D125 Coil problem?

[aussietrev]

Hi all.
I have a D125 with the 20HP V Twin and it intermittently will only run on one cylinder but then suddenly the other one kicks back in. It might run fine then for a couple of hours or it might play up again within minutes. I'm thinking probably a coil pack, I replaced the plugs even though they both looked okay, and am wondering if there is an aftermarket coil pack available since they want $150 for a genuine one here in OZ. If there is, can anyone tell me the part number please. Anything else that could cause this symptom? The machine has done just over 600 hours.

 

[bertsmobile1]

Start with the easy bits first
Remove the rocker covers & check the valve lash .
NExt , confirm that the fuel solenoid on the carburettor is working, it should click on & off with the ignition switch.
If so then remove the top cover and remove the kill wires from the coils
Run the mower like this and see if the problem goes away , The kill wire has 2 diodes in it that fail causing random ignition problems
Remember that the mower is more dangerous to use in this condition so it is just for testing , not a cheap fix .
Get back with the results
You should have a Briggs & Stratton 40 series (40?877–0008–G1) which uses the #691060 B & S magneto
Genuine B & S from a JD dealer will be the cheaper than from a B & S dealer by 20% to 30% as JD parts are not subject to the Melbourne Mower Parts Mafia prices
JD part no # MIA12788
The Stens part is # 440-445 which I can do for $ 60 + P&P if you are interested
Do not even think of getting one from Scamazon or Evilpay as the bulk of what is on there are defective parts bought as scrap metal then sold to people who are too cheap for their own good .

​

 

[Tiger Small Engine]

Start with the easy bits first
Remove the rocker covers & check the valve lash .
NExt , confirm that the fuel solenoid on the carburettor is working, it should click on & off with the ignition switch.
If so then remove the top cover and remove the kill wires from the coils
Run the mower like this and see if the problem goes away , The kill wire has 2 diodes in it that fail causing random ignition problems
Remember that the mower is more dangerous to use in this condition so it is just for testing , not a cheap fix .
Get back with the results
You should have a Briggs & Stratton 40 series (40?877–0008–G1) which uses the #691060 B & S magneto
Genuine B & S from a JD dealer will be the cheaper than from a B & S dealer by 20% to 30% as JD parts are not subject to the Melbourne Mower Parts Mafia prices
JD part no # MIA12788
The Stens part is # 440-445 which I can do for $ 60 + P&P if you are interested
Do not even think of getting one from Scamazon or Evilpay as the bulk of what is on there are defective parts bought as scrap metal then sold to people who are too cheap for their own good .

​

Bertsmobile-
Do you just happen to know this particular engine has two diodes in wiring from memory? Just wondering because I see very few mowers or equipment that use diodes.

 

[bertsmobile1]

The main engine harness # 591392
Google it and you will see the 2 diodes to prevent the coils sending ripples down the kill wires
Honda & Kohler have them inside the magnetos , B & S have them in the wire
I bought a 100 pack from Mouser for about 10¢ each and replace them because down here a loom is just short of $ 100 US
I make up a new set of kill wires then splice it into the old loom as B & S usually crimp them into the wires & there is not enough space to solder a replacement and if the wire breaks then the kill is non functional .

 

[StarTech]

And you use both splice crimps and heat shrink tubing. Of course I usually replace all the terminals when I make up a new harness. They are not that expensive but the tool is for for use on one project only. When I brought the open barrel I thought $70 was high but have since brought a second one as I had have one of the supplied dies modified and I would definitely buy again if needed.

Splices are Mouser PM 571-42778-2 (22-15ga). These are also use for installing thermal fuses. There is a couple larger sizes available too. These also allow splicing a lead off the main line ie a Y connection without cutting the main line.

 

[bertsmobile1]

We are getting a bit ahead of ourselves, lets wait for Aussietrev to come back with the test results

 

[aussietrev]

Sorry haven't gotten to pulling it down yet, it has been horrendously hot here in Oz and not conducive to being in a shed with no AC Will report on findings once the weather changes for the cooler.

 

[StarTech]

I trade 50% of you heat for 50% of my cold days lately. That way we both be halfway comfortable. Not laying the cold asphalt in 20-30F temps with the wind blowing just to do electrical wiring.

And the summer months I am a shade tree mechanic for a reason; otherwords, I am not stupid enough to work on 140F asphalt on those days. I rather cook my steaks at 140F+ temps.

 

[bertsmobile1]

I go native at this time of year
Nov & Dec it is dawn & dusk so siestas in the woods from 12 till 8pm
then from Jan to March it is nite shift for work & sleep during the heat of the day
Was 42 C yesterday, will be 45 today & around the same all next week .

 

[StarTech]

Please Bert I didn't want that thought in my head this early in the morning. That would be as bad as the Shawn pants that were posted on the ODK forum a few years ago,