53 Jubilee

[buickal]

I have posted previously about my problems getting my dads 53 Jubilee running. Basically, the tractor was hard to crank and ran poorly and the carb leaked fuel. Idle was bad, black smoke out the exhaust when running and ran terribly at all throttle positions. I have verified spark and compression and fuel to the carb and ensured I have good fuel. I am fairly certain that the issue is the carb. Had it rebuilt by a local tractor mechanic but didn’t help things. This has me thinking the carb has some issue where it’s not capable of being rebuilt.

I am to the point where I think I just want to buy a new carb and try that as a solution but I don’t want to buy a crappy Chinese carb. I see there is a Zenith replacement that is described as being improved and better designed. There are a couple of other options too. None of the replacement carbs are cheap and they can’t be returned so I want to make the right choice the first time. So given this, what carb is the one to get?

 

[Sean in PA]

Have you checked the compression?

 

[Sean in PA]

Also, someone reported good results with a US Made Zenith tha he bought from jhere no Yestrday's Tractors. Her's a link to that thread:

Link to thread on US made Zenith Carb

 

[Tim PloughNman Daley]

I have posted previously about my problems getting my dads 53 Jubilee running. Basically, the tractor was hard to crank and ran poorly and the carb leaked fuel. Idle was bad, black smoke out the exhaust when running and ran terribly at all throttle positions. I have verified spark and compression and fuel to the carb and ensured I have good fuel. I am fairly certain that the issue is the carb. Had it rebuilt by a local tractor mechanic but didn’t help things. This has me thinking the carb has some issue where it’s not capable of being rebuilt.

I am to the point where I think I just want to buy a new carb and try that as a solution but I don’t want to buy a crappy Chinese carb. I see there is a Zenith replacement that is described as being improved and better designed. There are a couple of other options too. None of the replacement carbs are cheap and they can’t be returned so I want to make the right choice the first time. So given this, what carb is the one to get?

Incorrect wiring account for 99.98% of all non-starting issues whether 6V or 12V. You don't tell us what you have to start with. 1st thing to test is the battery - take to a shop under load,then leave it disconnected while you verify wiring with your VOM. 2nd thing is to perform the Fuel Flow Test with a cold engine. You said, Carb ran poorly and leaked fuel, that ain't good ---- correct root cause problem B4 anything else. Do you really want to be running with a leaking fuel issue??? Local mechanic can be anything from shadetree backyard dudes to machine shop guys - don't mean a thing and each has his own ideas. ZENITH are good carbs but I'd hold off on a purchase for now. Is yours the OEM Marvel-Schebler TSX 428 Carb? I rebuild these in my sleep -email me. Adjusting the FORD/M-S carbs requires patience. Engine must be HOT, up to temp first. Jet Settings set to initial manual specs to start. Tweaks only at 1/8 to 1/4 turns at time and then WAIT until engine speed catches up. Must do this several times til right. GOV may have to be tweaked too. I've had basket case M/S carbs and have restored them to running OEM as good as new units so not buying it isn't capable of a rebuild. Contact me.

Tim Daley (MI)

 

[buickal]

Incorrect wiring account for 99.98% of all non-starting issues whether 6V or 12V. You don't tell us what you have to start with. 1st thing to test is the battery - take to a shop under load,then leave it disconnected while you verify wiring with your VOM. 2nd thing is to perform the Fuel Flow Test with a cold engine. You said, Carb ran poorly and leaked fuel, that ain't good ---- correct root cause problem B4 anything else. Do you really want to be running with a leaking fuel issue??? Local mechanic can be anything from shadetree backyard dudes to machine shop guys - don't mean a thing and each has his own ideas. ZENITH are good carbs but I'd hold off on a purchase for now. Is yours the OEM Marvel-Schebler TSX 428 Carb? I rebuild these in my sleep -email me. Adjusting the FORD/M-S carbs requires patience. Engine must be HOT, up to temp first. Jet Settings set to initial manual specs to start. Tweaks only at 1/8 to 1/4 turns at time and then WAIT until engine speed catches up. Must do this several times til right. GOV may have to be tweaked too. I've had basket case M/S carbs and have restored them to running OEM as good as new units so not buying it isn't capable of a rebuild. Contact me.

Tim Daley (MI)

The tractor started and ran….but horribly. The carb was rebuilt and it helped a little but still didn’t fix it. It almost seems like there is a crack or something where air is coming into the carb. I thought about getting some starting fluid and spraying around the outside to see if it impacts the idle. The carb still leaks fuel at the bottom where the nut on that carb is. My understanding is that’s normal but the amount should be a drip not a stream. That all got fixed with the rebuild but the rebuild did not fix how it runs. The guy who rebuilt it is a certified mechanic for big tractors and heavy equipment ( he has a truck and is mobile) but as you say….that may not mean anything.

The battery was new and the wiring is 12v and nothing changed with that so I didn’t think it would be the problem. Compression is solid like I mentioned.

I will contact you privately. More than happy to pay to get it rebuilt right and have someone who knows these carbs tell me if it’s not rebuildable. That can happen….not common but possible.

 

[old]

The tractor started and ran….but horribly. The carb was rebuilt and it helped a little but still didn’t fix it. It almost seems like there is a crack or something where air is coming into the carb. I thought about getting some starting fluid and spraying around the outside to see if it impacts the idle. The carb still leaks fuel at the bottom where the nut on that carb is. My understanding is that’s normal but the amount should be a drip not a stream. That all got fixed with the rebuild but the rebuild did not fix how it runs. The guy who rebuilt it is a certified mechanic for big tractors and heavy equipment ( he has a truck and is mobile) but as you say….that may not mean anything.

The battery was new and the wiring is 12v and nothing changed with that so I didn’t think it would be the problem. Compression is solid like I mentioned.

I will contact you privately. More than happy to pay to get it rebuilt right and have someone who knows these carbs tell me if it’s not rebuildable. That can happen….not common but possible.

Black smoke says it is running to rich so you have a float or main jet problem or an air cleaner problem

 

[Eman85]

"The carb still leaks fuel at the bottom where the nut on that carb is. My understanding is that’s normal but the amount should be a drip not a stream. That all got fixed with the rebuild but the rebuild did not fix how it runs."


From the comfort of my couch it sure sounds like you have carburetor problems. Most likely the basic carburetor is fine, just needs rebuilding and adjusting. Dripping gas is not acceptable or normal.

 

[40Mule]

Before you give up on it try boiling the carb. I learned this from Dad sixty years ago and is nothing more than suspending it in a pot with a piece of wire in water on the stove. Takes three or four times and you will know you are done when no more oil slick is on top of the water. You can then use a fine wire if you want to clean out passages. Not for plastic parts obviously. We never had carb spray and the store was too far away and it cost too much. I recently got a MF 50 running that had three new carb kits that were put in with this method. Tried plowing with it and it ran great and no problem since. Have also saw the incoming air passage on air cleaner closed down from chaff and oil where they ran poorly. Throttle shafts do wear in the body and cause air leaks.

 

[buickal]

Before you give up on it try boiling the carb. I learned this from Dad sixty years ago and is nothing more than suspending it in a pot with a piece of wire in water on the stove. Takes three or four times and you will know you are done when no more oil slick is on top of the water. You can then use a fine wire if you want to clean out passages. Not for plastic parts obviously. We never had carb spray and the store was too far away and it cost too much.

Now that’s a neat trick I’ve never heard before. Thanks.

 

[Jim L WA]

Eman85 made a good point about the air cleaner. Have you tried running it without the air cleaner? Also make sure the choke is actually open.
Air leaking in around the manifold or throttle shafts would make it run lean not rich.
Keep us up to-date.

 

[Tim PloughNman Daley]

Before you give up on it try boiling the carb. I learned this from Dad sixty years ago and is nothing more than suspending it in a pot with a piece of wire in water on the stove. Takes three or four times and you will know you are done when no more oil slick is on top of the water. You can then use a fine wire if you want to clean out passages. Not for plastic parts obviously. We never had carb spray and the store was too far away and it cost too much. I recently got a MF 50 running that had three new carb kits that were put in with this method. Tried plowing with it and it ran great and no problem since. Have also saw the incoming air passage on air cleaner closed down from chaff and oil where they ran poorly. Throttle shafts do wear in the body and cause air leaks.

My CARB CLEANING method includes soaking in white vinegar for several weeks then a good cleaning and rebuild. Carb cleaner is watered down junk now. I use MINERAL SPIRITS for all my cleaning jobs. Use Charcoal Lighter Fluid or Paint Thinner - it's the same stuff 100%. Never use drills, reamers, or metal probes to chase small ports. Use pipe cleaners and old guitar strings if you have to chase any holes. My old gunny sergeant "Farmer" Dan Howe taught me after the vinegar and MS cleaning as the final cleaning B4 reassembly, a plain old PINE-SOL cleaner wash works well. Air Blow is required as well. Use a wide-blade screwdriver or chisel-like tool for the Float Seat install, a 3/8" 6-PT, DEEP WELL socket and handle driver, and a 1/4" DRIVE Socket Wrench. I use the TISCO CARB KITS exclusively. Do not use any plastic parts; they're junk. Think you have a 'basket case' carb? Here's a M/S TSX 33 Carb I got from a 9N that was setting in a field for ten years; before & after. Unit ran perfect, on a different tractor, and required one minor tweak.

Tim Daley (MI)

 

[buickal]

Eman85 made a good point about the air cleaner. Have you tried running it without the air cleaner? Also make sure the choke is actually open.
Air leaking in around the manifold or throttle shafts would make it run lean not rich.
Keep us up to-date.

I did try running without the hose that goes to the air cleaner from the carb but it didn’t make any difference.

 

[showcrop]

You need to do a whole lot more troubleshooting or else go into a little detail about why "it seems"

 

[buickal]

You need to do a whole lot more troubleshooting or else go into a little detail about why "it seems"

Compression check…good. Spark throughout ignition….good. Fuel to carb….good. Need to check air cleaner but did try running without air cleaner hose hooked to carb….no change. Plugs….properly gapped and new. Points….switched to igniter and properly wired with 12v as required. Coil….new 12v coil. Wires….new. Head/valves/valve springs all redone by professional mechanic and tractor ran nicely at that time. Voltages to coil and igniter all verified as correct. When running adjustments to carb do not make a difference in how it runs until you get to a point where it does from fuel or air starvation. From what I know, turning those screws should affect how it runs before getting to starvation point.

That’s all the testing and diagnosis I have done so far. As I said though, had carb rebuilt by a diesel equipment mechanic but it still ran poorly.

 

[Eman85]

Good isn't a specification. Fuel flow measured into a pint jar and timed, spark tested with a spark tester set at 1/4" gap.

 

[old]

Compression check…good. Spark throughout ignition….good. Fuel to carb….good. Need to check air cleaner but did try running without air cleaner hose hooked to carb….no change. Plugs….properly gapped and new. Points….switched to igniter and properly wired with 12v as required. Coil….new 12v coil. Wires….new. Head/valves/valve springs all redone by professional mechanic and tractor ran nicely at that time. Voltages to coil and igniter all verified as correct. When running adjustments to carb do not make a difference in how it runs until you get to a point where it does from fuel or air starvation. From what I know, turning those screws should affect how it runs before getting to starvation point.

That’s all the testing and diagnosis I have done so far. As I said though, had carb rebuilt by a diesel equipment mechanic but it still ran poorly.

Firing order has to be correct and hook to the correct plugs

 

[buickal]

Firing order has to be correct and hook to the correct plugs

That is all correct per the factory manual

 

[old]

That is all correct per the factory manual

Ah but which cylinder to you is #1??

 

[buickal]

Good isn't a specification. Fuel flow measured into a pint jar and timed, spark tested with a spark tester set at 1/4" gap.

I have never heard of measuring fuel flow into a mason jar with a stop watch. What I know is when the shut off valve is turned on, fuel flow from the fuel line is a steady stream. These are gravity systems not pressurized systems. Didn’t see anything in the manual about that. As for spark tester, I set the plug gaps and those are correct and I know that the plugs are firing because I verified that with each of the 4 plugs plugs. Now whether that spark is the right voltage I cannot say as I don’t know how to measure the spark at the plug end.

 

[old]

I have never heard of measuring fuel flow into a mason jar with a stop watch. What I know is when the shut off valve is turned on, fuel flow from the fuel line is a steady stream. These are gravity systems not pressurized systems. Didn’t see anything in the manual about that. As for spark tester, I set the plug gaps and those are correct and I know that the plugs are firing because I verified that with each of the 4 plugs plugs. Now whether that spark is the right voltage I cannot say as I don’t know how to measure the spark at the plug end.

Are you doing the fuel flow test at the drain plug on the bottom of the carb?? The flow out of the drain plug needs to fill a pint jar in less then 2 minutes and yes catch the gas to look for dirt water etc.