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John Deere with Briggs & Stratt not running correctly

#1

C

cfhsncb

I recently purchased a John Deere LA105. It has about 4 hours on the engine, and was been stored in a climate controlled environment for around 9 years prior to my purchase. Unfortunately it spent most of those 9 years with gas in the fuel system. I have purchased a carb kit from John Deere and rebuilt the carb. I have also replaced the fuel shut-off solenoid. The mower is still not running correctly. I have a video of it running on Youtube. I have attached the link as a text document since I cannot post links yet. It runs mostly fine at low throttle, but cuts out when at high throttle, and gets worse when the engine is under load. Can anyone help, or possibly point me in the right direction?

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  • VideoLink.txt
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#2

BlazNT

BlazNT

The first thing to do is clean out the gas tank. Remove it from the mower and rinse it out. Not a speck of dirt. Next is to replace everything from the fuel tank to carb except for the fuel pump. Remove the carb and clean it really really really well. Compressed air from the carb throat to the fuel pickup side. Never from the pickup side to the throat. I take old speaker wire strands and run them through every hole I can find in the carb throat back to the fuel pickup side. Then spray with carb cleaner making sure not to get any on anything that is not metal. Gasket and rubber do not like carb cleaner. Fresh clean fuel then try again. On a machine that has had fuel in it for that long, you must do all of this. Fuel lines must be replaced with new ethanol resistant fuel lines and the carb must be cleaned to a spotlessness on the inside where you can not see. All the little passages must be clean. Even after all of the cleaning you may still have to replace the carb. If you do replace the carb make sure you still do all the other things of the new carb will get the same problems as the old carb. You must clean the fuel system to like new status or it will all come back in short order.


#3

C

cfhsncb

BlazNT said:
The first thing to do is clean out the gas tank. Remove it from the mower and rinse it out. Not a speck of dirt. Next is to replace everything from the fuel tank to carb except for the fuel pump. Remove the carb and clean it really really really well. Compressed air from the carb throat to the fuel pickup side. Never from the pickup side to the throat. I take old speaker wire strands and run them through every hole I can find in the carb throat back to the fuel pickup side. Then spray with carb cleaner making sure not to get any on anything that is not metal. Gasket and rubber do not like carb cleaner. Fresh clean fuel then try again. On a machine that has had fuel in it for that long, you must do all of this. Fuel lines must be replaced with new ethanol resistant fuel lines and the carb must be cleaned to a spotlessness on the inside where you can not see. All the little passages must be clean. Even after all of the cleaning you may still have to replace the carb. If you do replace the carb make sure you still do all the other things of the new carb will get the same problems as the old carb. You must clean the fuel system to like new status or it will all come back in short order.
Click to expand...

Thanks for taking the time to help me. I have drained the tank, but can't easily clean it since it's mounted below the seat and rear fender. It looks like it would be difficult to remove. I have cleaned and checked all of the fuel lines, and they're all clear, and I'm getting good fuel to the carb. I cleaned the carb when I installed the repair kit. I DID NOT run any wire through all of the carb passages though. I will disassemble it again today and do that.


#4

BlazNT

BlazNT

I thought I got my point across about the fuel lines but I guess not. What happens is the fuel lines start flaking rubber into your fuel. It then gets into your carb that can not handle the particles. This now causes what problems you have. You would think that lawn mower and engine manufacturers would know not to use the fuel line they do but money in the pocket always prevails. You do not have to replace the lines either but I can guarantee you the problem will come back if you do not change them.


#5

Boobala

Boobala

BlazNT said:
I thought I got my point across about the fuel lines but I guess not. What happens is the fuel lines start flaking rubber into your fuel. It then gets into your carb that can not handle the particles. This now causes what problems you have. You would think that lawn mower and engine manufacturers would know not to use the fuel line they do but money in the pocket always prevails. You do not have to replace the lines either but I can guarantee you the problem will come back if you do not change them.
Click to expand...

tumblr_mf9buxoX211r6rrbpo1_500.jpg


#6

C

cfhsncb

BlazNT said:
I thought I got my point across about the fuel lines but I guess not. What happens is the fuel lines start flaking rubber into your fuel. It then gets into your carb that can not handle the particles. This now causes what problems you have. You would think that lawn mower and engine manufacturers would know not to use the fuel line they do but money in the pocket always prevails. You do not have to replace the lines either but I can guarantee you the problem will come back if you do not change them.
Click to expand...

Sorry for the long delay. It's been a busy weekend. I have now replaced all fuel lines, replaced the in-line fuel filter, checked, cleaned, and re-gapped the spark plug, and disassembled the carb once again to run wire through all passages. None of this has made any noticeable difference. I took some photos of the disassembled carb; can you see anything that might be causing the issue? (link is in attached txt document again.) I'm starting to consider just replacing the entire carb. View attachment link.txt


#7

C

cfhsncb

Boobala said:
View attachment 36498
Click to expand...

Thank you for your valuable input.


#8

Boobala

Boobala

cfhsncb said:
Thank you for your valuable input.
Click to expand...

Look fella I posted that sarcasm BECAUSE the tech offered YOU advice that was IMPORTANT to US .. as well as you,.. we are NOT there seeing, touching, smelling or hearing what's going on, maybe you don't understand.. it's BULLSCHITT to O/H a carb and then have a bunch of schitt go into it, because the fuel system was NOT PROPERLY cleaned. these carbs are sensitive to dirt, ( foreign matter) and you CAN'T get the carb to function correctly if the rest of the system is not really clean, and possibly introducing dirt into a clean carb, He told you because it's IMPORTANT ! you save re-diagnosing the same problem over again ! ALSO , it would help if you posted your machines info, JD LA105 is the SERIES we need the model and engine numbers see example ...

GET INFO.JPG


#9

B

bertsmobile1

At the bottom of the white tube is a small chunk of brass.
That is the main jet, push it out slowly noting which way is up
The rebuild kits usually come with a new one cause you take the white plastic housing off tip or blow on it and the main jet ends up in that parallel universe with all of the lost keys and missing left socks.
It is held in place by that tiny O ring
It has a tiny hole in it.
Without it there the engine will start & idle fine but when the throttle opens wide the engine will flood, cough splutter & do what we call 8 stroking.


#10

Boudreaux In Eunice La.

Boudreaux In Eunice La.

I saw the video and I think the idle cuircut is clogged also.... I do a lot of those carbs and a 3rd of them need the welch plug taken out prior to a carb dip........

Bert is correct on that brass jet..... Clean the hole well.... Also there are smaller holes in the long tube that goes in the white tube...

A bunch of them and they need cleaning also with a fine wire..........

Let us know Mon Ami ~!~!


#11

C

cfhsncb

Boobala said:
Look fella I posted that sarcasm BECAUSE the tech offered YOU advice that was IMPORTANT to US .. as well as you,.. we are NOT there seeing, touching, smelling or hearing what's going on, maybe you don't understand.. it's BULLSCHITT to O/H a carb and then have a bunch of schitt go into it, because the fuel system was NOT PROPERLY cleaned. these carbs are sensitive to dirt, ( foreign matter) and you CAN'T get the carb to function correctly if the rest of the system is not really clean, and possibly introducing dirt into a clean carb, He told you because it's IMPORTANT ! you save re-diagnosing the same problem over again ! ALSO , it would help if you posted your machines info, JD LA105 is the SERIES we need the model and engine numbers see example ...

View attachment 36546
Click to expand...

You could have just informed me of that instead of being a sarcastic *******.


#12

C

cfhsncb

bertsmobile1 said:
At the bottom of the white tube is a small chunk of brass.
That is the main jet, push it out slowly noting which way is up
The rebuild kits usually come with a new one cause you take the white plastic housing off tip or blow on it and the main jet ends up in that parallel universe with all of the lost keys and missing left socks.
It is held in place by that tiny O ring
It has a tiny hole in it.
Without it there the engine will start & idle fine but when the throttle opens wide the engine will flood, cough splutter & do what we call 8 stroking.
Click to expand...

Thanks for the reply. Unfortunately my rebuild kit didn't include the jet (thanks JD) I have the old jet still, and while it is clear, it looks a little rough. Your descriptions sounds exactly like the issue I'm having though. Here are some additional photos: https://imgur.com/a/y5geH


#13

C

cfhsncb

Boudreaux In Eunice La. said:
I saw the video and I think the idle cuircut is clogged also.... I do a lot of those carbs and a 3rd of them need the welch plug taken out prior to a carb dip........

Bert is correct on that brass jet..... Clean the hole well.... Also there are smaller holes in the long tube that goes in the white tube...

A bunch of them and they need cleaning also with a fine wire..........

Let us know Mon Ami ~!~!
Click to expand...

Is this the welch plug you're referring to? https://imgur.com/a/Le2Kk The kit did include a new one, but I didn't remove it since it seems to be sealed in. How would I got about removing it?


#14

Boobala

Boobala

Take a look at this, this SHOULD be helpful, and yes that's the welch-plug .

http://outdoorpowerinfo.com/repairs/briggs_intek_single_ohv_nikki_carb.asp


#15

Boobala

Boobala

cfhsncb said:
You could have just informed me of that instead of being a sarcastic *******.
Click to expand...

WELL, I did get my point across, AND ..... you still LUUUUUVVVV me enough to respond, ..:laughing:..:laughing:

Now let's see if we can get you up N runnin !! .. :thumbsup:


#16

Boudreaux In Eunice La.

Boudreaux In Eunice La.

Yep that's the welch plug and Boo sent you a very detailed link.... Now that body of Nikki carbs are the same but some have a different style inside... Some have that spring and some don't....

Just look at yours well when it comes apart.........

Let us know Mon Ami ~!~!


#17

B

bertsmobile1

cfhsncb said:
Is this the welch plug you're referring to? https://imgur.com/a/Le2Kk The kit did include a new one, but I didn't remove it since it seems to be sealed in. How would I got about removing it?
Click to expand...

That is the main jet
A welch plug is a thin dish '
You remove it by driving a small pick through it and levering it out.

Have you been to the Outdoor Equipment link you were given and gone through the step by step rebuild instruction photos ?

The main jet needs to be cleaned with a soft wire brush and the hole cleaned out , a new O ring fitted and then pushed back into the holder with the blunt end of a drill.
Put a dab of vasoline on the new O -Ring so it slides down easily


#18

Boudreaux In Eunice La.

Boudreaux In Eunice La.

cfhsncb,,,,,,,,,,,,,

Like Bert said the Welch plug comes with a sharp punch..... To put it back in, just put it in place and take a 3/16 punch and hammer.......

Lightly tap it in the center until it is indented almost level with the edges......... Pressure holds it in......

Let us know Mon Ami ~!~!


#19

Boudreaux In Eunice La.

Boudreaux In Eunice La.

cfhsncb,,,,,,,,,,,,,,

Yes the part circled in red is the welch plug......... The main jet is the one with the o ring... Just make sure those tiny holes in that brass tube are cleaned out well........ Some might be stopped up and it may look like there are none there...

That carb is corroded / Gummed up / varnished real bad... That's why I suggested the welch plug.............. Seen too many with that issue... especially on generators that haven't ran in a long time.....


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