My Tractor Forum banner
  • Are you passionate about Tractors? Would you like to write about topics that interest you and get paid for it? Read all about it here!
1 - 20 of 26 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter · #1 ·
Hi All,

I need some help diagnosing an issue. This is on an LX255 JD Tractor. Here is he tractor details if it helps:

Tractor Data

The motor is a 15HP Kohler 426cc 1-cyl gasoline.

We had an unfortunate fire under the engine. I think it was just caused by a build up of leaves and other debris and was possibly ignited by the engine heat and/or exhaust. In any event, my wife was operating the mower at the time. She shut it off (and did not stall if that matters at all) and got away. The fire burned for about 60 seconds before I was able to get to it with an extinguisher and put out the flame.

I’m trying to assess whether it is worth trying to salvage the mower. It has run great. My Father owned it first and gave it to me. It is about 20 years old and has been perfectly reliable, so I am willing to put in a bit of work if it’s salvageable. Here is what I’ve done so far.

  • I checked the oil and it looks fine. It did not burn off.
  • The motor turns when I turn the key, but it does not fire or even try to start.
  • I checked the spark with a plug tester and I am getting continuous spark when cranking.
  • I changed the fuel filter
  • I’m taken off the fuel lines at several places up to the carburetor and fuel flows from each when cranking. It’s a slow trickle but it’s feeding fuel.

Before I start taking apart the carb, I’d like to understand what the above is telling me. There is a significant amount of fire damage to the wires on the right side (looking at it from behind) of the engine. If the engine wasn’t cranking and I wasn’t seeing a spark, I would have suspected that the safety wiring from the seat and/or from the foot brake was faulty and keeping it from starting, but as I stated this is not the case. So my first question:

Does the cranking and spark indicate that this non-starting issue is not related to the safety wiring form the seat and foot brake (or maybe it’s a clutch, I always called it a foot brake, but I mean the pedal you need to depress to start the mower)?

I’ll start there and if confirmed I will replace all of the fuel lines and dig into the carb. Is there anything else that I can do before disassembling and cleaning the carb to test other components. I’m not afraid of carb cleaning, I do it all the time, but I’d rather eliminate all other possibilities in front of the carb if possible. Given the fire, what other plastic or rubber components should I be looking at as a possible culprit?

If I can salvage this motor, I will post a different thread troubleshooting why the fire started in the first place....

Thanks in advance,
Rob
 

·
Registered
JD317, JD318, JD430GT
Joined
·
516 Posts
If you are able to crank and getting spark, then I think you've made all the safeties to run (although it is possible that the fire shorted a safety - so once running, confirm that the safeties work properly). Does your carb have a cutoff solenoid on it (it would have a wire going to it)? If so, you may not be getting any gas if that wire is bad.

If you spray starting fluid or pour a few drops of gas into the carb before you crank it, will it try to start? If so, you definitely have a fuel supply/carb issue
 

·
Registered
Joined
·
1,104 Posts
Some pictures would be really helpful in helping assess the damage.
 
  • Like
Reactions: rmcderm313

·
Registered
Joined
·
14 Posts
Discussion Starter · #4 ·
Thanks. I was just researching the cutoff solenoid. Yes I do have one. I'll trace that wire and see if it's damaged. Is there a simple way to jump that wire, like straight to the battery to force the solenoid open. I'll try dripping some gas into the carb and see if it tries to start as well. And I will definitely test all safety features and get them working again if necessary once I get this to start.

Thanks for your input.
Rob
 

·
Registered
Joined
·
2,465 Posts
60 seconds of burning leaf debris shouldn't produce enough heat to do any engine damage other than wiring.

"CantKeepUp" had a good idea, check that fuel bowl solenoid and its wire if so equipped. Chances are a fire from below may have burnt that wire off or allowed it to ground out.
 
  • Like
Reactions: rmcderm313

·
Registered
Joined
·
14 Posts
Discussion Starter · #8 ·
I was surprised given the damage to the area where the foot brake 'safety' wire traverses, I was expecting it not to turn over at all. But since it is turning over I'm speculating this wire is still intact. I'm guessing the fuel shut off solenoid as that wire is severely damaged. Tomorrow I'll jumper that wire to the harness connector it goes to and see if that does the trick. Am I correct in remembering that if you try and start the mower without being in the seat and/or without having the foot brake depressed, that it doesn't crank at all? Right now it is allowing the motor to crank even when I'm off the mower. Can someone verify the expected behavior in that regard.

Thanks for all the help so far, I'm definitely moving in the right direction.
Rob
 

·
Registered
Joined
·
2,465 Posts
I'd start with being sure the fuel solenoid wire (red circled) has power to the solenoid when the machine is in operational mode. If not, that solenoid will not allow fuel to pass into the jets. The solenoid should "click" when the ignition key is turned on.
2456669
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #10 ·
I'd start with being sure the fuel solenoid wire (red circled) has power to the solenoid when the machine is in operational mode. If not, that solenoid will not allow fuel to pass into the jets. The solenoid should "click" when the ignition key is turned on.
View attachment 2456669
Thanks. Would that just be +12v when the key is turned? What do you consider 'operational mode'?
Rob
 

·
Registered
Joined
·
1,104 Posts
Thanks. Would that just be +12v when the key is turned? What do you consider 'operational mode'?
Rob
Correct, it should get +12v.

Note that you also appear to have a crispy ground wire running from the carb to the block - that also needs to be intact.
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #12 ·
The fuel shut-off solenoid is clicking when the key is turned and I'm getting +12v. Can I assume that if I'm getting +12v that the ground wire is doing it's job even if it's damaged? Spark, some gas getting through (maybe not enough but I'd think it would be enough to make it try and start), solenoid seems to be working. I can't think of anything else except just a clogged carb, so I'm going to try that next. I can see a bunch of crud through the air filter holder, so I'm guessing something got into the carb and is gunning things up. Thanks again for the help so far. Any other troubleshooting thoughts in the meantime would be appreciated. Probably won't get to the carb until later in the week.
Thanks,
Rob
 

·
Registered
Joined
·
1,104 Posts
Sounds like the carb is your next step but before taking it apart, I would make sure the engine will start momentarily with a little gas down the air intake.

Assuming it does, I would pull the float bowl, float and need, and crank the engine to flush out any debris, I would then pull the hose and blow air or carb cleaner back through the inlet valve. Then put it back together and try again. If that fails...then I'd pull the carb and do a complete cleaning.
 

·
Registered
JD317, JD318, JD430GT
Joined
·
516 Posts
Looking at the black on top of the carb and the knowing the heat that was on the bottom of the carb and the solenoid, I think I'd be pulling the carb just to give it a good soak down and cleaning.

Even though the solenoid clicks, if it saw enough heat, it might be internally damaged.
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #17 ·
And you probably want to get that extinguisher residue cleaned off as soon as you can too. The dry chemical can be fairly corrosive stuff.
Any recommendations on cleaning off the engine? Should I just wipe it down, or is a degreaser and rinse better?
Thanks,
Rob
 

·
Premium Member
Joined
·
234 Posts
It may take more than just hose pressure, that powder tends to stick on like burned eggs.... The degreaser will help where it is stuck to any sticky spots. Try the rinse and go from there, but it may in fact need a pressure washer.
 
1 - 20 of 26 Posts
Top