My JD D125 wiring woes

Howdy Guys,

I am still having issues with my JD D125, I got it rewired using the diagram for the B&S engines from the wiring diagram thread, but it still will not crank, I get it to spin over but it won't run. I uploaded two videos to my youtube channel showing how I got it wired up and I am hoping I can get some ideas on where I messed up, I apologize for the video quality (shaky, apparently). Thanks in advance!

youtube.com/watch?v=8Djw3Xvc-0g  This is the wiring rundown and attempt to crank.

youtube.com/watch?v=3rhbwVat5Sg  This is where it actually ran for like two seconds but was low RPM and quickly shut off.

I can't post links yet so ya'll will have to copy and paste, sorry!

Inserted jimtolken's videos here for ease for everyone..





Are you posting from a mobile device or computer?  If computer for youtube vids, just hit the youtube icon in the formatting bar and paste your URL in the popup and click insert.  It will reduce it down to a quicklink.

Thank you MightyRaze!

I think your problem maybe your coil kills being tied together?

Also, your starter seems to be wiggling a lot? Possibly your starter ground issue?


Check out Doc's Video.

OMG, I am an idiot, LOL, I am going to fix this today and i'll let ya'll know how it goes.

Thank you mightyraze and thank you doc sprocket!

I did an update to my previous post.  Make sure your starter is tightened down good, it seems to be wiggling.  This could cause some of your starter ground issues.

Hope that works out!!!

The starter is a bit loose, I tried tightening the left side and I think I stripped it inside the block, i'll try tightening it some more maybe it isn't stripped.

It is stripped, little aluminum shavings came out of it when I backed it out to retighten.

Here it is "running" if you could call it that, keeps shutting off and real low idle.

Sounds like its either carb related or its running on one cylinder. Could be a bad coil on one side. Sometimes the head(s) can warp slightly and cause loss of compression, but usually that only happens if it runs really hot. That could happen on either cylinder, not necessarily both. Have the cooling fins been kept clean?

I got it figured out, I forgot to put the spark plug boots on the new wires and it was trying to run on one cylinder (partially), got the boots put on and voila I got vroom!

I also cleaned the ports on the carb even though it looked brand new inside.

What CraftsmanQuad19 said...

other items to consider. (for sanity sake, one at a time) LOL
also you said you cliped the fuel shutoff. Is it cut enough to not interfere with the float?
Unplug your fuel pump line to the carb, is it pumping gas?

If not,
Here is one that I did, after cranking so much could you be running out of gas?
Unscrew gas cap and try again (could be plugged)

a few more things to check..

jimtolken wrote:

I got it figured out, I forgot to put the spark plug boots on the new wires and it was trying to run on one cylinder (partially), got the boots put on and voila I got vroom!

I also cleaned the ports on the carb even though it looked brand new inside.

Scratch my other post! EXCELLENT!

I put fresh gas in the tank (it was low), when I cleaned the carb I made sure the fuel solenoid was completely out of the way of the intake port, the pump is working (runs off vacuum from valve cover). I will be getting better wire to use for the new "wiring harness", I just used what I had from gutting the old wiring to get it to run.

All of ya'lls help has been greatly appreciated since this is also what I cut my grass with and spring is coming!

Glad we were able to help out! Had some arcing there in the end eh!

Quick fix at that. I've seen a thread like this one in one of the other forums I frequent go for days. Then again, it helps when the owner has an idea of what is going on as well!! Good Job!

I actually have been working on this mower for a couple of weeks, only had the real time to mess with it this week.