Pony Motor Wants More Fuel

[quote="tdow"]Howdy,

I became the proud owner of a D4 7U, good ol' 7U1195X about a month and a half ago. I bought it from a university near here who used it for pulling agricultural implements and snow plowing (you can see the attachments on the bottom of the blade that they put on for snow plowing). I think it sat for 6 years, and the guy who seems to have been in charge of it there was able to get it started without too much issue.

[img][IMG]http://www.acmoc.org/bb/attachment.php?attachmentid=77778&d=1536032793[/img][/IMG]

I bought it at an auction. My wife was with me, pregnant with kid #6. We agreed on a price and I blew right past that in a bidding war. I won it exactly after she walked up to me and said, "I really don't want this." It was awesome! I felt a little like throwing up, because at that moment my knowledge of heavy machinery was basically nothing. Since then, she's excicted to have it, and I need to put it to work on 40 acres of timbered land we just bought so that we can get better access to our building site (the first building will be a shop to work on more machines 😉 )

The sediment bowl filter and water separator were replaced some time ago with in inline fuel filter. I have the body of the original unit, but the glass had long been broken out, so I could choose to try to find a replacement if it makes any sense to bring it back to original.

The day I bought it we started it three times. The first two took 10-20 minutes of coaxing. I learned the fun trick of blowing into the fuel tank. The third time it just wouldn't start, until a couple hours later, when it did- easily. The main engine was running in probably less than two minutes. That first day once the pony motor was running it was able to easily start the main engine. Two weeks ago the pony was harder to start and it had trouble getting the main engine to run fast enough to start, but it did. I drove it around and knocked over a little tree. It made me feel like a better person 😊

So far when the pony has run, it needs to have the choke pulled most or all of the way out, and the throttle needs to be pulled all the way back, or the pony dies.

Two days ago, it just wasn't going to start (never did), so I checked the fuel lines. First, no gas flowing into the carb. I was getting enough gas into the fuel shutoff valve for it to leak, and it leaks enough to drain the tank between two weeks. I blew through the section of line from the filter to the fuel shutoff valve, which at first didn't budge, then a bunch of crud shot out. I sprayed a bunch of carb cleaner through that section to clean it, but it's still hard to blow through. Pretty much the same deal on the line from the shutoff valve to the carb: crud, and unimpressive flow after spraying it out.

I pulled the tank and brought home the shutoff valve as well. I figured if the system is gravity fed, and the valve is leaking at a level way below the carb, it's like feeding a straw with a hole in it so it needs some attention.

I am curious about the amount of flow through the inline filter, if that has has to be flowing freely enough to have gravity bring it down and back up to the carb. I put it on the tank after I had it out of the machine and let fuel run through it, and it varied from a trickle to a small stream, like my middle aged morning pee.

Then I realized after moving the gas tank a little bit, that the local mariachi band showed up and was trying to recruit me as their rhythm section, because there was enough sediment in that think that it shakes like a damn maraca. There seriously has to be a handful of grainy gunk in there. The inside of the tank is deeply pitted and rusted.

I took apart the fuel shutoff valve, and most of it looks okay, except the threaded piece connected to the petcock, on the inside where two circular portions are apparently meant to stop the flow of fuel, to the carb when fully closed, and to the outside when fully open. I expected to find some packing inside, but there was nothing to speak of except dirt- THAT THING WAS FILTHY!

I'm submitting my plan of action so you can tell me all of the ways in which I need to stop being stupid:

1. Get the rust out of the tank, probably with something like Evaporust, then coat the tank like the antique motorcycle guys do, probably with Redkote. I will use silicon to protect the threads of the drain plug, which is stuck at the moment.

2. At the filter- I had considered going from the tank, to an inline filter, installing a shut off valve just below that, then straight into the carb, which seems like the most efficient way to run (except for having to walk all they way around the
machine. I would rather go back to the original unit, and retain the shutoff valve on the left side of the machine. This will depend on me finding a new sediment bowl.
Question: will I get a better fuel flow from the original unit than the new inline filter?

3. Clean the shut off valve really well, and de rust the rusted part of the valve inside.
Question: is there supposed to be packing in there, and if so, what kind?

4. I'm not happy with the fuel lines. They still feel like the carotids of all my older male relatives with a propensity toward heart disease. I think I'm going to find a bicycle brake cable, fray one end, run the other end through each line,
chuck it in a drill, then pull the frayed end through with the drill going.

I'm hoping all that will clear the line from the tank to the carb, and that coating the tank will head off as much as I can in the way of keeping dirt out of the fuel system.

5. I haven't decided whether to remove and clean the carb. I want to, but my wife says not to mess with it. I figure I already have the fuel tank off, and I'm pretty convinced that if I don't clean it, it will be one of those deals where it will
start, but I still won't be able to run it without the choke engaged. That might even be optimistic based on the condition of everything up to that point, although I've been [I]mostly[I] able to start it so far. I would like it to just run like a
total champ. But she wants to see me doing actual work with it ASAP, and so do I, and she's usually right.

My goal is to have everything back together so I can start it this Sunday. I would appreciate any advice, and I will keep you posted on the outcome.

Also, I'm sorry I wrote you a damn novel. It's just what I do.[/quote]


Good morning,
Sounds like you have some pretty typical problems associated with these old Cats. Cleaning the pony fuel tank and lines along with the carb is probably going to help a lot with the starting issues.
Bill

[quote="tdow"]Howdy,

I became the proud owner of a D4 7U, good ol' 7U1195X about a month and a half ago. I bought it from a university near here who used it for pulling agricultural implements and snow plowing (you can see the attachments on the bottom of the blade that they put on for snow plowing). I think it sat for 6 years, and the guy who seems to have been in charge of it there was able to get it started without too much issue.

[img][IMG]http://www.acmoc.org/bb/attachment.php?attachmentid=77778&d=1536032793[/img][/IMG]

I bought it at an auction. My wife was with me, pregnant with kid #6. We agreed on a price and I blew right past that in a bidding war. I won it exactly after she walked up to me and said, "I really don't want this." It was awesome! I felt a little like throwing up, because at that moment my knowledge of heavy machinery was basically nothing. Since then, she's excicted to have it, and I need to put it to work on 40 acres of timbered land we just bought so that we can get better access to our building site (the first building will be a shop to work on more machines 😉 )

The sediment bowl filter and water separator were replaced some time ago with in inline fuel filter. I have the body of the original unit, but the glass had long been broken out, so I could choose to try to find a replacement if it makes any sense to bring it back to original.

The day I bought it we started it three times. The first two took 10-20 minutes of coaxing. I learned the fun trick of blowing into the fuel tank. The third time it just wouldn't start, until a couple hours later, when it did- easily. The main engine was running in probably less than two minutes. That first day once the pony motor was running it was able to easily start the main engine. Two weeks ago the pony was harder to start and it had trouble getting the main engine to run fast enough to start, but it did. I drove it around and knocked over a little tree. It made me feel like a better person 😊

So far when the pony has run, it needs to have the choke pulled most or all of the way out, and the throttle needs to be pulled all the way back, or the pony dies.

Two days ago, it just wasn't going to start (never did), so I checked the fuel lines. First, no gas flowing into the carb. I was getting enough gas into the fuel shutoff valve for it to leak, and it leaks enough to drain the tank between two weeks. I blew through the section of line from the filter to the fuel shutoff valve, which at first didn't budge, then a bunch of crud shot out. I sprayed a bunch of carb cleaner through that section to clean it, but it's still hard to blow through. Pretty much the same deal on the line from the shutoff valve to the carb: crud, and unimpressive flow after spraying it out.

I pulled the tank and brought home the shutoff valve as well. I figured if the system is gravity fed, and the valve is leaking at a level way below the carb, it's like feeding a straw with a hole in it so it needs some attention.

I am curious about the amount of flow through the inline filter, if that has has to be flowing freely enough to have gravity bring it down and back up to the carb. I put it on the tank after I had it out of the machine and let fuel run through it, and it varied from a trickle to a small stream, like my middle aged morning pee.

Then I realized after moving the gas tank a little bit, that the local mariachi band showed up and was trying to recruit me as their rhythm section, because there was enough sediment in that think that it shakes like a damn maraca. There seriously has to be a handful of grainy gunk in there. The inside of the tank is deeply pitted and rusted.

I took apart the fuel shutoff valve, and most of it looks okay, except the threaded piece connected to the petcock, on the inside where two circular portions are apparently meant to stop the flow of fuel, to the carb when fully closed, and to the outside when fully open. I expected to find some packing inside, but there was nothing to speak of except dirt- THAT THING WAS FILTHY!

I'm submitting my plan of action so you can tell me all of the ways in which I need to stop being stupid:

1. Get the rust out of the tank, probably with something like Evaporust, then coat the tank like the antique motorcycle guys do, probably with Redkote. I will use silicon to protect the threads of the drain plug, which is stuck at the moment.

2. At the filter- I had considered going from the tank, to an inline filter, installing a shut off valve just below that, then straight into the carb, which seems like the most efficient way to run (except for having to walk all they way around the
machine. I would rather go back to the original unit, and retain the shutoff valve on the left side of the machine. This will depend on me finding a new sediment bowl.
Question: will I get a better fuel flow from the original unit than the new inline filter?

3. Clean the shut off valve really well, and de rust the rusted part of the valve inside.
Question: is there supposed to be packing in there, and if so, what kind?

4. I'm not happy with the fuel lines. They still feel like the carotids of all my older male relatives with a propensity toward heart disease. I think I'm going to find a bicycle brake cable, fray one end, run the other end through each line,
chuck it in a drill, then pull the frayed end through with the drill going.

I'm hoping all that will clear the line from the tank to the carb, and that coating the tank will head off as much as I can in the way of keeping dirt out of the fuel system.

5. I haven't decided whether to remove and clean the carb. I want to, but my wife says not to mess with it. I figure I already have the fuel tank off, and I'm pretty convinced that if I don't clean it, it will be one of those deals where it will
start, but I still won't be able to run it without the choke engaged. That might even be optimistic based on the condition of everything up to that point, although I've been [I]mostly[I] able to start it so far. I would like it to just run like a
total champ. But she wants to see me doing actual work with it ASAP, and so do I, and she's usually right.

My goal is to have everything back together so I can start it this Sunday. I would appreciate any advice, and I will keep you posted on the outcome.

Also, I'm sorry I wrote you a damn novel. It's just what I do.[/quote]


Good morning,
Sounds like you have some pretty typical problems associated with these old Cats. Cleaning the pony fuel tank and lines along with the carb is probably going to help a lot with the starting issues.
Bill

Good plan:
1. Yes, clean the tank because otherwise it will continue to feed problems. I coated mine too but if you get it clean, keep it clean, and keep moisture out of it, it probably won't need any coating. Some folks put a dribble of two-stroke oil in the gasoline which will coat the tank and slow/stop the rust
2. Fuel flow from both should be a "flow", not a dribble. Inline filter may flow more than that but you don't need the extra. Your existing valve/sediment bowl will be sufficient. Pick up a new filter element and bowl gasket from Cat. The element screws into the center hole of the valve body inside the bowl. Cat also has the bowl new but it's steel. If you want glass, Florin Tractor has them new. Find Florin's details in the parts supply sticky on the main Discussion forum page
3. If you're talking about the shutoff valve on the left side of the tractor, just buy a new one from Cat. They're brass and obviously work like new
4. Good idea. The flexible cable trick is also useful in cleaning sediment out of the pony coolant passages. The crud collects at the bottom and can choke off all circulation leading to predictable results. Folks use a car speedo cable for that as the passages are larger
5. It's a good idea to clean the carb because then it will run properly and develop full power. The diesel will be harder to start in winter so you need full power from the pony. The trick with carb cleaning is to remove the lead plugs in the bottom of the bowl and using a small drill bit between your fingers, clean out the cross-passage on the bottom of the bowl. That passage chokes up forcing you to use the choke to pull fuel via another passage and it's not enough. If it doesn't idle well (after trying the idle screw adjustment and checking for vacuum leaks), there is an idle jet which looks like a brass plug just at the level of the throttle butterfly in the venturi when it's closed. That jet doesn't have a hole so much as a couple of notches in the side. At least one of those notches needs to be below the level of the butterfly when it's closed in order to see vacuum and thus pull idle fuel through. Inspect that and if you can't see the notches on the "down" side, you can very carefully punch the jet through into the venturi (make sure the butterfly is open to avoid damaging the jet) and then reinstall it from the outside with the notch in the correct down position. If the jet has two notches, choose the larger one to be down or if they're close together, have them both down when the butterfly is closed.
This is my example - https://www.youtube.com/watch?v=978GoUaR2yk&t=5s - needs a bit more tuning once it's installed back on the tractor but you get the idea.
You need a gasket set for the carb that you can also find from a supplier in the stickies.

Also, keep your wife happy by tow-starting the D4 if you need to. If you have a 4wd pickup with weight in the back, it's pretty easy. Drop a ton of something in there for some traction - put the D4 in fifth. Put your chain underneath the blade to keep it off the ground. You can probably pull on the blade if the rear clamps are in good shape. Or, park the D4 on a decent slope that ideally runs toward a road in case you don't get it started

just to get you going i would take the fuel line loose at a convenient spot and take compressed air and reverse blow back into the fuel tank with the cap off. then i would let the tank drain completely reconnect the fuel line with an inline fuel filter for a small engine. then i would fill the tank 1/4 full and retry. don't forget the small engine fuel filter to trap debris. you should be able to use some 5/15 fuel hose to jury rig it inline temporarily.

looks like your right final drive is seeping. mine was doing that so i adjusted the bearing and it stopped.

If you get the tank clean depending on local humidity you wouldn't need to coat it if you keep it full.

I put a short stand pipe inside of mine to keep the bottom gunk from clogging the hole.
Straight down to an automotive filter, then a shut off valve, then new line to carb.
You really need to SEARCH "Neil" who has done extensive overhaul and cleaning on those carbs!
Good Detailed reading!
Not always necessary to keep something that is a Workhorse original if a more realistic modern solution is available! 👍

Good plan:
1. Yes, clean the tank because otherwise it will continue to feed problems. I coated mine too but if you get it clean, keep it clean, and keep moisture out of it, it probably won't need any coating. Some folks put a dribble of two-stroke oil in the gasoline which will coat the tank and slow/stop the rust
2. Fuel flow from both should be a "flow", not a dribble. Inline filter may flow more than that but you don't need the extra. Your existing valve/sediment bowl will be sufficient. Pick up a new filter element and bowl gasket from Cat. The element screws into the center hole of the valve body inside the bowl. Cat also has the bowl new but it's steel. If you want glass, Florin Tractor has them new. Find Florin's details in the parts supply sticky on the main Discussion forum page
3. If you're talking about the shutoff valve on the left side of the tractor, just buy a new one from Cat. They're brass and obviously work like new
4. Good idea. The flexible cable trick is also useful in cleaning sediment out of the pony coolant passages. The crud collects at the bottom and can choke off all circulation leading to predictable results. Folks use a car speedo cable for that as the passages are larger
5. It's a good idea to clean the carb because then it will run properly and develop full power. The diesel will be harder to start in winter so you need full power from the pony. The trick with carb cleaning is to remove the lead plugs in the bottom of the bowl and using a small drill bit between your fingers, clean out the cross-passage on the bottom of the bowl. That passage chokes up forcing you to use the choke to pull fuel via another passage and it's not enough. If it doesn't idle well (after trying the idle screw adjustment and checking for vacuum leaks), there is an idle jet which looks like a brass plug just at the level of the throttle butterfly in the venturi when it's closed. That jet doesn't have a hole so much as a couple of notches in the side. At least one of those notches needs to be below the level of the butterfly when it's closed in order to see vacuum and thus pull idle fuel through. Inspect that and if you can't see the notches on the "down" side, you can very carefully punch the jet through into the venturi (make sure the butterfly is open to avoid damaging the jet) and then reinstall it from the outside with the notch in the correct down position. If the jet has two notches, choose the larger one to be down or if they're close together, have them both down when the butterfly is closed.
This is my example - https://www.youtube.com/watch?v=978GoUaR2yk&t=5s - needs a bit more tuning once it's installed back on the tractor but you get the idea.
You need a gasket set for the carb that you can also find from a supplier in the stickies.

Also, keep your wife happy by tow-starting the D4 if you need to. If you have a 4wd pickup with weight in the back, it's pretty easy. Drop a ton of something in there for some traction - put the D4 in fifth. Put your chain underneath the blade to keep it off the ground. You can probably pull on the blade if the rear clamps are in good shape. Or, park the D4 on a decent slope that ideally runs toward a road in case you don't get it started

looks like your right final drive is seeping. mine was doing that so i adjusted the bearing and it stopped.

Even if you want an after market online filter I would use a glass bowl first to check for condensation. Also I like to see the fuel swirl in the bowl when I turn it on to know that gas is getting down stream