TSX Carburetor Flooding

[LittleMo]

This is for those searching for a possible answer to the problem of massive flooding in Marvel Schebler TSX carburetors. It is a test that I believe should always be made before final assembly of these carbs. Your float may be touching the bowl at some point. Here is how to easily find out.

Open up the carb and dry it out. Remove the venturi and power needle screw. Put some tape on both sides in the bottom of the bowl opposite the pivot hinge so that the float does not touch the bottom. Then put some tape in the bowl where the pivot pin could touch the bowl. Put some small pieces of heat shrink tubing next to the head on the screws which hold the bowl together and heat them. Now put the carburetor together, including the gasket and without the venturi, but don't completely turn down the screws. The bottom of the carb is now electrically isolated from the top. Take a DMM meter with a continuity setting and connect one lead to the top, and one lead to the bottom of the carb. Since these carbs have a brass float and it is connected to the top, any continuity between top and bottom, when you hold the carb together and move it around, shows that the float is touching the bowl. Tilting the carb while tells you which side is touching. Carefully bending the pivot hinge attached to the top of the carb can twist the float so that it no longer touches the bowl.

 

[Ol 54']

Would that carb. By chance go to an Oliver tractor? I rebuilt a TSX Carb. last summer for my Oliver 55, it runs real good. I like the veneers calipers, old school. I wouldn't know what spec. tooling steel you need. I do know that is some dam hard steel.

 

[560Dennis]

Test needle and seat for float height ,leak test float (cold float into hot water ) look for air bubbles , clean fuel supply just to start as
mentioned look at the resource header in articles , could be an article on that carburetor

 

[UncleTom]

I do a few small engine carbs and i did one Marvel Schebler carb for my brother that flooded bad. It was a 4 cylinder chevy engine from a windrower that was transplanted onto a big metal shears. The carb flooded and i didnt have parts so i took the carb apart and cleaned it. I used a Q-tip and brake kleen in a drill and cleaned the brass seat. It stopped flooding and is still running today. Yes i needed a new needle and seat but didnt have one and wasnt going to wait.

 

[showcrop]

That procedure could be good for verification after the much quicker test of visually observing gas level in bowl. This is done by replacing the bowl drain with a barbed adapter with a six inch length of vinyl tubing held vertically next to the bowl. Watch the level as you start and run it. Massive flooding never happens with these carbs. It is almost always just gravity pulling the gas in the carburetor back down when it doesn't start.

 

[LittleMo]

Ole 54' It's just a way of eliminating the possibility of the float even touching the bowl. The tractor, as my handle implies, is an MM. It is a 70 hp M5. I grew up near the MM Minneapolis factory. I now live in Northern Minnesota, and I bought the tractor and a 7ft 3pt snowblower to clear a long open driveway. I wanted something big enough to run a sizable snowblower. I hoped to use it if we got a lot of snow, thankfully, we haven't (knock on wood). I am no fan of big hard drifts.

My opinion of the TSX795 carb on this tractor is the same opinion that a Klingon has about Tribbles, and yes, I am old enough to have seen it first run. So I am old school as well. I have never seen a carb on an engine even with a fuel pump flood like this. It's a good thing it is an updraft.

The carb flooded some when I got the tractor, so I replaced the float valve and seat and the gaskets of course. I checked the float height and the buoyancy of the float, in hot water, too. Put it together: it still flooded. Had it apart many times, going down the list of possibilities found online. It is outside, so I go out and get the carb, dry it out, and bring it in to work on it when it is cold, and put it back on and wait to try to start the tractor when it is warmer. Nothing like handling that iron when it is -10, and better yet, getting gas on your hands at that temp dumping the carb.

When I put the carb back, I let it stand with the gas petcock open for days to see if it will leak; no leaks. When I try to start the tractor it fires immediately, runs for a few seconds, and then dies from flooding. Air intake full of gas, pouring out when I remove it, and continuing to flow out after the engine stops. Hence my special interest in whether the float is hung up on the bowl.

Bought another kit, including a new float (not that I see anything wrong with the float, float valve, or seat), assembled the carb today. Time will tell. Too cold next week. Thanks to you all for your suggestions.

 

[wore out]

Ole 54' It's just a way of eliminating the possibility of the float even touching the bowl. The tractor, as my handle implies, is an MM. It is a 70 hp M5. I grew up near the MM Minneapolis factory. I now live in Northern Minnesota, and I bought the tractor and a 7ft 3pt snowblower to clear a long open driveway. I wanted something big enough to run a sizable snowblower. I hoped to use it if we got a lot of snow, thankfully, we haven't (knock on wood). I am no fan of big hard drifts.

My opinion of the TSX795 carb on this tractor is the same opinion that a Klingon has about Tribbles, and yes, I am old enough to have seen it first run. So I am old school as well. I have never seen a carb on an engine even with a fuel pump flood like this. It's a good thing it is an updraft.

The carb flooded some when I got the tractor, so I replaced the float valve and seat and the gaskets of course. I checked the float height and the buoyancy of the float, in hot water, too. Put it together: it still flooded. Had it apart many times, going down the list of possibilities found online. It is outside, so I go out and get the carb, dry it out, and bring it in to work on it when it is cold, and put it back on and wait to try to start the tractor when it is warmer. Nothing like handling that iron when it is -10, and better yet, getting gas on your hands at that temp dumping the carb.

When I put the carb back, I let it stand with the gas petcock open for days to see if it will leak; no leaks. When I try to start the tractor it fires immediately, runs for a few seconds, and then dies from flooding. Air intake full of gas, pouring out when I remove it, and continuing to flow out after the engine stops. Hence my special interest in whether the float is hung up on the bowl.

Bought another kit, including a new float (not that I see anything wrong with the float, float valve, or seat), assembled the carb today. Time will tell. Too cold next week. Thanks to you all for your suggestions.

Despite your bad experiences with this carb the TSX carbs are darned good units, and used with great success on a wide variety of engines.

Either you are overlooking something or there's an odd issue/flaw with your carb.

 

[Brian G. NY]

Despite your bad experiences with this carb the TSX carbs are darned good units, and used with great success on a wide variety of engines.

Either you are overlooking something or there's an odd issue/flaw with your carb.

Times two...."probably" better than Zenith....at least as far as ease of working on is concerned..

 

[rustred]

Ole 54' It's just a way of eliminating the possibility of the float even touching the bowl. The tractor, as my handle implies, is an MM. It is a 70 hp M5. I grew up near the MM Minneapolis factory. I now live in Northern Minnesota, and I bought the tractor and a 7ft 3pt snowblower to clear a long open driveway. I wanted something big enough to run a sizable snowblower. I hoped to use it if we got a lot of snow, thankfully, we haven't (knock on wood). I am no fan of big hard drifts.

My opinion of the TSX795 carb on this tractor is the same opinion that a Klingon has about Tribbles, and yes, I am old enough to have seen it first run. So I am old school as well. I have never seen a carb on an engine even with a fuel pump flood like this. It's a good thing it is an updraft.

The carb flooded some when I got the tractor, so I replaced the float valve and seat and the gaskets of course. I checked the float height and the buoyancy of the float, in hot water, too. Put it together: it still flooded. Had it apart many times, going down the list of possibilities found online. It is outside, so I go out and get the carb, dry it out, and bring it in to work on it when it is cold, and put it back on and wait to try to start the tractor when it is warmer. Nothing like handling that iron when it is -10, and better yet, getting gas on your hands at that temp dumping the carb.

When I put the carb back, I let it stand with the gas petcock open for days to see if it will leak; no leaks. When I try to start the tractor it fires immediately, runs for a few seconds, and then dies from flooding. Air intake full of gas, pouring out when I remove it, and continuing to flow out after the engine stops. Hence my special interest in whether the float is hung up on the bowl.

Bought another kit, including a new float (not that I see anything wrong with the float, float valve, or seat), assembled the carb today. Time will tell. Too cold next week. Thanks to you all for your suggestions.

If it’s flooding , it will be flooding as soon as the gas is turned on. Not sit a day till u start it. U got something going on there. It don’t take kits to make a carburator work. If the float and needle and seat is good. There is nothing else to it. I make my gaskets. Have u checked the float level and float drop ?

 

[showcrop]

Ole 54' It's just a way of eliminating the possibility of the float even touching the bowl. The tractor, as my handle implies, is an MM. It is a 70 hp M5. I grew up near the MM Minneapolis factory. I now live in Northern Minnesota, and I bought the tractor and a 7ft 3pt snowblower to clear a long open driveway. I wanted something big enough to run a sizable snowblower. I hoped to use it if we got a lot of snow, thankfully, we haven't (knock on wood). I am no fan of big hard drifts.

My opinion of the TSX795 carb on this tractor is the same opinion that a Klingon has about Tribbles, and yes, I am old enough to have seen it first run. So I am old school as well. I have never seen a carb on an engine even with a fuel pump flood like this. It's a good thing it is an updraft.

The carb flooded some when I got the tractor, so I replaced the float valve and seat and the gaskets of course. I checked the float height and the buoyancy of the float, in hot water, too. Put it together: it still flooded. Had it apart many times, going down the list of possibilities found online. It is outside, so I go out and get the carb, dry it out, and bring it in to work on it when it is cold, and put it back on and wait to try to start the tractor when it is warmer. Nothing like handling that iron when it is -10, and better yet, getting gas on your hands at that temp dumping the carb.

When I put the carb back, I let it stand with the gas petcock open for days to see if it will leak; no leaks. When I try to start the tractor it fires immediately, runs for a few seconds, and then dies from flooding. Air intake full of gas, pouring out when I remove it, and continuing to flow out after the engine stops. Hence my special interest in whether the float is hung up on the bowl.

Bought another kit, including a new float (not that I see anything wrong with the float, float valve, or seat), assembled the carb today. Time will tell. Too cold next week. Thanks to you all for your suggestions.

your carb is NOT flooding. It is simply the gas in the manifold being brought back down by gravity because it didn't start. Updraft carbs don't flood.

 

[LittleMo]

Weather was not as cold as predicted, about 0 today, so I put the carb with the new kit on; same results. Thanks showcrop, but the tractor does start and runs on all cylinders. It quits when it gets too much gas from what I call carb flooding, and belches rich smoke when it quits. Then it won't restart. The carb then continues to drip, and if I didn't remove the fitting and plug the fuel line I would eventually lose all the gas in the tank.

Like I said before, the valve seats itself properly as it initially gets filled, and will stand for days without leaking. But after running, even a little bit, it leaks and keeps leaking. The valve evidently doesn't reseat itself at all. Float new, at proper level, not binding, not even touching the bowl, needle and seat new, needle free to move. Gas tank clean. No visible sediment in sediment bowl. How can something so simple not work. I guess I will have to wait for warm days and keep on repeating the cycle, hoping it will eventually find a way to reseat itself.

Thanks to all of you for your comments.

 

[showcrop]

Weather was not as cold as predicted, about 0 today, so I put the carb with the new kit on; same results. Thanks showcrop, but the tractor does start and runs on all cylinders. It quits when it gets too much gas from what I call carb flooding, and belches rich smoke when it quits. Then it won't restart. The carb then continues to drip, and if I didn't remove the fitting and plug the fuel line I would eventually lose all the gas in the tank.

Like I said before, the valve seats itself properly as it initially gets filled, and will stand for days without leaking. But after running, even a little bit, it leaks and keeps leaking. The valve evidently doesn't reseat itself at all. Float new, at proper level, not binding, not even touching the bowl, needle and seat new, needle free to move. Gas tank clean. No visible sediment in sediment bowl. How can something so simple not work. I guess I will have to wait for warm days and keep on repeating the cycle, hoping it will eventually find a way to reseat itself.

Thanks to all of you for your comments.

Sounds like an ignition problem.

 

[teddy52food]

Are you sure the choke is open?

 

[scootergmc]

Just so I understand- if you go out to the tractor right now and turn on the fuel, it will flow from the carburetor? If fuel flows with the tractor off it's not an ignition problem.

Have you run the tractor off an independent tank hooked directly to the carb? Does the problem continue? Did you clean the entire fuel system and install a new fuel line from the strainer to the carb? How did you measure the float height? Did you measure 1/4" upon installation? Did you then verify with a clear tube after reassembly and flow? The most obvious solution in your case is float height.

Assuming all that has been done, I have seen one tractor carburetor in my life whereby someone had messed with a float (misadjusted and bent up) that it would drop the needle and allow the bowl to fill but would ever so slightly cause the needle to bind upon attempt to return to the seat. I don't think that's happening in your case since you said you have a new float, needle, seat, etc.

Edit to add further: Did you check the bowl for warping? I've never ran into enough that it caused flooding, but when I rebuild carbs I like to make sure they're nice and flush.

 

[LittleMo]

Not an ignition problem. Being that I intended to use the tractor in the winter, I wanted it to have the best possible chance of starting. Wiring was bad when I got it, so I rewired it completely. Also new plugs, spark plug wires, cap, rotor, and points. The starter is a Delco replacement so it has the R S terminals. I decided to make use of the resistor terminal and I put a new coil with the external resistor on the tractor too, to ensure the best possible spark when starting.

When I started the tractor at 15 degrees temp, it started immediately. No excess cranking. Pushed the choke in as soon as possible. It ran well for about 10 seconds then died and belched rich smoke. I checked the air intake before starting and it was dry. After the engine stopped the intake hose was full of fuel. The fuel ran out and much more than could have been in the carb fell in my drain pan. I had to shut off the fuel to stop the flow.

As for the tank, it is like new inside. Since the sediment bowl leaked when I got the tractor, that is new too. There is no question that the fuel line is clean. I set float height at 1/4". Neither top, nor bottom, of the carb is warped. Besides, I sealed the gasket last time with the anaerobic stuff in case it wasn't sealing properly. Now I have to contend with that. I removed the carb again today and tomorrow after it dries I will take a look at how the valve closes under magnification.

I do not know if the fuel would start running again if turned the gas on. I usually remove the carb, and plug the fuel line because it drips with the fuel shut off. I suppose I should try that. I have not tried the manometer approach for checking the fuel level. I don't really want to try to open that 62 year old bowl drain for the first time if I can help it. I would also have to go and get a barbed fitting to try it.

If it isn't the carb, then the only candidate I can think of is the air filter, but I changed oil in that too.

Thanks!

 

[Jim.ME]

Not an ignition problem. Being that I intended to use the tractor in the winter, I wanted it to have the best possible chance of starting. Wiring was bad when I got it, so I rewired it completely. Also new plugs, spark plug wires, cap, rotor, and points. The starter is a Delco replacement so it has the R S terminals. I decided to make use of the resistor terminal and I put a new coil with the external resistor on the tractor too, to ensure the best possible spark when starting.

When I started the tractor at 15 degrees temp, it started immediately. No excess cranking. Pushed the choke in as soon as possible. It ran well for about 10 seconds then died and belched rich smoke. I checked the air intake before starting and it was dry. After the engine stopped the intake hose was full of fuel. The fuel ran out and much more than could have been in the carb fell in my drain pan. I had to shut off the fuel to stop the flow.

As for the tank, it is like new inside. Since the sediment bowl leaked when I got the tractor, that is new too. There is no question that the fuel line is clean. I set float height at 1/4". Neither top, nor bottom, of the carb is warped. Besides, I sealed the gasket last time with the anaerobic stuff in case it wasn't sealing properly. Now I have to contend with that. I removed the carb again today and tomorrow after it dries I will take a look at how the valve closes under magnification.

I do not know if the fuel would start running again if turned the gas on. I usually remove the carb, and plug the fuel line because it drips with the fuel shut off. I suppose I should try that. I have not tried the manometer approach for checking the fuel level. I don't really want to try to open that 62 year old bowl drain for the first time if I can help it. I would also have to go and get a barbed fitting to try it.

If it isn't the carb, then the only candidate I can think of is the air filter, but I changed oil in that too.

Thanks!

Dirty Oil isn’t the only thing that can happen to air cleaners. The intake tube of the air filter can get restricted or plugged. The mesh media the it has to pass through to leave the air cleaner can get restricted or plugged. Those things would simulate the choke being on. Remove the air hose connection from the carb inlet and try running it to see what happens.

 

[Mark-Ia]

Float full of gas? Have you immersed the float in a pan of hot water and check it for leaks? It will have air bubbles if it does

 

[teddy52food]

Not an ignition problem. Being that I intended to use the tractor in the winter, I wanted it to have the best possible chance of starting. Wiring was bad when I got it, so I rewired it completely. Also new plugs, spark plug wires, cap, rotor, and points. The starter is a Delco replacement so it has the R S terminals. I decided to make use of the resistor terminal and I put a new coil with the external resistor on the tractor too, to ensure the best possible spark when starting.

When I started the tractor at 15 degrees temp, it started immediately. No excess cranking. Pushed the choke in as soon as possible. It ran well for about 10 seconds then died and belched rich smoke. I checked the air intake before starting and it was dry. After the engine stopped the intake hose was full of fuel. The fuel ran out and much more than could have been in the carb fell in my drain pan. I had to shut off the fuel to stop the flow.

As for the tank, it is like new inside. Since the sediment bowl leaked when I got the tractor, that is new too. There is no question that the fuel line is clean. I set float height at 1/4". Neither top, nor bottom, of the carb is warped. Besides, I sealed the gasket last time with the anaerobic stuff in case it wasn't sealing properly. Now I have to contend with that. I removed the carb again today and tomorrow after it dries I will take a look at how the valve closes under magnification.

I do not know if the fuel would start running again if turned the gas on. I usually remove the carb, and plug the fuel line because it drips with the fuel shut off. I suppose I should try that. I have not tried the manometer approach for checking the fuel level. I don't really want to try to open that 62 year old bowl drain for the first time if I can help it. I would also have to go and get a barbed fitting to try it.

If it isn't the carb, then the only candidate I can think of is the air filter, but I changed oil in that too.

Thanks!

An easy test is to let the hose off & see what happens. I would think that is the problem!

 

[scootergmc]

I figured you were describing the condition without the intake attached. Eliminate the air source as a problem, and other external problems. Get rid of the gasket sealer. And the warpage can occur whereby the middle of the carb sits lower than the outer rims, but you said there's no warpage, so I'm assuming you've checked all that with an edge. Good luck.

I don't know why I put myself through the misery of online carb diagnosis, probably because I enjoy getting them right at home. The full story at the outset is always lacking, yet somehow I almost always get sucked into a black hole.

 

[LittleMo]

Hi scootergmc and all, everybody loves a mystery novel, and it is because not all the facts are known right away. It is the journey that is of interest. Don't let this stop you from getting involved, look at it as entertainment.

I am confident that I have found the solution, although it will take me days to be sure. I do not want to waste any more of your time and I apologize for the time I have wasted . The solution appears to be the air cleaner.

When I bought the tractor it ran well. There was no reason to suspect anything. It started having problems after it sat here for a while. But then, life is like that: things go well until they don't, then go bad suddenly, sometimes very bad. The air cleaner waited for me to get the tractor before it clogged up enough to cause problems. When I saw the fuel, I took it to be flooding, since the carb had never been touched, and it had over 60 years to wear on the float valve.

I should have noticed it right away. I blame it on having been raised in the city. I never worked on large machinery and in particular on anything with this kind of air filtration, except for a very old lawn mower, or two. Truth is, it has not been cleaned in many years, and the pre-cleaner was almost plugged. I'm sure I saw it at some point too, probably thinking the pre-cleaner was oiled foam instead of the hardware cloth it really is. That is what it looked like. The poor engine was just doing it's best as long as it could. It is a reminder to do regular maintenance. The previous owners didn't. I should have known that too, since they added water to the antifreeze when the radiator leaked. Who would do that in this part of the country?

Again, thanks to all of you for your time and consideration.