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Hope someone can help

#1

M

macdoesit

I have a new Z325E Zero turn JD mower. Bought 2 months ago. 30 hours on it. Mowing today and when I disengaged the mower blades it started surging, like moving the throttle up and down. When a load is put on it, like mowing it does not surge. I cleaned my 5 gallon gas can, went to a different gas station frilled it up, came back, disconnected fuel line from mower gas tank, installed new gas filter, put gas line into gas can a couple inches below gas level, started the mower ran it 10 minutes and it still surged. It is under warranty, so I called the dealer that would be working on it. First thing they said was bad gas. I filled up 3- 5 gallon cans 2 weeks ago and used one can and no problem till today.


#2

S

SeniorCitizen

I have a new Z325E Zero turn JD mower. Bought 2 months ago. 30 hours on it. Mowing today and when I disengaged the mower blades it started surging, like moving the throttle up and down. When a load is put on it, like mowing it does not surge. I cleaned my 5 gallon gas can, went to a different gas station frilled it up, came back, disconnected fuel line from mower gas tank, installed new gas filter, put gas line into gas can a couple inches below gas level, started the mower ran it 10 minutes and it still surged. It is under warranty, so I called the dealer that would be working on it. First thing they said was bad gas. I filled up 3- 5 gallon cans 2 weeks ago and used one can and no problem till today.
Bad Gas is the standard when they have no clue . .Put Champion plugs in it .


#3

H

hlw49

Treat the fuel with sea foam. Take the fuel filter loose and drain the fuel out of it fill it with sea foam. Start and run see if that clears it up.


#4

A

Auto Doc's

I have a new Z325E Zero turn JD mower. Bought 2 months ago. 30 hours on it. Mowing today and when I disengaged the mower blades it started surging, like moving the throttle up and down. When a load is put on it, like mowing it does not surge. I cleaned my 5 gallon gas can, went to a different gas station frilled it up, came back, disconnected fuel line from mower gas tank, installed new gas filter, put gas line into gas can a couple inches below gas level, started the mower ran it 10 minutes and it still surged. It is under warranty, so I called the dealer that would be working on it. First thing they said was bad gas. I filled up 3- 5 gallon cans 2 weeks ago and used one can and no problem till today.
Bad gas is usually from them leaving fuel in them while on the sale line. Fuel left sitting degrades especially with heat and sudden changes in the weather.

Most likely, they need to pull the carburetor and give it a proper cleaning. This machine likely sat on display for months with old fuel gradually starting to turn to a light varnish inside the carburetor bowl. That varnish will stay there for quite a few hours of initial run time until multiple refills with fresh fuel start breaking it down. At that point it slowly turns the varnish to a gel, and that begins choking down the small passages inside the carburetor.

I had this issue several times when I was a service manager for a local John Deere dealer. I began making sure to use only non-ethanol and that all of the fuel we used had stabilizer in it. The problems went away in a very short time.

As an FYI, John Deere does not warranty bad fuel claims, so the shop typically puts it off on the customer to pay for correcting the issue. If the service manager is helpful and creative, they will find a way to warranty the carburetor for "casting porosity" so it can be covered.


#5

sgkent

sgkent

take it to them. They cannot diagnosis it over the phone. If you mess with it, they can say you screwed it up. Could be a small spec of dirt in an idle circuit. There is a warranty.


#6

Tiger Small Engine

Tiger Small Engine

take it to them. They cannot diagnosis it over the phone. If you mess with it, they can say you screwed it up. Could be a small spec of dirt in an idle circuit. There is a warranty.
A big box store will refer you to a local shop and it will cost to fix. A good dealer will make it right for no charge (where you bought it).


#7

StarTech

StarTech

Sure you not using the JD dealer here? They couldn't even find a bad spark plug and told another customer that his engine didn't have an oil pump even it tough had an oil filter in plain sight and said just ignore the oil pressure light. That customer won't even allow JD techs touch his equipment even under warranty.

Did said most likely it a restriction in the carburetor idle circuit.


#8

M

macdoesit

Bad gas is usually from them leaving fuel in them while on the sale line. Fuel left sitting degrades especially with heat and sudden changes in the weather.

Most likely, they need to pull the carburetor and give it a proper cleaning. This machine likely sat on display for months with old fuel gradually starting to turn to a light varnish inside the carburetor bowl. That varnish will stay there for quite a few hours of initial run time until multiple refills with fresh fuel start breaking it down. At that point it slowly turns the varnish to a gel, and that begins choking down the small passages inside the carburetor.

I had this issue several times when I was a service manager for a local John Deere dealer. I began making sure to use only non-ethanol and that all of the fuel we used had stabilizer in it. The problems went away in a very short time.

As an FYI, John Deere does not warranty bad fuel claims, so the shop typically puts it off on the customer to pay for correcting the issue. If the service manager is helpful and creative, they will find a way to warranty the carburetor for "casting porosity" so it can be covered.
The problem started at 30 hours, so what you said makes sense. When I bought it, I started it to load on my trailer, after loading, it immediately died. On the way home I stopped at a station to get gas in my pickup, and also filled up the mower, (100% gas) I have never used ethanol in any machine I own. It started right up after gas reached the carb and it ran like a champ till yesterday at 30.7 hours. The weird thing is, when I engage movement or engage the blades the surging stops, I can also hear a very faint popping from exhaust. Is there an additive to mix with gas to dissolve the varnish?
(I also copied your response so I can show it to the dealer shop manager.)


#9

M

macdoesit

A big box store will refer you to a local shop and it will cost to fix. A good dealer will make it right for no charge (where you bought it).
Bought it from Lowes. In Mustang, Oklahoma.


#10

M

macdoesit

Treat the fuel with sea foam. Take the fuel filter loose and drain the fuel out of it fill it with sea foam. Start and run see if that clears it up.
I put seafoam in the first tank of gas.


#11

M

macdoesit

First thing dealer said was, they have had a lot of customers in the past 2 weeks with same problem and contributed it to bad gas they told the customers to add HEET to the gas and was told by the customers it fixed the problem. (??)


#12

M

macdoesit

Bad Gas is the standard when they have no clue . .Put Champion plugs in it .
For warranty I don't want to change anything for now.


#13

A

Auto Doc's

Hello macdoesit,

The local JD dealer is who uncrates and performs the make ready for sale on new riders for the big box stores (It's in their JD sales contract to carry the JD products.)

They get minimal fuel put in them for a quick test run and then they set on display for months before being sold.

As for fuels: Consider all fuels to be a refined "blended solvent", as it ages it breaks down and oxidizes if left sitting.

I see many new mowers, push, rider and zero-turn around my area (that don't go to the dealer) at about the 20–30-hour mark for this kind of problem. They are happy to pay me instead of the dealer pick-up and delivery charge it would cost them to have a possible warranty repair done.


#14

M

macdoesit

Hello macdoesit,

The local JD dealer is who uncrates and performs the make ready for sale on new riders for the big box stores (It's in their JD sales contract to carry the JD products.)

They get minimal fuel put in them for a quick test run and then they set on display for months before being sold.

As for fuels: Consider all fuels to be a refined "blended solvent", as it ages it breaks down and oxidizes if left sitting.

I see many new mowers, push, rider and zero-turn around my area (that don't go to the dealer) at about the 20–30-hour mark for this kind of problem. They are happy to pay me instead of the dealer pick-up and delivery charge it would cost them to have a possible warranty repair done.
Thank you.
Do you think it would do any good to put a bottle of HEET in the gas. The only mower mechanic around here retired 6 months ago. If I have to take to dealer, I have a trailer, so delivery is no problem.


#15

A

Auto Doc's

First thing dealer said was, they have had a lot of customers in the past 2 weeks with same problem and contributed it to bad gas they told the customers to add HEET to the gas and was told by the customers it fixed the problem. (??)
Hi macdoesit,

Using HEET is not a bad suggestion in my opinion. Honestly, I forgot about that.

HEET is basically a bottle of Methanol fuel solvent (petrol) (Not to be confused with Ethanol (corn). It has to be churned in a fuel can, not just poured in the tank to be effective.


#16

S

slomo

Taryl debunked the alcohol removes water from gas. So did Chickanic if I recall correctly. Heet is a wallet draining item that does not work. Project Farm I think did a video on this too I think??

Why would you use seafoam, on any engine? Nothing but a solvent with some oil. A new engine doesn't need this. It's not going to protect anything in the engine. If it DID work, Briggs, Kawasaki and the like would recommend it in their engine manuals. Never seen any recommendation other than E-10 or less, 87 octane or higher. Seafoam was actually made for 2 stroke engines. This guy owns a 4 stroke. So after the OP used seafoam, he STILL has an issue.

I agree on the dealer call and them blaming the fuel. That is the first trick in their book. They don't have a clue even most times after looking at the mower in person.


#17

A

Auto Doc's

Taryl debunked the alcohol removes water from gas. So did Chickanic if I recall correctly. Heet is a wallet draining item that does not work. Project Farm I think did a video on this too I think??

Why would you use seafoam, on any engine? Nothing but a solvent with some oil. A new engine doesn't need this. It's not going to protect anything in the engine. If it DID work, Briggs, Kawasaki and the like would recommend it in their engine manuals. Never seen any recommendation other than E-10 or less, 87 octane or higher. Seafoam was actually made for 2 stroke engines. This guy owns a 4 stroke. So after the OP used seafoam, he STILL has an issue.

I agree on the dealer call and them blaming the fuel. That is the first trick in their book. They don't have a clue even most times after looking at the mower in person.
Hi slomo,

If I believed everything You Tube shows us, there would not much else in life to do but be a pessimist. Those shows tend to be very biased and flip flop opinions based on conjecture.

Alcohol does not "remove" water; it breaks it down and encapsulates it so it can pass through with the fuel in a microscopic form.

HEET is not cheap, but it has been a proven product for years.

I'm not a big fan of Seafoam, never have been.

Here lately I've been fighting a rash of canned Trufuel victims with 2-stroke engines. That high priced "special" fuel breaks down if on the store shelves too long, and it gets worse once the can is opened and left only partially full. I have come to dislike 2-stroke weed eaters because they turn out to be bigger problems than most other lawn equipment.


#18

M

macdoesit

Taryl debunked the alcohol removes water from gas. So did Chickanic if I recall correctly. Heet is a wallet draining item that does not work. Project Farm I think did a video on this too I think??

Why would you use seafoam, on any engine? Nothing but a solvent with some oil. A new engine doesn't need this. It's not going to protect anything in the engine. If it DID work, Briggs, Kawasaki and the like would recommend it in their engine manuals. Never seen any recommendation other than E-10 or less, 87 octane or higher. Seafoam was actually made for 2 stroke engines. This guy owns a 4 stroke. So after the OP used seafoam, he STILL has an issue.

I agree on the dealer call and them blaming the fuel. That is the first trick in their book. They don't have a clue even most times after looking at the mower in person.
It is a new mower 30 hours. I clean the whole mower, frame engine after every mow, 5 acres.


#19

M

macdoesit

Hi macdoesit,

Using HEET is not a bad suggestion in my opinion. Honestly, I forgot about that.

HEET is basically a bottle of Methanol fuel solvent (petrol) (Not to be confused with Ethanol (corn). It has to be churned in a fuel can, not just poured in the tank to be effective.
What do you mean, churned in a fuel can? How long does it take for the HEET to work? If it is just for bad gas, I have already taken the gas tank off, drained all gas, I had to jerry rig a shop vac to suck all the gas out because there is an inner sleeve in the neck of the gas fill spout. When you turn the gas tank upside down about a half quart collects into this inner sleeve, you have to turn the tank right side up and fenagle a hose jerry-rigged to the shop vac hose down into the odd shaped gas fill spout to suck the remaining gas, etc out. I don't understand why JD would do this, completely stupid.


#20

M

macdoesit

The JD dealer is in Shawnee, OK. they sale and work on large, small JD tractors, skid steers and mowers. I'm getting ready to load it on my trailer and take it to them.


#21

A

Auto Doc's

What do you mean, churned in a fuel can?
Mix it according to instructions in the fuel can/jug being used, then gently shake the fuel/jug around to mix it (churn it).

Sometimes my Southern vocabulary is not quite understood. LOL


#22

M

macdoesit

Mix it according to instructions in the fuel can/jug being used, then gently shake the fuel/jug around to mix it (churn it).
Will it clean the carb ?


#23

A

Auto Doc's

I would not expect anything immediate, but I have seen it work. Run it and get the fuel mix down in the carburetor well, then let it set and see if it works its magic.


#24

Tiger Small Engine

Tiger Small Engine

I would not expect anything immediate, but I have seen it work. Run it and get the fuel mix don in the carburetor well, then let it set and see if it works its magic.
Heet allows the fuel and water to mix so that a tiny amount of water can be burned with the gas. Heet will not overcome large amounts of water. The label says one once of Heet per gallon.

I would say your mower with 30 hours on it has either older gas, or gas with water in it, and possibly needs a carburetor cleaning as well for it to run 100% right.

Seafoam contains 4 main ingredients, with one of them being the same as Heet. People love taking shortcuts in life, but they often don’t work.

One of the downsides to buying from a big box store is lack of service after the sale. You are just a number to them, and a customer for the local small engine shop.


#25

M

macdoesit

Heet allows the fuel and water to mix so that a tiny amount of water can be burned with the gas. Heet will not overcome large amounts of water. The label says one once of Heet per gallon.

I would say your mower with 30 hours on it has either older gas, or gas with water in it, and possibly needs a carburetor cleaning as well for it to run 100% right.

Seafoam contains 4 main ingredients, with one of them being the same as Heet. People love taking shortcuts in life, but they often don’t work.

One of the downsides to buying from a big box store is lack of service after the sale. You are just a number to them, and a customer for the local small engine shop.
Gas is always fresh. Bought the mower June/16/2025.


#26

M

macdoesit

Took the mower to JD, will let you all know what happens. Thank you for all the help.


#27

R

RevB

Took the mower to JD, will let you all know what happens. Thank you for all the help.
I'm right over by Will Rogers airport on the west side...let us know what JD has to say....


#28

M

macdoesit

I'm right over by Will Rogers airport on the west side...let us know what JD has to say....
Will do. Do you know of a good mower mechanic, reasonable rates?


#29

R

RevB

Will do. Do you know of a good mower mechanic, reasonable rates?
I have taken care of my neighbor's machines and mine....two stroke or four. I do it for free because we all have a lot of yard and last year one of them took their Zero Turn to a shop and they just never got to it in 4 weeks. I mowed their lawn for free, too. Hell to cut if it gets too long. They went and got it and I fixed it in an afternoon. Simple. The other neighbor had a weed whacker that someone before had really butchered on a repair to the clutch. Fixed that but took about a week to get the new clutch off Ebay.

Anyway...I'm not advertising just sometimes I have some time to look at something....for free. 🤫


#30

M

macdoesit

JD called today, said mower was ready, water in the fuel pickup. It runs perfect so far. When surging first started last week, I took the fuel tank off and drained it. Disconnected fuel line from tank, started mower and ran all gas out of line till mower died. I put gas in a mason jar and let it sit over night, no water in the jar. I put the gas line in the jar about 1 inch down, cranked mower till it started, ran it for 20 minutes and it surged the whole time. I don't understand this.


#31

sgkent

sgkent

well, one of two things will happen. If JD is correct, the surging will stop. If JD is wrong, it will be back. Water can collect in the very bottom of the carb bowl, in dips in a fuel line, low spots in the tank where you can only get it by adding something like Heet (Isopropyl alcohol) or using a bent rod to maneuver a clean rag around the drained tank - strange places like that which you think you got it all when you did not.


#32

A

Auto Doc's

Hi macdoesit,

The trouble is that it only takes 1 drop of water getting caught in the fuel bowl to disrupt fuel being drawn in by the carburetor jets. Water is heavier than gasoline and they are totally opposing liquids.


#33

R

RevB

JD called today, said mower was ready, water in the fuel pickup. It runs perfect so far. When surging first started last week, I took the fuel tank off and drained it. Disconnected fuel line from tank, started mower and ran all gas out of line till mower died. I put gas in a mason jar and let it sit over night, no water in the jar. I put the gas line in the jar about 1 inch down, cranked mower till it started, ran it for 20 minutes and it surged the whole time. I don't understand this.
Well..."water". Let's look for root cause. 1. Mower stored indoors? 2. Fuel cans stored indoors? 3. Same Fuel cans? 4. Fuel obtained from same, well used gas station?

I don't recall having any flooding lately. Nor has it been excessively humid. As for putting gas in a mason jar....unless you put all of the gas in one huge mason jar, a random sample is not an indicator. The water dissociates immediately if straight gas but takes awhile with 10% ethanol gas because some of the water binds with the alcohol and thereby becomes miscible. When the alcohol becomes saturated then the water has nothing to bind to and dissociates immediately.


#34

M

macdoesit

I will run it 30 minutes around property for several days and do an update. The gas tank is awful and JD probably made it this way so you have to take mower in to drain tank. At the top of the fuel inlet neck there is an inner sleeve molded into the neck, when you turn tank upside-down about a half quart runs into this sleeve. My prior JD 54" did not have this sleeve.


#35

R

RevB

I will run it 30 minutes around property for several days and do an update. The gas tank is awful and JD probably made it this way so you have to take mower in to drain tank. At the top of the fuel inlet neck there is an inner sleeve molded into the neck, when you turn tank upside-down about a half quart runs into this sleeve. My prior JD 54" did not have this sleeve.
Up in PA several years ago a neighbor had a JD that would just die. Did all the normal investigations and determined it was a fuel issue. Looked into the tank and was amazed. Quite a bit of organic debris floating about including little leaf chunks. The amazing part there was no filter at the end of the intake hose, just a flat, cut off end. Fired it up and watched a leaf chunk float over to the end and get sucked onto it. Died in about 30 seconds then the chunk fell off. Cleaned the tank with my shop vac after siphoning as much as I could (couple teaspoons left) and put a proper sintered bronze filter on the end of the hose. Never failed again.


#36

sgkent

sgkent

These things happen with water and fuel. A ground / instrument school instructor I had came into the class one day and told an interesting story that had happened to him that morning. He had a three hour round trip flight scheduled with another pilot he was checking out. They did a pre flight, took the plane up for 15 minutes, landed and went to a light breakfast before the flight. Told the FBO to top off the plane with fuel. When they came back out the other pilot started pre flighting, and the instructor told her that they just did it like 30 minutes earlier, but she insisted. So he told us, " I am standing there watching her and she is punching the tank, filling the jar and throwing the fuel out onto the tarmac. She does it like five times. So I say hand me the punch cup and I will show you how to do it, you only need about and inch in the bottom of the cup to see if there is water." So he says, "I punch the tank and the fluid is clear with no color. I sniff it. No smell. So I do it like three more times, No fuel. Only water." Heavy rain the night before flowed across the field in the area the underground tanks are filled and one of the caps was loose, the tanker filled up just before topping off their plane, and it is full of water. 7 planes end up grounded with their fuel systems having to be completely decontaminated at the FBO's expense - thankfully none had tried to take off yet. So the moral is, just because you have new fuel does not always mean that it can't accidentally have a little water in it (or a lot as in this true story). The instructor added of course he felt really lucky his student found it, and not when the engine died on takeoff. He said he always punches the fuel now before each flight, regardless, even if they just landed and he is running in to hit the restroom and grab a pepsi before the next flight.


#37

A

Auto Doc's

These things happen with water and fuel. A ground / instrument school instructor I had came into the class one day and told an interesting story that had happened to him that morning. He had a three hour round trip flight scheduled with another pilot he was checking out. They did a pre flight, took the plane up for 15 minutes, landed and went to a light breakfast before the flight. Told the FBO to top off the plane with fuel. When they came back out the other pilot started pre flighting, and the instructor told her that they just did it like 30 minutes earlier, but she insisted. So he told us, " I am standing there watching her and she is punching the tank, filling the jar and throwing the fuel out onto the tarmac. She does it like five times. So I say hand me the punch cup and I will show you how to do it, you only need about and inch in the bottom of the cup to see if there is water." So he says, "I punch the tank and the fluid is clear with no color. I sniff it. No smell. So I do it like three more times, No fuel. Only water." Heavy rain the night before flowed across the field in the area the underground tanks are filled and one of the caps was loose, the tanker filled up just before topping off their plane, and it is full of water. 7 planes end up grounded with their fuel systems having to be completely decontaminated at the FBO's expense - thankfully none had tried to take off yet. So the moral is, just because you have new fuel does not always mean that it can't accidentally have a little water in it (or a lot as in this true story). The instructor added of course he felt really lucky his student found it, and not when the engine died on takeoff. He said he always punches the fuel now before each flight, regardless, even if they just landed and he is running in to hit the restroom and grab a pepsi before the next flight.
Hi sgkent,

I work on a lot of hay hauler big trucks along with other equipment and I had one truck come in with a chronic lack of power and stalling under load. I pulled the 2 large diesel filters, and one had a section of a plastic shopping bag stretching out of the filter housing has I lowered the filter. I used a coat hanger and inspection camera to fish out 2 more partial bags out of the saddle tanks, blew the lines clear with compressed air, then installed new filters and primed it. The truck ran strong under load after that.

As the story goes "Just when you think you've seen everything", expect something new and unexpected to happen.

I also get quite a few mowers with diesel/gas mixed in them because people aren't familiar with the difference in smell of the two. Makes a heck of a mosquito fogger if it will run at all. Many do not realize that a red fill can/jug is for gasoline only, and a yellow can/jug is meant for diesel only.


#38

R

RevB

These things happen with water and fuel. A ground / instrument school instructor I had came into the class one day and told an interesting story that had happened to him that morning. He had a three hour round trip flight scheduled with another pilot he was checking out. They did a pre flight, took the plane up for 15 minutes, landed and went to a light breakfast before the flight. Told the FBO to top off the plane with fuel. When they came back out the other pilot started pre flighting, and the instructor told her that they just did it like 30 minutes earlier, but she insisted. So he told us, " I am standing there watching her and she is punching the tank, filling the jar and throwing the fuel out onto the tarmac. She does it like five times. So I say hand me the punch cup and I will show you how to do it, you only need about and inch in the bottom of the cup to see if there is water." So he says, "I punch the tank and the fluid is clear with no color. I sniff it. No smell. So I do it like three more times, No fuel. Only water." Heavy rain the night before flowed across the field in the area the underground tanks are filled and one of the caps was loose, the tanker filled up just before topping off their plane, and it is full of water. 7 planes end up grounded with their fuel systems having to be completely decontaminated at the FBO's expense - thankfully none had tried to take off yet. So the moral is, just because you have new fuel does not always mean that it can't accidentally have a little water in it (or a lot as in this true story). The instructor added of course he felt really lucky his student found it, and not when the engine died on takeoff. He said he always punches the fuel now before each flight, regardless, even if they just landed and he is running in to hit the restroom and grab a pepsi before the next flight.
I was of the same mind set. My last aircraft was a Bellanca Super Viking, 4 tanks, two on either side. I'd never let anyone fuel it because the inside tanks would fill really slowly so I'd have to do the left then the right, come back to the left and then back to the right. The out board tanks did not suffer the same problem. Now you also had to remember if you ran any tanks dry and those were usually the outboards as I'd never let the inboard mains run dry. On run up I'd bring it up to mag check RPMs and cycle through all the tanks for at least a minute each just to be sure. The gauges weren't all that reliable in terms of quantity so I labeled them EMPTY AT 1/4. Mostly tanks were run based on time as GPH was known and was reliable. Running a tank dry in the air was no problem, you'd just have to watch the fuel flow indicator and when it started to bounce you switched tanks. If you got busy the "Brrrrup! Burrrup!!!" would get your attention and you'd switch.


#39

sgkent

sgkent

Auto Doc - interesting read. One has to wonder how does someone get multiple plastic baggies in the fuel tank except by sabotage? I know friends who have pulled tee shirts and socks out of gasoline tanks in collector cars when restoring them.

Rev-B - also an interesting read. John Denver crashed and died when he ran out of fuel on the main tank. The kit builder put the fuel selector over the pilot's shoulder instead of the recommended lower position on the floor or wing root. Denver never did anything with that, surprising because his father was an Air Force officer who flew, so Denver grew up knowing risks of flying. I say that because my dad was a career USCG SARS pilot and officer, and I know the many stories of his experiences of how easily things can go south to the unsuspecting / unprepared. Denver's fuel was low when he took off, someway inebriated, telling the FBO that he had enough fuel with his reserves to make the short trip home. Well, the end result is that he was using vice grips on the fuel selector shaft for lack of a knob, and during the accident inspection, the FAA found a vice grip attached to a broken shaft, which the shaft was still in the main position - being out of fuel. When he ran out of fuel, most likely he reached back over his shoulder to switch to reserve and snapped the selector shaft. Fate is the Hunter. I like the idea of assuming 1/4 is E in the situation you had. Better safe than sorry.

To the OP. Heet is used on gasoline engines but not in diesel or 2-stroke. It is 100% methanol, which absorbs water. Several other brands use Isopropyl alcohol instead. If you have some 91% alcohol around, use a small amount - like a half cup etc., and it will act as a gas fuel line dryer if there is just a little water in the fuel. I ALWAYS start with the assumption that water is a high possibility culprit. It isn't the only one, but if the problem starts suddenly without mechanical noises, it is an inexpensive place to begin. On two strokes I usually assume that the diaphragm in the carb or fuel pump has been affected by ethanol or other chemicals in the fuel. I have had fixed jets unscrew and fall out - that one can be a puzzler.


#40

A

Auto Doc's

Auto Doc - interesting read. One has to wonder how does someone get multiple plastic baggies in the fuel tank except by sabotage? I know friends who have pulled tee shirts and socks out of gasoline tanks in collector cars when restoring them.

Rev-B - also an interesting read. John Denver crashed and died when he ran out of fuel on the main tank. The kit builder put the fuel selector over the pilot's shoulder instead of the recommended lower position on the floor or wing root. Denver never did anything with that, surprising because his father was an Air Force officer who flew, so Denver grew up knowing risks of flying. I say that because my dad was a career USCG SARS pilot and officer, and I know the many stories of his experiences of how easily things can go south to the unsuspecting / unprepared. Denver's fuel was low when he took off, someway inebriated, telling the FBO that he had enough fuel with his reserves to make the short trip home. Well, the end result is that he was using vice grips on the fuel selector shaft for lack of a knob, and during the accident inspection, the FAA found a vice grip attached to a broken shaft, which the shaft was still in the main position - being out of fuel. When he ran out of fuel, most likely he reached back over his shoulder to switch to reserve and snapped the selector shaft. Fate is the Hunter. I like the idea of assuming 1/4 is E in the situation you had. Better safe than sorry.

To the OP. Heet is used on gasoline engines but not in diesel or 2-stroke. It is 100% methanol, which absorbs water. Several other brands use Isopropyl alcohol instead. If you have some 91% alcohol around, use a small amount - like a half cup etc., and it will act as a gas fuel line dryer if there is just a little water in the fuel. I ALWAYS start with the assumption that water is a high possibility culprit. It isn't the only one, but if the problem starts suddenly without mechanical noises, it is an inexpensive place to begin. On two strokes I usually assume that the diaphragm in the carb or fuel pump has been affected by ethanol or other chemicals in the fuel. I have had fixed jets unscrew and fall out - that one can be a puzzler.
Hi sgkent,

It's known around here (in South Texas) as unemployed, past prison records, no steady job, "will work for food" and low (cash only) wage people who can drive anything with gears. Hay hauler trucks do not have to run DOT stickers; they just run Texas exempt farm tags.

The drivers work all kinds of crazy hours night and day, so when fueling up at a truck stop or gas station, they eat junk food on the run. The ones who feel slighted by the operation owner quietly sabotage the trucks with stupid tricks like plastic bags in the fuel tanks every now and then.

Fortunately, I stopped taking on that kind of HD work recently. These days I try to stick more with small engine lawn equipment, ATV's and Kawasaki mules or JD Gators.


#41

G

gregjo1948

I have a new Z325E Zero turn JD mower. Bought 2 months ago. 30 hours on it. Mowing today and when I disengaged the mower blades it started surging, like moving the throttle up and down. When a load is put on it, like mowing it does not surge. I cleaned my 5 gallon gas can, went to a different gas station frilled it up, came back, disconnected fuel line from mower gas tank, installed new gas filter, put gas line into gas can a couple inches below gas level, started the mower ran it 10 minutes and it still surged. It is under warranty, so I called the dealer that would be working on it. First thing they said was bad gas. I filled up 3- 5 gallon cans 2 weeks ago and used one can and no problem till today.
Spring tension on governor is slightly off.


#42

J

Jughead

Gumout


#43

StarTech

StarTech

Come on guys read the whole dang thread. JD said it was water in the fuel on in post 30. Most likely in the carburetor fuel bowl. Doesn't take all that much either nor does it takes that much in the fuel tank as water seeks the lowest point and stirs up during vibrations. The real for water is to clean the whole fuel system not just part of it.

Note these carbs are on the lean side in the first place so it doesn't take much to screw up the running.


#44

mpqualdie

mpqualdie

I have a new Z325E Zero turn JD mower. Bought 2 months ago. 30 hours on it. Mowing today and when I disengaged the mower blades it started surging, like moving the throttle up and down. When a load is put on it, like mowing it does not surge. I cleaned my 5 gallon gas can, went to a different gas station frilled it up, came back, disconnected fuel line from mower gas tank, installed new gas filter, put gas line into gas can a couple inches below gas level, started the mower ran it 10 minutes and it still surged. It is under warranty, so I called the dealer that would be working on it. First thing they said was bad gas. I filled up 3- 5 gallon cans 2 weeks ago and used one can and no problem till today.
My thought is,, if it runs fine when they are engaged but surges up and down when disengaged it isn't a fuel problem. The clutch to engage the blades is most likely a electrical clutch. It is possible there is something wrong with the clutch or the harness. I repaired a Cub Cadet one time where something struck the clutch and damaged the wire harness to it making it short out. It kept killing the motor and then catching back on over and over. So it was like turning the key off, then back on before it completely stalled.
On the fuel note, you should only be using "non-ethenol" gas.


#45

mpqualdie

mpqualdie

Come on guys read the whole dang thread. JD said it was water in the fuel on in post 30. Most likely in the carburetor fuel bowl. Doesn't take all that much either nor does it takes that much in the fuel tank as water seeks the lowest point and stirs up during vibrations. The real for water is to clean the whole fuel system not just part of it.

Note these carbs are on the lean side in the first place so it doesn't take much to screw up the running.
Then why would it run good when the blades are engaged, but not when they are off?


#46

StarTech

StarTech

Look ethanol fuel use is Okay. I been using it for a very long in all my equipment.
Then why would it run good when the blades are engaged, but not when they are off?
Because these engines runs off the idle ports when off load [Called high idle mode]; therefore, any restriction the idle mix system will cause them to surge. These engines only uses the main jet when loaded by the deck.

I even had to repair one Nikki clone where the manufacture put too small of idle mixture jet. Even though the carburetor had an idle mixture adjustment screw the jet was simply too restrictive and prevent the screw from enriching the mixture.


#47

S

spetrilli

I have a new Z325E Zero turn JD mower. Bought 2 months ago. 30 hours on it. Mowing today and when I disengaged the mower blades it started surging, like moving the throttle up and down. When a load is put on it, like mowing it does not surge. I cleaned my 5 gallon gas can, went to a different gas station frilled it up, came back, disconnected fuel line from mower gas tank, installed new gas filter, put gas line into gas can a couple inches below gas level, started the mower ran it 10 minutes and it still surged. It is under warranty, so I called the dealer that would be working on it. First thing they said was bad gas. I filled up 3- 5 gallon cans 2 weeks ago and used one can and no problem till today.
I use nothing but ethanol free premium in all my small engines, plus I put 5 to 8 oz of seafoam in every 5 gallon fuel container before I fill it.

I got tired of rebuilding and/or replacing carburetors on my equipment due to the negative accumulating effects of ethanol blended fuel on carburetor based engines.

E10 or E15 may be fine for fuel injected engines, but is a death sentence for carburetors… period!!!


#48

O

outdoorpowermike

Must remove carb and in ultrasonic cleaner, remove the air mixture screw also so after 15 minutes of cleaning use compressor to blow out all ports. Replace all intake gaskets or seals. This should fix surging problem, and adjust mixture screw at idle if needed.


#49

R

RevB

I use nothing but ethanol free premium in all my small engines, plus I put 5 to 8 oz of seafoam in every 5 gallon fuel container before I fill it.

I got tired of rebuilding and/or replacing carburetors on my equipment due to the negative accumulating effects of ethanol blended fuel on carburetor based engines.

E10 or E15 may be fine for fuel injected engines, but is a death sentence for carburetors… period!!!
Bullshit.


#50

R

RevB

Bad Gas is the standard when they have no clue . .Put Champion plugs in it .
Champion plugs are the standard answer when they have no clue. 🤔


#51

R

Rednec

Then why would it run good when the blades are engaged, but not when they are off?
Don't know that this will help you but many Honda walk behind mowers have the same problem if they have a blade clutch on them. With the blades not engaged they will set there and surge constantly. Then when you engage the blades it will smooth out and run great. The reasoning is that when you put a load on the engine it will pull more fuel into the engine so therefore it smooths out. Usually you can clean the pilot jet on the carb and correct this problem. The pilot jet is so small it doesn't take but a spec of foreign material to plug it partially up and cause this problem. I hope P&K hit the nail on the head and fixed your problem. I live in MWC so not that far from you. Good luck.


#52

T

theoldwizard1

Usually you can clean the pilot jet on the carb and correct this problem. The pilot jet is so small it doesn't take but a spec of foreign material to plug it partially up and cause this problem.
TRUE ! Almost all surging problems are cause by the pilot jet.

Depending on the size of the engine, you may or may NOT be able to clean it with one of the fine wires in a carburetor jet cleaner kit. If not, you need a set of #60 - #80 drill bits and a pin vice. Start small. like a #78 or #76.

I had to use a #76 on a genuine Honda GX160 just last week !


#53

J

Johner

I have a new Z325E Zero turn JD mower. Bought 2 months ago. 30 hours on it. Mowing today and when I disengaged the mower blades it started surging, like moving the throttle up and down. When a load is put on it, like mowing it does not surge. I cleaned my 5 gallon gas can, went to a different gas station frilled it up, came back, disconnected fuel line from mower gas tank, installed new gas filter, put gas line into gas can a couple inches below gas level, started the mower ran it 10 minutes and it still surged. It is under warranty, so I called the dealer that would be working on it. First thing they said was bad gas. I filled up 3- 5 gallon cans 2 weeks ago and used one can and no problem till today.
Most fuel problems will vanish if you use a fuel conditioner added when you fill a new can. I do this all year long with a marine grade conditioner. A few penny's at this point will lesson the amount of aspirin needed.


#54

R

RevB

Don't know that this will help you but many Honda walk behind mowers have the same problem if they have a blade clutch on them. With the blades not engaged they will set there and surge constantly. Then when you engage the blades it will smooth out and run great. The reasoning is that when you put a load on the engine it will pull more fuel into the engine so therefore it smooths out. Usually you can clean the pilot jet on the carb and correct this problem. The pilot jet is so small it doesn't take but a spec of foreign material to plug it partially up and cause this problem. I hope P&K hit the nail on the head and fixed your problem. I live in MWC so not that far from you. Good luck.
That load compensation only occurs because the governor opens the throttle plate increasing intake airflow which lowers the intake pressure and the atmosphere pushes more fuel thru the orifice.


#55

T

The Specialist

That load compensation only occurs because the governor opens the throttle plate increasing intake airflow which lowers the pressure and the atmosphere pushes more fuel thru the orifice.
Hi. I read your problem of the surge, but with all the chatter, I don’t know if you have fixed it. When you stated that you could hear popping coming through the exhaust, your problem is that you don’t have enough clearance on your intake valve. The intake valve is staying slightly open and the fuel/air mixture is going back and fourth in the pipe between the cylinder and carb. This is common with new engines and it needs a simple adjustment. I’m guessing that you have a briggs engine. If you need instructions-reply. I’m one of the top technicians in Canada and the United Kingdom.


#56

M

macdoesit

I have never used ethanol in anything. When I took it into JD it was surging and had a low volume very faint popping sound. I just mowed 2 acres of my 5 and no surging at all, but the very low volume popping has come back. Monday I will take it back to JD, unless it is a simple fix and someone can tell me how to do it, as I don't want to void the warranty. 200 hundred hours or 3 years.


#57

M

macdoesit

Hi. I read your problem of the surge, but with all the chatter, I don’t know if you have fixed it. When you stated that you could hear popping coming through the exhaust, your problem is that you don’t have enough clearance on your intake valve. The intake valve is staying slightly open and the fuel/air mixture is going back and fourth in the pipe between the cylinder and carb. This is common with new engines and it needs a simple adjustment. I’m guessing that you have a briggs engine. If you need instructions-reply. I’m one of the top technicians in Canada and the United Kingdom.
Yes B&S 24hp. Instructions would be great. Thank you.


#58

T

The Specialist

Yes B&S 24hp. Instructions would be great. Thank you.


#59

T

The Specialist

Ok. As you have 2 cylinders, you have to do each one separately.You will need a .005 feeler gauge.Remove both spark plugs. Remove both valve covers. Remove the plastic top shroud so you can turn the flywheel by hand.Take a screw driver that is fairly long and put it in the first spark plug hole and with watching the valves rotate the engine with your hand. You will see the rocker arm push on the valves. So there are 4 strokes to an engine, which is intake, compression, power and exhaust. You want that cylinder to be between the compression and power stroke. So you will see the top valve push down, and the piston will be moving down, the the piston will start to move up, and the intake valve will close. Bring the piston to the top, and just rotate it enough that it just starts to go down. Take your feeler gauge and it should slide in between the valve and the rocker arm. If it doesn’t, loosen off the 10mm nut , while holding the 14mm rocker nut. Rotate the 14mm one just slightly counter clockwise and tighten the 10mm lock nut. Do this until the feeler gauge slides in. Do the second side. Once you have done this, put the valve covers back on, the sparks plugs back in, and for safety, I’m supposed to say put the shroud back on. But what I do is make sure that nothing is around the flywheel (wires etc) and I will test run it to make sure the valves are not clacking. If the engine sounds perfect, I put the shroud back on. Email me direct at dvata@yahoo.com if you need further help


#60

T

The Specialist

Ok. As you have 2 cylinders, you have to do each one separately.You will need a .005 feeler gauge.Remove both spark plugs. Remove both valve covers. Remove the plastic top shroud so you can turn the flywheel by hand.Take a screw driver that is fairly long and put it in the first spark plug hole and with watching the valves rotate the engine with your hand. You will see the rocker arm push on the valves. So there are 4 strokes to an engine, which is intake, compression, power and exhaust. You want that cylinder to be between the compression and power stroke. So you will see the top valve push down, and the piston will be moving down, the the piston will start to move up, and the intake valve will close. Bring the piston to the top, and just rotate it enough that it just starts to go down. Take your feeler gauge and it should slide in between the valve and the rocker arm. If it doesn’t, loosen off the 10mm nut , while holding the 14mm rocker nut. Rotate the 14mm one just slightly counter clockwise and tighten the 10mm lock nut. Do this until the feeler gauge slides in. Do the second side. Once you have done this, put the valve covers back on, the sparks plugs back in, and for safety, I’m supposed to say put the shroud back on. But what I do is make sure that nothing is around the flywheel (wires etc) and I will test run it to make sure the valves are not clacking. If the engine sounds perfect, I put the shroud back on. Email me direct at dvata@yahoo.com if you need further help
You will do this with both valves at the same time


#61

Wazza65

Wazza65

I have a new Z325E Zero turn JD mower. Bought 2 months ago. 30 hours on it. Mowing today and when I disengaged the mower blades it started surging, like moving the throttle up and down. When a load is put on it, like mowing it does not surge. I cleaned my 5 gallon gas can, went to a different gas station frilled it up, came back, disconnected fuel line from mower gas tank, installed new gas filter, put gas line into gas can a couple inches below gas level, started the mower ran it 10 minutes and it still surged. It is under warranty, so I called the dealer that would be working on it. First thing they said was bad gas. I filled up 3- 5 gallon cans 2 weeks ago and used one can and no problem till today.
It sounds like the pilot (idle) jet is partially blocked. The dealer needs to remove and clean the carburettor. It's a very common fault. Sometimes the jet needs enlarging ever so slightly.


#62

R

RevB

I have never used ethanol in anything. When I took it into JD it was surging and had a low volume very faint popping sound. I just mowed 2 acres of my 5 and no surging at all, but the very low volume popping has come back. Monday I will take it back to JD, unless it is a simple fix and someone can tell me how to do it, as I don't want to void the warranty. 200 hundred hours or 3 years.
Now where did the "popping" come from? Wasn't ever mentioned until now.
I'm right over by the airport. Just sayin'.


#63

T

Timtoo

Now where did the "popping" come from? Wasn't ever mentioned until now.
I'm right over by the airport. Just sayin'.
Popping mentioned on first page.


#64

M

mechanicmd

I have a new Z325E Zero turn JD mower. Bought 2 months ago. 30 hours on it. Mowing today and when I disengaged the mower blades it started surging, like moving the throttle up and down. When a load is put on it, like mowing it does not surge. I cleaned my 5 gallon gas can, went to a different gas station frilled it up, came back, disconnected fuel line from mower gas tank, installed new gas filter, put gas line into gas can a couple inches below gas level, started the mower ran it 10 minutes and it still surged. It is under warranty, so I called the dealer that would be working on it. First thing they said was bad gas. I filled up 3- 5 gallon cans 2 weeks ago and used one can and no problem till today.
Hi, You and everyone else are going to say I'm wrong but I read somewhere if you install the wrong air filter on these engines they will surge. It seems there are two air filters that look similar but one has more pleats in the filter. Just stating what I read. good luck


#65

R

RevB

Popping mentioned on first page.
Ah ha....missed it....👍


#66

M

macdoesit

Ok. As you have 2 cylinders, you have to do each one separately.You will need a .005 feeler gauge.Remove both spark plugs. Remove both valve covers. Remove the plastic top shroud so you can turn the flywheel by hand.Take a screw driver that is fairly long and put it in the first spark plug hole and with watching the valves rotate the engine with your hand. You will see the rocker arm push on the valves. So there are 4 strokes to an engine, which is intake, compression, power and exhaust. You want that cylinder to be between the compression and power stroke. So you will see the top valve push down, and the piston will be moving down, the the piston will start to move up, and the intake valve will close. Bring the piston to the top, and just rotate it enough that it just starts to go down. Take your feeler gauge and it should slide in between the valve and the rocker arm. If it doesn’t, loosen off the 10mm nut , while holding the 14mm rocker nut. Rotate the 14mm one just slightly counter clockwise and tighten the 10mm lock nut. Do this until the feeler gauge slides in. Do the second side. Once you have done this, put the valve covers back on, the sparks plugs back in, and for safety, I’m supposed to say put the shroud back on. But what I do is make sure that nothing is around the flywheel (wires etc) and I will test run it to make sure the valves are not clacking. If the engine sounds perfect, I put the shroud back on. Email me direct at dvata@yahoo.com if you need further help
Thank you, if I have any problem, I will email you.


#67

M

macdoesit

No surging since back from JD. Popping stopped on its own. Running good so far.


#68

M

macdoesit

Mowed 5 acres yesterday, mower ran great.


#69

M

macdoesit

Thank you, if I have any problem, I will email you.
Thank you again for the valuable info. Just sent you an email.


#70

shootinsteel

shootinsteel

When you get it fixed let us know what the problem was and did Lowes take care of it for you.


#71

M

macdoesit

When you get it fixed let us know what the problem was and did Lowes take care of it for you.
I took it to JD, they said there was water in gas. They fixed it runs great. Water not under warranty.


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