it in the correct position above the hood hinges mounting panel? Something isn't right or it would not do this! Mine never has.....

I mowed an acre, it began to lose power as I was finishing the area. I ran it up on the cleanout stand, washed the underside of the deck, like I always do, tried to start it to put it away, no start. Hearing the fuel pump running, I turned it off, opened the hydrostatic relief valve and towed it to the shop with the wife's GX345 and began the diagnosis.

No spark, checked fuses, power to the coil, checked the plugs, etc. I pawed through the "425 Parts" box, found an old ignitor and an old delay module. Not wanting to waste a lot of time, I did something I've warned others about for many years. I replaced both components before checking for spark again. Not good, what now!

I put the original ignitor back on, still no spark, put the used replacement ignitor back on, took the replacement delay module off, put the original module back on, now it starts & runs good! Long story made short, two defective components, one in the spare parts box and one on the tractor, swap them going back & forth at the same time and the result is the same, no spark.

Lesson in all of this....if you're going to stand back and "shotgun parts", just replace one part at a time, if it doesn't provide the desired results, throw another one at it, repeat as necessary..


I would never purchase new parts while using this method, but...with a box full of used junk, sometimes it works...

........and another useless tidbit of information........!

I found out, the hard way, that the newer style of Bosch plugs have a shorter wire connection end than the NGK plugs that I took out of the 425 recently.

This presents a problem. I had installed an old Hotrod style of Rajah(tm) clip on the coil plug wires some years ago because the old boots became brittle and had broken. They provide a positive snap-on connection, can be easily tested for spark with the engine running, and they look kinda cool too. The problem was, the Rajah clip needed a longer attachment point on the spark plug, to make full contact with the spring clips.

After a plug wire (both sides) fell off several times, I found the problem, replaced the Bosch plugs with the original style of NGK's. Problem solved, plug wires don't vibrate off anymore.

This may have contributed to the original ignitor failure, running a coil open circuit can cause voltage spikes, not sure if it could damage any parts, but it can (and has done so) on a modern automotive ignition system.