425 Garden Tractor Won't Start

BCWoodtick · Sep 2, 2015

Hey guys, I have a 425 Garden Tractor and have been having intermittent troubles with it starting. It appears to loose spark and after researching and screwing around with it I think it is the Delay Module.... Will be putting a new one in and hoping it will solve the problem?? Wanted to get this thread going has have seen this solution on other places on the net. Will update soon let you know if it works... AM 128906 is the part number if anyone has the same tractor.

davesl708 · Sep 2, 2015

Hope that solves your problem.

Leejohn · Sep 2, 2015

What does the Delay Module do and what is it for?

BCWoodtick · Sep 2, 2015

Honestly I'm not totally sure what it does? I think it helps the firing of the spark plugs... I changed it and it started right away... so if anyone has any problems with 425 starting and has fuel going into carb but spark not hitting plugs definitely try this fix... here in Canada it was 40bucks. 10min job to switch over as well...

Leejohn · Sep 4, 2015

Sure never heard of that before. Sure would like to know more about it. What engine is JD useing in the mower?

BCWoodtick · Sep 4, 2015

Off the top of my head believe it 20hp kawasaki engine.

beenthere · Sep 5, 2015

What is the s/n of your 425? There are some s/n breaks and changes in the fuel supply, I believe.

It is the Kawasaki engine in the 425's.

I understand the time-delay module is for keeping the engine from shutting down if bouncing on the seat and causing a disconnect. The delay module keeps the engine from shutting down immediately as well as letting some fuel burn off so not to get a backfire.

What I am wondering, is if your 425 problem might be related to the fuel pressure monitoring system that consists of the several vacuum hoses connected to the carburetor.
But have not been able to understand just what the problem is or why determined to replace the time-delay module. Hope that works for starting.

BCWoodtick · Sep 5, 2015

The 425 would start one day then go to start it the next day or hour and wouldn't start... fuel was getting into carb and seemed like the spark plugs weren't firing so not getting spark? I would mess around with it, pull air cleaner off, pull plugs out, and really not do anything different and then it would start again?.. Very frustrating...
I did a search on Web and found that lots of people had found by changing the delay module it would fire right up... Well it did and seems to be fine now... from your description sounds like it keeps the engine firing so maybe a fault in the module is what was causing it, and intermittent at that.
I'm far from a mechanic so very happy it was an easy fix.
I didn't find any info on this site about it so figured I should share.
It seems to be getting info on the 425 is getting tougher and unfortunately it is getting older so any info on this model is always appreciated.

beenthere · Sep 5, 2015

Great to hear that you have it fixed.
I missed that line in previous post that you had already changed it out and that you are up and running now.

:thumbsup:

texasranger556 · Sep 6, 2015

beenthere said:
What is the s/n of your 425? There are some s/n breaks and changes in the fuel supply, I believe.

It is the Kawasaki engine in the 425's.

I understand the time-delay module is for keeping the engine from shutting down if bouncing on the seat and causing a disconnect. The delay module keeps the engine from shutting down immediately as well as letting some fuel burn off so not to get a backfire.

What I am wondering, is if your 425 problem might be related to the fuel pressure monitoring system that consists of the several vacuum hoses connected to the carburetor.
But have not been able to understand just what the problem is or why determined to replace the time-delay module. Hope that works for starting.

I agree, the 425 takes a few seconds to stop running after you hit the key. I believe there is a fuel shutoff that closes immediately but the spark continues for a few seconds afterward to avoid a backfire like you say. It also has the effect of keeping the engine going if your butt comes off the seat for a second or two. If memory serves (and the last time I drove a 425 was many beers ago), the PTO shuts off if you bounce off the seat but the engine keeps going for a short period.

From an electrical standpoint, I don't think the delay module is much more than a few caps with bleed-down resistors that takes a few seconds to drop the voltage to the coils. It could have some sort of timing circuit I suppose, will have to open one up if I ever run across one again.

Woodtick-glad you got your tractor going. Hopefully you already have them metal cam gear installed, I've replaced several of the plastic ones. Hope somebody got chewed out for that design!