JD300 Backhoe Loader Spark Plug Overheating

[Jaucet]

I been having issues with my JD300 starting up fine, but then stopping after like 10 minutes of working. So far I have:

Change the engine oil, hydraulic oil, fuel pump, the spark plugs, spark plug wires, and starter.

I found a symptom I didn't know about. When I remove the spark plugs initially, the first chamber spark plug was not gapped at all, and the wire was hard and corroding. That's why I changed out the plugs, gapped it right, and got new wired for them. Today, started out strong, but about 10 minutes into it, stopped again. But I noticed there was white smoke coming out of the spark plug hole and the wire was melting on to it again.

What could cause this?[/code]

 

[RandyC]

White smoke coming out the spark plug hole ?
Was the plug loose ? So before this was everything fine ?

 

[Jaucet]

No everything wasn't fine, I been trying to figure out what the issue was, but nothings been working. I thought I figured it out with the bad plugs and wires so I changed them out, but seems like this new spark plug is doing the same as the old one by overheating. I will try and tighten it more tomorrow. Thank you!

(quoted from post at 20:12:29 10/13/23) White smoke coming out the spark plug hole ?
Was the plug loose ? So before this was everything fine ?

 

[Jim.ME]

Welcome to the forums.

We understand everything is not fine. Randy was trying to get some history of the problem. People reading your post don't know if you just got the tractor, with this issue, or have had it for a time and this issue just developed. Neither can anyone here see what you are seeing, so accurate descriptions are needed. Here are more questions that may help get to the bottom of the issue.

Do you have the manuals for it? JD300 uses their OMT24467 Operator's Manual and the SM2073 Service Manual.

Is the tractor new to you and it had this issue since you got it? Or have you had it for years and this issue developed recently?

Had it been setting (not running) for an extended time prior to either you acquiring it or running it this time?

Was it setting outside? Vertical exhaust? If vertical was the stack covered or uncovered?

You posted the first plug was not gapped at all. Does that mean the side electrode was bent tight onto the center electrode (metal to metal contact)? Or was the area between the two electrodes built up with carbon so the gap was not visible?

I don't understand the white smoke from #1 cylinder. If a good sparkplug is properly tightened in the head nothing should be escaping from the cylinder. Was the plug in when you saw the smoke? Or is the white smoke coming from a burning wire, based on your comment of the wire melting?

Is the radiator coolant level staying consistent or is it loosing coolant? Does it blow coolant out the overflow?

Does the temperature gauge work? What does it read when you are operating the machine?

What color is the engine oil?

Have you done a compression test?

 

[Jaucet]

Hi Jim,

Sorry for the lack of details, I was out yesterday while posting so couldn't go into details


Do you have the manuals for it? JD300 uses their OMT24467 Operator's Manual and the SM2073 Service Manual.

Yes I was lucky to have the manual come with the backhoe when I bought it like 4 months ago.

Is the tractor new to you and it had this issue since you got it? Or have you had it for years and this issue developed recently?

I got the tractor 4 months ago. He told me everything works fine but it overheats after using it for a while, and to let to cool back down to use it again. It would turn on fine while cold, work for 30 minutes, then it would power down. I did the due diligence in changing the motor oil, the filter. Changed the coolant. When I opened the hydrualic dip stick, all this milky white fluid came pouring out through the dip stick hole. I drained all the hydrualic oil, changed the filter, and refilled with like 15 gallons of the right hydraulic oil. Still about the same issues. I thought it might be the oil pressure since it would start fine but start power down when hot. So I tried changing the oil to a thicker SAE40, but that made it hard to start it. I drained that and went back to SAE30. That was better. It "powers down" as it it stays on normally and I can Rev the engine all I want but when I put a load on the hydraulic I can hear the engine start to stall and I just need to wait a few seconds for it to sound stronger again and continue or just move very slowly. At some point, my batteries died, I recharged it. Then my starter died as I was cranking it a lot since when it heats up and turns off, it doesn't start again easily . I changed the starter to a new one but it was a little thicker so it wasn't making the oil fuel pump fit right so I replace the fuel pump with a new one too.

Then it didn't start at all, so I looked into the spark plugs since I figured they were old. When I took them out, the first chamber (closest ti the seat of the tractor) there wasn't a gap at all. I was like great, I found the problem. So I bought new plugs, the line to the first spark plug was hard and breaking so I changed the 4 wires out to new ones. Still it would crank slowly so even after trying to charge the batteries for a few days, I figured the batteries at old.

I bought new batteries to replace the batteries, but before changing it out, I just wanted to try one more time..and of course it started up. It sounded and worked strong for 10 minutes, backhoe and loader, as long as I went slowly, and then power down again when I put a load on it with the backhoe after like 10 minutes. I still had the cover off since installing the wires and plugs, and I noticed a lot of smoke coming from the first sparkplug. I gapped them before putting them in. I pulled the wire off and some of the rubber had already melted onto it

Had it been setting (not running) for an extended time prior to either you acquiring it or running it this time?

It was running and the guy said be bought it, used it to build his house, put a few fuel tank on it, and then sold it to me. I been working on it since then

Was it setting outside? Vertical exhaust? If vertical was the stack covered or uncovered? It is stilling outside. It is vertical and it is covered

You posted the first plug was not gapped at all. Does that mean the side electrode was bent tight onto the center electrode (metal to metal contact)? Or was the area between the two electrodes built up with carbon so the gap was not visible?

It was touching metal to metal

I don't understand the white smoke from #1 cylinder. If a good sparkplug is properly tightened in the head nothing should be escaping from the cylinder. Was the plug in when you saw the smoke? Or is the white smoke coming from a burning wire, based on your comment of the wire melting?

It at first looked liked it was from the cylinder but seeing the rubber melted onto the plug, when I pulled the wire it would seem as though it was from the melted wire, NOT chamber

Is the radiator coolant level staying consistent or is it loosing coolant? Does it blow coolant out the overflow? Before changing out the coolant when it overheated, some coolant would blow out the top. The cap was broken. But I changed the coolant and now it stays consistent and doesn't spew out the top. I also replaced the cap for the radiator and the fuel tank since they were old

Does the temperature gauge work? What does it read when you are operating the machine?

Unfortunately the temperature gauge and the tachometer do not work. The fuel one moves but I don't think it's accurate

What color is the engine oil?

It was a little milky when I first changed it out. Now it's clearish yellow?

Have you done a compression test? I have not, I'm not sure how to

If you have any other questions please ask me. Thank you all so much for your help. I would really like to finish my underground greenhouse before it gets colder

(quoted from post at 04:44:08 10/14/23)
Welcome to the forums.

We understand everything is not fine. Randy was trying to get some history of the problem. People reading your post don't know if you just got the tractor, with this issue, or have had it for a time and this issue just developed. Neither can anyone here see what you are seeing, so accurate descriptions are needed. Here are more questions that may help get to the bottom of the issue.

Do you have the manuals for it? JD300 uses their OMT24467 Operator's Manual and the SM2073 Service Manual.

Is the tractor new to you and it had this issue since you got it? Or have you had it for years and this issue developed recently?

Had it been setting (not running) for an extended time prior to either you acquiring it or running it this time?

Was it setting outside? Vertical exhaust? If vertical was the stack covered or uncovered?

You posted the first plug was not gapped at all. Does that mean the side electrode was bent tight onto the center electrode (metal to metal contact)? Or was the area between the two electrodes built up with carbon so the gap was not visible?

I don't understand the white smoke from #1 cylinder. If a good sparkplug is properly tightened in the head nothing should be escaping from the cylinder. Was the plug in when you saw the smoke? Or is the white smoke coming from a burning wire, based on your comment of the wire melting?

Is the radiator coolant level staying consistent or is it loosing coolant? Does it blow coolant out the overflow?

Does the temperature gauge work? What does it read when you are operating the machine?

What color is the engine oil?

Have you done a compression test?

 

[Jaucet]

 

[Jaucet]

I'm sorry if I sounded short in my last reply. That was not my intention at all. I was posting while at dinner and I was eager to respond to you right away. I appreciate your help!

 

[used red MN]

Hello jaucet welcome to YT! I can shed some light on
the mystery of your smoking spark plug. The previous
owner has applied a bandaid over a bigger problem.
Look closely at the part that the spark plug is screwing
into. I am seeing another hex down in there. An ..anti-
fouler.. has been placed in the spark plug hole in the
head, see linked examples. Those are a little different
than yours but it was the only example I found that
shows the smaller opening into the cylinder. So that is
one way the anti-fouler works is limiting the exposure
of the spark plug to contaminants in the cylinder like
excess oil. It also does the another thing that is
causing the problem you are mainly concerned with. It
increases the temperature the spark plug operates at
which also helps it not to foul out. When the spark plug
is threaded in the stock hole it contacts right against
the cast iron cylinder head. That contact allows the
heat from the spark plug to be transferred into the cast
iron of the cylinder head cooling the spark plug more
effectively. I am also thinking that the replacement
spark plug wire set you installed may not have been
the highest quality. True silicone spark plug boots can
take a pretty high temperature. It would be interesting
to know if the other cylinders have anti-foulers as well.
The fact that the plug is fouling with an anti-fouler
does not speak well towards the condition of the
engine, it is probably using a lot of oil. FYI, I also
believe you are referring to the back plug or the one
closest to the seat as number 1, it is in fact number 3.
When the tractor stalls does it sound uneven like
shutting off and then.. catching.. then shutting off
again? This could be a lack of fuel. Look at the link,
part 18 is the elbow that connects the fuel line to the
carburetor. There is a fine screen on the side that
screws in the carburetor. I would suggest you pull it
out and clean it. Not sure what other fuel filtration the
machine utilizes, should be something. Also while you
have that line disconnected pull the coil wire out of the
center of the distributor cap and crank the engine with
the starter a few seconds. The fuel pump should
provide pulses of fuel that contain multiple
tablespoons each. If it is all but a trickle something is
blocking the fuel between inside the tank and the fuel
pump.
Also BTW that link to the carburetor diagram will show
you all the parts diagrams for your tractor. Just click
on the ..JD 300 series tractors.. at the top right to get
to the main index.
SP example anti fouler

JD 300 online parts catalog

 

[Jim.ME]

(quoted from post at 10:39:06 10/14/23) I'm sorry if I sounded short in my last reply. That was not my intention at all. I was posting while at dinner and I was eager to respond to you right away. I appreciate your help!

No Problem with your reply, you answered questions.

You may need to change the hydraulic oil a couple times to clear the system since the cylinders, valves and lines don't drain, much if any, so changing the reservoir oil is the common fix.

A number of us run 15W/40 diesel engine oil in our equipment year-round, instead of straight weight oil. Shell Rotella T4 and Mobil Delvac are a couple good ones.

#1 cylinder is the one closest to the radiator (aka front of the engine). The cylinder closest to the seat on your tractor is #3, since a 300 industrial has a 3 cylinder, 152 cubic inch engine. And for future reference, left and right are based on setting in the seat looking forward.

Plug wires can burn if they are not fully seated to the spark plug. If there is an arc made inside the sparkplug wire boot because the spark has to jump a gap between the metal top of the plug and the metal grip for the plug, it will create heat and burn the boot. Sometimes that grip gets pushed too far back in the boot during installation and causes that. The same can happen on the distributor cap end if the fit is not fully in or loose.

There should be a 1/8'' NPT plug drain in the bottom of the carburetor bowl that is often used to test fuel flow which is to hold a pint or larger container under it and remove that plug. On your tractorit won't tell much as your tractor uses a mechanical fuel pump. And you said you replaced that fuel transfer pump. However, draining the carb bowl into a container should reveal if it has any water or dirt in the bowl.

There is a fuel filter/standpipe (item key # 25) inside the fuel tank, it could be restricted. It is a total pain to get to but the valve can be removed for cleaning without removing the tank.

Does your carb still have the solenoid (item key # 24A or 24B in the picture below) at the main jet of the bowl? If it does that could be losing power. If it loses power the spring seats the needle in the jet and will shut the fuel off (that is its intended purpose for when the key is turned off to prevent the hot engine from ''dieseling''. Test with a test light to see if it has power to it when the engine quits. They can also go bad over time. If it is an original there is a thumb screw for adjustment. You can carefully remove the thumbscrew and a spring and needle should come out behind it. Move the spring to the opposite end of the needle (do not reverse the needle) and reinstall them. Tighten the thumbscrew by hand until it stops (needle seats in the jet) then back it out 2 full turns. That mechanically overrides the solenoid. This procedure was in may be of the JD Operator's Manuals and may be in yours. Post a good picture of the carb if you are unsure.

As for the temperature gauge not working. You can check the temperature at the metal housing at the front of engine where the top radiator hose connects to the engine. Depending on the thermostat in your engine it could be 160 to 195 degrees.

Your Operator's Manual should have the hydraulic capacity of the transmission/hydraulic system. I believe it is only about 10 gallons, not 15. You should be using an oil meeting the John Deere J20C specification, such as JD HY Gard or Tractor Supply's Premium Universal Tractor Hydraulic Fluid (UTHF). There are a number of other aftermarket UTHFs meeting the J20C spec, check for that on the labels. Your manuals may refer to JD303 Special Purpose Oil, not Hy Gard. Do not use any of the fluids/oils marketed as 303. JD303 used whale oil as an ingredient. Whale oil was banned in 1974 with the Endangered Species Act, so JD went to newer formulas. The current J20C is backwards compatible to the JD303.

This should give you some more to check.

 

[Jim.ME]

used red MN,

He posted the sparkplug contacts were metal to metal, which would be more a sign of damage when installed or something hitting the side electrode, than fouling. When I blew his sparkplug picture up it looked like some remains of a plug boot on the plug. It may be there however I don't see a second hex which should be there with an anti-fouler.

 

[Jim.ME]

Jaucet,

Make sure all the hydraulic control levers are centered. A lever that is slightly opening a valve can cause starting issues and load the engine when running.

As a test when the engine is warm and you are trying to start it, rapidly rock the steering wheel side to side as you crank it and see if it cranks faster. If it does that is often a sign of a hydraulic issue.

 

[used red MN]

Jim maybe you are right, I wasted a lot of breath on
that one. If the engine is truly getting that hot that oil
all over it should be smoking. I do believe that my
comment about the quality of the spark plug boot
material is likely correct.
Edit: Another thought, a loose spark plug also runs at a higher temp.
BTW does ME stand for Maine or mechanical engineer?

This post was edited by used red MN on 10/14/2023 at 11:32 am.

 

[buickanddeere]

I am good with that except for the oil . With the intent of slowing oil migration and leaving less ash/fouling when that oil burns . A straight weight 30 or 50 SF-2 oil intended for two stroke Detroit s would be better than a high additive multi weight .

 

[Jim.ME]

(quoted from post at 14:16:08 10/14/23) Jim maybe you are right, I wasted a lot of breath on
that one. If the engine is truly getting that hot that oil
all over it should be smoking. I do believe that my
comment about the quality of the spark plug boot
material is likely correct.
Edit: Another thought, a loose spark plug also runs at a higher temp.
BTW does ME stand for Maine or mechanical engineer?

This post was edited by used red MN on 10/14/2023 at 11:32 am.

He said he changed the plugs. It may be wrong but I am thinking he tightened them.

ME for Maine

 

[Jaucet]

You are correct. There is an anti fouler on all 3 sparkplugs. I replaced 2 of them and not the third one because it was still in the engine vs the others came out with the old spark plugs. So should I take the antifoulers off and try again?

When it shuts off, it powered down. When it first starts up and is working well, if it starts powering down I can stop moving the hydraulics or put the clutch in and it will power back up again. But after about 10 to 15 minutes of use, when it starts to power down, I can stop all motion and it will still turn off.

Yes the boots weren't anything special just a set off ebay that was meant for John Deere.

I looked for that elbow screen because I saw that could be the problem and I can't find one with a screen in it. Fuel seems to get to the carburetor fine. When i remove the bottom screw, a lot of fuel does come out. I will look for the screen.

(quoted from post at 09:36:25 10/14/23) Hello jaucet welcome to YT! I can shed some light on
the mystery of your smoking spark plug. The previous
owner has applied a bandaid over a bigger problem.
Look closely at the part that the spark plug is screwing
into. I am seeing another hex down in there. An ..anti-
fouler.. has been placed in the spark plug hole in the
head, see linked examples. Those are a little different
than yours but it was the only example I found that
shows the smaller opening into the cylinder. So that is
one way the anti-fouler works is limiting the exposure
of the spark plug to contaminants in the cylinder like
excess oil. It also does the another thing that is
causing the problem you are mainly concerned with. It
increases the temperature the spark plug operates at
which also helps it not to foul out. When the spark plug
is threaded in the stock hole it contacts right against
the cast iron cylinder head. That contact allows the
heat from the spark plug to be transferred into the cast
iron of the cylinder head cooling the spark plug more
effectively. I am also thinking that the replacement
spark plug wire set you installed may not have been
the highest quality. True silicone spark plug boots can
take a pretty high temperature. It would be interesting
to know if the other cylinders have anti-foulers as well.
The fact that the plug is fouling with an anti-fouler
does not speak well towards the condition of the
engine, it is probably using a lot of oil. FYI, I also
believe you are referring to the back plug or the one
closest to the seat as number 1, it is in fact number 3.
When the tractor stalls does it sound uneven like
shutting off and then.. catching.. then shutting off
again? This could be a lack of fuel. Look at the link,
part 18 is the elbow that connects the fuel line to the
carburetor. There is a fine screen on the side that
screws in the carburetor. I would suggest you pull it
out and clean it. Not sure what other fuel filtration the
machine utilizes, should be something. Also while you
have that line disconnected pull the coil wire out of the
center of the distributor cap and crank the engine with
the starter a few seconds. The fuel pump should
provide pulses of fuel that contain multiple
tablespoons each. If it is all but a trickle something is
blocking the fuel between inside the tank and the fuel
pump.
Also BTW that link to the carburetor diagram will show
you all the parts diagrams for your tractor. Just click
on the ..JD 300 series tractors.. at the top right to get
to the main index.
SP example anti fouler

JD 300 online parts catalog

 

[Jaucet]

Yes I will change the hydraulic oil again..I figured I didn't want to spend another 150 plus on the oil until I can get a pretty good working machine.

I tried 10w/30 and it seemed to work worse. I will try 15w/40 next time. BTW this is a gas engine.

Thank you it is cylinder 3 then.

I did check the wires a few times for firm fit but I will check again tomorrow.

Yes I drained the carb bowl when I first got it, and a few times since then. At first some debris came out but now just fuel comes out.

The previous owner replaced the fuel tank with a new fuel tank so I think that part should be okay unless it is outside the fuel tank.

So there is no solenoid on the carburetor. But there is something weird, when I unscrewed that screw, it is just a pin and there is no spring in there. I'll take a picture tomorrow

I did change it with j20c rated hydraulic oil. I didn't use hyguard since it wasn't working well enough yet and I knew I had to flush it again. But I did use j20c spec oil. My manual said 15 gallons or something but only 12 ish gallons got changed

Thank you so much for the suggestions! I will check those items and update again with picture of the carb!

(reply to post at 09:40:00 10/14/23)

 

[Jaucet]

I will try the rocking back and forth and report back!

 

[Jaucet]

There is an anti fouler in all 3 spark plugs. What should i be looking for in a quality wire? Thank you

 

[Jaucet]

Im pretty sure i tighten them well but i will definitely check again tomorrow! Thank you everyone for the suggestions. I cant wait to have a working machine

 

[used red MN]

..There is an anti fouler in all 3 spark plugs. What
should i be looking for in a quality wire? ..
I thought the anti-fouler fish was smelling fairly strong
in your barrel ha-ha.. The increased temperature of the
plug is due to the anti-fouler and not due to it being
loose. Standard Ignition and Belden are fairly well
known brands that at one time had fairly trusted
quality. You really do not need spark plug boots at all,
old Farmalls 1950 an prior came from the factory
without insulating boot on the plug terminals. I am just
saying that to point out extremes you probably do not
want to go that route it is not ideal in damp conditions.
You could remove the anti-foulers and see how long
the plugs last, my guess would be not long. It is
interesting that you found the gap nearly closed on the
one plug when you pulled it out. I would guess the plug
was dropped or the gap was not even checked prior to
installation.
No one has mentioned the other part of the ignition
which is the distributor, you need to check the
condition of the contact points. Should be gapped at
0.020 inch when the distributor cam lobe is turned to
open them to the widest gap. That is the point rubbing
block is at the top of the lobe or the bump, its
positioned by turning the engine if not obvious. Also
you should check the mechanical advance, bump the
starter to see which way the distributor turns. Then
twist the rotor that sets inside the distributor cap the
same direction using your thumb and forefinger. It
should rotate that direction a small distance against
spring tension and when released spring back to near
its original position. If it does not your mechanical
advance is not working properly and needs repaired.
Ignition points condenser these days are not near as
the quality they used to be. They can electrically break
down and cause the ignition to misfire and even stall.
Installing a quality brand such as a Standard Ignition
Blue Streak can at least give you some confidence of
having a reliable one installed. Ignition coils can also
go bad and cause an engine to stall. High external
temperatures of the coil is one indication of a failing
coil.
A compression test measures the ..pressure pumping..
ability of the cylinders. All the plugs are removed, the
throttle pulled wide open and the ignition coil pulled
out of the distributor cap and grounded to a point on
the engine. The tester is screwed in the spark plug
hole and the engine is rotated about 5 turns with the
starter. The gauge then gives you a reading, I would
say a good number would be between 85 and 120. The
air is bled out of the gauge and then moved to the next
cylinder. If for some reason one is found low compared
to the others a teaspoon of oil can be added the
engine spun a couple revolutions and then retest the
cylinder. If the compression come up then the piston
rings are the likely problem. If a very minimal or no
increase this indicates a valve sealing problem. I am
attaching a link to a source for an inexpensive tester
you may also be able to loan out one from an auto
parts store, Oreileys does this if you have one in your
area.
Compression tester