Hope someone can help

[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.

 

[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.

 

[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.

 

[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.

 

[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.

 

[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.

 

[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.

 

[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.

 

[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.

 

[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.