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Won't Run on New Gas - Will Run on Carb Cleaner

#1

L

LarryJohnson

Can't figure out why mower won't run on gas, but will run on steady stream of carb cleaner. I've been using the old mower for 5 years with no issues. After a number of uses this year, it just stalled out. I assumed the gas was bad, so I emptied the tank, lines, and carb bowl. The only way it will run is with a steady stream of carb cleaner. I visually confirmed the fuel pump is pumping. Don't know what to do next..

Finally got it fixed. Thanks for everyone's help.


#2

Scrubcadet10

Scrubcadet10

i'd clean the carburetor.


#3

L

LarryJohnson

Scrubcadet10 said:
i'd clean the carburetor.
Click to expand...

Thanks for the reply. I sprayed 2 cans of carb cleaner through it trying to get the mower running on gas. Then I removed it, drained the bowl, wiped out a small bit of sediment and replaced. Is that not sufficient?


#4

Scrubcadet10

Scrubcadet10

no.
jets and passage ways need cleaned.


#5

R

Rivets

Plus float level needs to be adjusted.


#6

S

slomo

So this is how some folks clean carbs. Spray a little eye fire juice and call it a day.

Wondering on posts like the OP changed everything on the mower and it still won't run. Cleaned carb and new carb. Guess we need to ask more direct questions? As in how was the carb cleaned?

slomo


#7

S

slomo

LarryJohnson said:
Can't figure out why mower won't run on gas, but will run on steady stream of carb cleaner. I've been using the old mower for 5 years with no issues. After a number of uses this year, it just stalled out. I assumed the gas was bad, so I emptied the tank, lines, and carb bowl. The only way it will run is with a steady stream of carb cleaner. I visually confirmed the fuel pump is pumping. Don't know what to do next..
Click to expand...
Hi Larry,

You need air, fuel, spark and compression to run a mower engine.

Your fuel system "could be" the fuel tank, fuel lines, fuel filters, fuel shut off valve, carb solenoid and finally the carburetor.

So you have air, spark and compression right? It runs on carb cleaner briefly? So what do you think is missing? Right, some gasoline.

Clean or replace your entire fuel system parts as needed.

slomo


#8

L

LarryJohnson

Scrubcadet10 said:
no.
jets and passage ways need cleaned.
Click to expand...

I pulled the carb again, took it apart and sprayed it thoroughly with cleaner. Hit all holes and all bits and pieces. replaced carb and it runs on gasoline halfway..it sputters.
Scrubcadet10 said:
no.
jets and passage ways need cleaned.
Click to expand...

Did as suggested, sprayed every hole and bits and pieces. Carb is clean as a whistle. Managed to start on gas, but at full throttle sputters like it's on one cylinder. When I shut off the key, it revs at normal speed for a few seconds before shutting off.


#9

L

LarryJohnson

slomo said:
Hi Larry,

You need air, fuel, spark and compression to run a mower engine.

Your fuel system "could be" the fuel tank, fuel lines, fuel filters, fuel shut off valve and finally the carburetor.

So you have air, spark and compression right? It runs on carb cleaner briefly? So what do you think is missing? Right, some gasoline.

Clean or replace your entire fuel system parts as needed.

slomo
Click to expand...
No, it would run on carb cleaner indefinitely..and did so until I emptied two cans.


#10

Fish

Fish

What model engine is it?


#11

B

bertsmobile1

Fish said:
What model engine is it?
Click to expand...
Fish,
HE put it in his signature 331877 1371-B1.


Larry,
If that engine has a carb solenoid then check it is retracting fully when energised


#12

L

LarryJohnson

Fish said:
What model engine is it?
Click to expand...
briggs and stratton 406677, type 0344 E1, code 040927YG


#13

L

LarryJohnson

bertsmobile1 said:
Fish,
HE put it in his signature 331877 1371-B1.


Larry,
If that engine has a carb solenoid then check it is retracting fully when energised
Click to expand...

How do I check the solenoid.


#14

B

bertsmobile1

When you turn the ignition on the pin should fully retract
Off the mower a 9V transistor battery is enough to make it retract


#15

Fish

Fish

bertsmobile1 said:
Fish,
HE put it in his signature 331877 1371-B1.


Larry,
If that engine has a carb solenoid then check it is retracting fully when energised
Click to expand...
I believe the internet term would be "LOL"!!


#16

Fish

Fish

Briggs & Stratton Engines 406677-0344-E1 Engine OEM Replacement Parts From eReplacementParts.com

Shop OEM replacement parts by symptoms or model diagrams for your Briggs & Stratton Engines 406677-0344-E1 Engine!
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#17

L

LarryJohnson

bertsmobile1 said:
When you turn the ignition on the pin should fully retract
Off the mower a 9V transistor battery is enough to make it retract
Click to expand...

Not sure where we left off.
I pulled the carb twice over the weekend and cleaned the ba-jesus out of it. Confirmed that the solenoid activated with ignition. Got the mower running, urr partly. Will try to link video.

Listen
IMG_2693 by Larry Johnson, on Flickr


#18

Fish

Fish

How did you clean the carb?


#19

S

slomo

LarryJohnson said:
When I shut off the key, it revs at normal speed for a few seconds before shutting off.
Click to expand...

Fish said:
How did you clean the carb?
Click to expand...
Compressed air was blown on the outside.

slomo


#20

L

LarryJohnson

slomo said:
Compressed air was blown on the outside.

slomo
Click to expand...
Slomo, Why are you responding to a question that was adressed to me?

The carb was taken apart and sprayed with carb cleaner, all holes in carb sprayed with same.


#21

Fish

Fish

Did you take this out and visually verify that it was clear? It is the main jet.

side.PNGtopjet.jpg


#22

Joe Kuhn

Joe Kuhn

@LarryJohnson - I once had a surging problem that was solved by running jet cleaners through the holes in the nut at the bottom of the bowl. Spray and/or air isn't enough sometimes.

See my avatar picture to the left. Jet cleaners are twisted wires of different sizes and often come with new carbs or you can buy them on line easily. My son actually put a jet under a microscope and showed me the fuzz that was around the hole. After the jet cleaners were run through the hole, it was clean and the surging stopped.

This is often my first repair effort if the gas is old, there is surging, or it won't run at all. Of course the bowl can be cleaned as well. I will leave the carb on the machine, take the bowl off, clean the bowl, clean the jets as shown to the left and even the passageway above the nut - with the carb still on the machine. Be careful not to have the float and attached parts fall away.

Good luck and if you need a set of jet cleaners, send me your address in a personal message and I'll mail you some.
1625066597651.png


#23

Beamster

Beamster

My Toro/Briggs was having start and run issues. The bowl was clean but the few bucks spent on a rebuild kit with jet cleared it right up. It's a mystery to me because nothing looked amiss but I'll take the little victories without question.


#24

Scrubcadet10

Scrubcadet10

Joe Kuhn said:
Once had a surging problem that was solved by running jet cleaners through the holes in the nut at the bottom of the bowl. Spray and/or air isn't enough sometimes.

See my avatar picture to the left. Jet cleaners are twisted wires of different sizes and often come with new carbs or you can buy them on line easily. My son actually put a jet under a microscope and showed me the fuzz that was around the hole. After the jet cleaners were run through the hole, it was clean and the surging stopped.

This is often my first repair effort if the gas is old, there is surging, or it won't run at all. Of course the bowl can be cleaned as well. I will leave the carb on the machine, take the bowl off, clean the bowl, clean the jets as shown to the left and even the passageway above the nut - with the carb still on the machine. Be careful not to have the float and attached parts fall away.

Good luck and if you need a set of jet cleaners, send me your address in a personal message and I'll mail you some.
View attachment 57195
Click to expand...
that's something i've never thought of.... putting a jet under a microscope to have a look see..... may order a Hubble style telescope .....


#25

Joe Kuhn

Joe Kuhn

Scrubcadet10 said:
that's something i've never thought of.... putting a jet under a microscope to have a look see..... may order a Hubble style telescope .....
Click to expand...
Haha. We used a kid's microscope from when our kids were little. I bought one with a phone attachment so I could take pictures and post them, but haven't gotten around to it.


#26

L

LarryJohnson

Joe Kuhn said:
@LarryJohnson - I once had a surging problem that was solved by running jet cleaners through the holes in the nut at the bottom of the bowl. Spray and/or air isn't enough sometimes.

See my avatar picture to the left. Jet cleaners are twisted wires of different sizes and often come with new carbs or you can buy them on line easily. My son actually put a jet under a microscope and showed me the fuzz that was around the hole. After the jet cleaners were run through the hole, it was clean and the surging stopped.

This is often my first repair effort if the gas is old, there is surging, or it won't run at all. Of course the bowl can be cleaned as well. I will leave the carb on the machine, take the bowl off, clean the bowl, clean the jets as shown to the left and even the passageway above the nut - with the carb still on the machine. Be careful not to have the float and attached parts fall away.

Good luck and if you need a set of jet cleaners, send me your address in a personal message and I'll mail you some.
View attachment 57195
Click to expand...

Hey thanks for all the suggestions. I found another issue yesterday..gas in the oil.
Based on my limited knowledge and few things I've read, I think what happened was debris caused the carb float to stay up allowing gas to get in the oil. I compounded the problem by pouring gas down carb throat when trying to start. So I've flushed and changed the oil and filter. Will change again shortly after getting engine running properly.
I also found a leak in the carb, so I need to pull it again and replace bowl o-ring. I bought two new ones. I'll check main jet at that time. Honestly, I don't recall seeing where that's located on the carb.
Looking at a used John Deere this evening...been wanting a new mower..but will still work to get this running properly.


#27

Beamster

Beamster

LarryJohnson said:
Hey thanks for all the suggestions. I found another issue yesterday..gas in the oil.
Based on my limited knowledge and few things I've read, I think what happened was debris caused the carb float to stay up allowing gas to get in the oil. I compounded the problem by pouring gas down carb throat when trying to start. So I've flushed and changed the oil and filter. Will change again shortly after getting engine running properly.
I also found a leak in the carb, so I need to pull it again and replace bowl o-ring. I bought two new ones. I'll check main jet at that time. Honestly, I don't recall seeing where that's located on the carb.
Looking at a used John Deere this evening...been wanting a new mower..but will still work to get this running properly.
Click to expand...
Happens all the time with old motorbikes that have a petcock that gets left on. Many naysayers claim that the float keeps the gas from flowing when off but you (and I) have found out otherwise. Unfortunately few mowers have a shutoff.


#28

R

Rivets

Those “jet cleaners” are actually acetylene torch tip cleaners, which are files and from my experience wouldn’t recommend using on a carb fuel jet. They will enlarge the jet size. Just my opinion.


#29

M

mystic240

If a jet or passage is plugged it will need a small wire or some mechanical means to unplug it.


#30

L

LarryJohnson

Fish said:
Did you take this out and visually verify that it was clear? It is the main jet.

View attachment 57189View attachment 57190
Click to expand...

So where's me jet. Is it under the shiney cover I'm pointing to below, or is it that shaft in the middle. The shaft has three little holes in it. Or maybe it's down inside the shaft.

Untitled by Larry Johnson, on Flickr

Untitled by Larry Johnson, on Flickr


#31

S

slomo

LarryJohnson said:
The carb was taken apart and sprayed with carb cleaner, all holes in carb sprayed with same.
Click to expand...
UPDATE - "The carb was taken apart and sprayed with carb cleaner, all holes in carb sprayed with same."


#32

S

slomo

Joe Kuhn said:
@LarryJohnson - I once had a surging problem that was solved by running jet cleaners through the holes in the nut at the bottom of the bowl. Spray and/or air isn't enough sometimes.

See my avatar picture to the left. Jet cleaners are twisted wires of different sizes and often come with new carbs or you can buy them on line easily. My son actually put a jet under a microscope and showed me the fuzz that was around the hole. After the jet cleaners were run through the hole, it was clean and the surging stopped.

This is often my first repair effort if the gas is old, there is surging, or it won't run at all. Of course the bowl can be cleaned as well. I will leave the carb on the machine, take the bowl off, clean the bowl, clean the jets as shown to the left and even the passageway above the nut - with the carb still on the machine. Be careful not to have the float and attached parts fall away.

Good luck and if you need a set of jet cleaners, send me your address in a personal message and I'll mail you some.
View attachment 57195
Click to expand...
These are the worst thing you can use to unclog a soft brass jet. They are abrasive and will enlarge the brass orifice size.

What I use is fishing line. Monofilament fishing line is made out of nylon. Nylon is softer than brass. Use like 2-4lb test for pilot jets. 10-30lb line for main jets. Simply toss in the trash when done. It bends easy if need be while cleaning too.

slomo


#33

Joe Kuhn

Joe Kuhn

Rivets said:
Those “jet cleaners” are actually acetylene torch tip cleaners, which are files and from my experience wouldn’t recommend using on a carb fuel jet. They will enlarge the jet size. Just my opinion.
Click to expand...
Good clarification!

Carb jet cleaners are spun wire:

1625095441056.png

Torch tip cleaners are files:

1625095543990.png


#34

Joe Kuhn

Joe Kuhn

slomo said:
These are the worst thing you can use to unclog a soft brass jet. They are abrasive and will enlarge the brass orifice size.

What I use is fishing line. Monofilament fishing line is made out of nylon. Nylon is softer than brass. Use like 2-4lb test for pilot jets. 10-30lb line for main jets. Simply toss in the trash when done. It bends easy if need be while cleaning too.

slomo
Click to expand...
I've not had any problems with the spun wire cleaners. They're pretty soft so you can't apply a lot of pressure with them. I am careful...Your point is well taken. We're removing debris, not expanding the inside diameter.


#35

R

Ronni

LarryJohnson said:
Can't figure out why mower won't run on gas, but will run on steady stream of carb cleaner. I've been using the old mower for 5 years with no issues. After a number of uses this year, it just stalled out. I assumed the gas was bad, so I emptied the tank, lines, and carb bowl. The only way it will run is with a steady stream of carb cleaner. I visually confirmed the fuel pump is pumping. Don't know what to do next..
Click to expand...
Your jets might be clogged in the carburetor. Gasoline can sulfate if it gets old and will clog your carburetor jets. If you can't clean those jets, you may have to buy a new carburetor. You can prevent this from happening in the future by using something like STA-BIL 360 Protection Ethanol Treatment And Fuel Stabilizer.


#36

L

LarryJohnson

Ronni said:
Your jets might be clogged in the carburetor. Gasoline can sulfate if it gets old and will clog your carburetor jets. If you can't clean those jets, you may have to buy a new carburetor. You can prevent this from happening in the future by using something like STA-BIL 360 Protection Ethanol Treatment And Fuel Stabilizer.
Click to expand...
Couldn't find the jet. See post 30.
Had trouble with the bizarre main o-ring as well. Decided to buy a new carb, just $20 for new complete unit on eBay.


#37

Joe Kuhn

Joe Kuhn

Isn't your main jet being pointed to here with a punch?

1625103081643.png
I'm after clarification. Not saying you shouldn't have bought new.


#38

D

Don Lanier

Spraying Carb Cleaner thru a running engine doesn't CLEAN the carburetor, you need to remove the carb, disassemble, and spray and soak the parts to thoroughly clean it, Hydro Tank would be best, using Welding tip cleaners to pass through all the orifices, jets, Main Jet, Remove the Float, Needle Valve, and clean the tips and passages, spraying carb cleaner through a running engine may remove some carbon from the combustion chamber, but does nothing to the Carb itself. We have seen this issue repeatedly this year and its worse every day, whatever is coming out of the refinery's with the ethanol is barely good for Power Equipment, We always recommend 89 octane as it has a better detergent package, but the ethanol will deteriorate and ruin parts over time.


#39

matt man

matt man

On carb jets did you poke with say a tip cleaner or like a guitar string


#40

SARG

SARG

LarryJohnson said:
Couldn't find the jet. See post 30.
Had trouble with the bizarre main o-ring as well. Decided to buy a new carb, just $20 for new complete unit on eBay.
Click to expand...
After 50 years of dicking with small engines that are not running right and the issue seems to be fuel related ............. I buy a new carb ............ fussing around trying to remedy carb problems is a true source of frustration


#41

W

Wildbill58

Just a thought, I'm sure everyone has more insight than I, but ...How old is your gas, I've had a couple times been unable to run a sled on older ethanol gas (Older than 2-3 months ) It looses octane rating and absorbs water and won't not run or run ruff, resolved with fresh fuel....Just my 2 cents


#42

B

bertsmobile1

Wildbill58 said:
Just a thought, I'm sure everyone has more insight than I, but ...How old is your gas, I've had a couple times been unable to run a sled on older ethanol gas (Older than 2-3 months ) It looses octane rating and absorbs water and won't not run or run ruff, resolved with fresh fuel....Just my 2 cents
Click to expand...
Not quite right
It looses the parts that are volatile at room temperature called aromatics
These evaporate out of the fuel because they vapourise at room temperature.
Nothing to do with octane rating
Can be regenerated by adding a few mil of acetone.

Water adsorbed does not prevent the engine from starting unless it has filled the float bowl to the height of the main jet


#43

L

LarryJohnson

slomo said:
These are the worst thing you can use to unclog a soft brass jet. They are abrasive and will enlarge the brass orifice size.

What I use is fishing line. Monofilament fishing line is made out of nylon. Nylon is softer than brass. Use like 2-4lb test for pilot jets. 10-30lb line for main jets. Simply toss in the trash when done. It bends easy if need be while cleaning too.

slomo
Click to expand...

Would an ultrasonic cleaning of the carb be sufficient...and do you think the Harbor Freight unit would do the trick.


#44

S

slomo

LarryJohnson said:
Would an ultrasonic cleaning of the carb be sufficient...and do you think the Harbor Freight unit would do the trick.
Click to expand...
How many engines do you have? Just a mower and trimmer I would pass on the ultra magic cleaner. Most all of the cheap ones don't clean worth a darn anyway. You have to spend like 1500 bucks to get a good one. But hey I've never owned one so don't listen to me. Just what I've seen on youtube. PASS on the HF cleaner box.

Get a can or 2 or carb cleaner and some fishing line. Much cheaper than some magic cleaning box that you will have to store.

Besides if you bought a $10,000 cleaner box, you still have to rod out the jets and blow out with compressed air. I can clean 3 carbs by the time one cleaning cycle finishes.

slomo


#45

Fish

Fish



#46

L

LarryJohnson

Fish said:
Click to expand...
Excellent! I never saw such a jet in my carb.


#47

L

LarryJohnson

It's alive! The cheap $20 after-market carb arrived broken, so a refund was issued. Fortunately, i also ordered a cheap rebuilt kit for the carb. Between the new parts and old, managed to get everthing back together and fired right up with the aid of a jump battery. Will replace the battery soon.


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