[Donttouchthat]

Just when you think all problems are solved... Just replaced the starter and turns over/cranks fine. Background, I had taken apart (I don't know much about engines but...) the Zenith carburetor about 6 mos ago cause it was running poorly. Checked the float valve and all seemed OK. Set the needle valve at recommended position. Overall there was an improvement. No problems but then after not using for many months started up one day then the next just getting solenoid click sound. Long story short finally put the starter armature on a growler and was deemed failing.

Got a starter replacement installed and started the tractor yesterday, pulled choke out like normal but engine just puttered and did not fully get going while I was tring different positions with the choke there was varying degrees of stronger turnover. Then I tried again with no choke and it started fully up. Dug my trench for a good 2-3 hours then shut it down for the day and refilled the hydraulic fluid (it leaks) and topped off the gas. Tractor is on a slight downhill slope. Today I can't get it started just sputtering. I pulled apart all the fuel lines, blew some/most out with compressed air. Fuel seems to be flowing. I'm thinking that my problem is a fuel related one.

Note: all pics were from before when carb was removed. Carb not removed now. There is a large screw (see white arrow pic) at the bottom of the carburetor, I don't know what it's for but I loosened it and gas began pouring out. Is it supposed to do that? or is there something wrong with my float? How can I tell if float and needle are working without taking carb off? Any tests I can do? Is it flooded? Thanks much!

 

[fuddy1952]

I take a new (clean) piece of hose over fuel inlet. Blow through it...should of course be no resistance. As you're blowing rotate carb upside down (do this over a box if it's apart to catch parts that may fall out). As floats drop you'll feel it shut off airflow.
I have done it with air compressor set at 4-5 psi using rubber tip blow gun.
If it's flooded pull a spark plug. Wet, it's flooded.

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[FredM]

Just when you think all problems are solved... Just replaced the starter and turns over/cranks fine. Background, I had taken apart (I don't know much about engines but...) the Zenith carburetor about 6 mos ago cause it was running poorly. Checked the float valve and all seemed OK. Set the needle valve at recommended position. Overall there was an improvement. No problems but then after not using for many months started up one day then the next just getting solenoid click sound. Long story short finally put the starter armature on a growler and was deemed failing.

Got a starter replacement installed and started the tractor yesterday, pulled choke out like normal but engine just puttered and did not fully get going while I was tring different positions with the choke there was varying degrees of stronger turnover. Then I tried again with no choke and it started fully up. Dug my trench for a good 2-3 hours then shut it down for the day and refilled the hydraulic fluid (it leaks) and topped off the gas. Tractor is on a slight downhill slope. Today I can't get it started just sputtering. I pulled apart all the fuel lines, blew some/most out with compressed air. Fuel seems to be flowing. I'm thinking that my problem is a fuel related one.

Note: all pics were from before when carb was removed. Carb not removed now. There is a large screw (see white arrow pic) at the bottom of the carburetor, I don't know what it's for but I loosened it and gas began pouring out. Is it supposed to do that? or is there something wrong with my float? How can I tell if float and needle are working without taking carb off? Any tests I can do? Is it flooded? Thanks much!
View attachment 80205 View attachment 80206 View attachment 80210
View attachment 80209

The bowl nut you have arrowed is a float bowl drain plug and yes fuel will run out when all connected up, you would use this to drain bad fuel if engine was running rough.

 

[Donttouchthat]

I take a new (clean) piece of hose over fuel inlet. Blow through it...should of course be no resistance. As you're blowing rotate carb upside down (do this over a box if it's apart to catch parts that may fall out). As floats drop you'll feel it shut off airflow.
I have done it with air compressor set at 4-5 psi using rubber tip blow gun.
If it's flooded pull a spark plug. Wet, it's flooded.

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Thanks, the carburetor is still attached. Those pictures were when I did remove (about 6 mo ago) it to clean and inspect.

Yesterday 2X I disconnected the fuel line and sprayed wd40 into the inlet and then also blew into it (much higher psi though). Did not get any result. Took off the inlet and inspected the float needle, looked OK, sprayed wd40 and reinstalled. Reconnected gas line and tried to start. No go. Read about wet plugs if flooding. I took out the plugs (which I replaced 6 mo ago) and they did look a bit slimy. I hand held (grabbed the rubber boot) one connected to the spark plug wire and cranked the engine and got a shock through me. I guess I was touching something else cause I did not think I would be shocked. Was looking to see if I saw the plug firing/sparking.

So I guess I am getting a spark, which is good news. Today I will buy a new set of plugs and see what happens. Perhaps that is the main problem of not starting (insufficient spark) Then go from there. When it used to run I always had the issue of the tractor trying to die out at higher rev/acceleration

 

[Donttouchthat]

The bowl nut you have arrowed is a float bowl drain plug and yes fuel will run out when all connected up, you would use this to drain bad fuel if engine was running rough.

Got it. Thanks

 

[fuddy1952]

If carb is attached blowing into inlet won't work. When floats rise fuel cuts off, carb has to be off. You can also check floats in a cup of water to be sure they're ok.
Carb probably just needs taken apart carefully (make notes & pictures), soak clean (Berrymans, etc), blow out passages air compressor, new carb kit.

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[Donttouchthat]

If carb is attached blowing into inlet won't work. When floats rise fuel cuts off, carb has to be off. You can also check floats in a cup of water to be sure they're ok.
Carb probably just needs taken apart carefully (make notes & pictures), soak clean (Berrymans, etc), blow out passages air compressor, new carb kit.

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Put new spark plugs in this am. Didn't really do anything. At most I'll get a very slow firing then dies out within a minute. I was hoping the new plus would make the difference. I can't find any blockages. Gas still comes out of the carb bowl nut when removed, so I guess fuel is getting to carburetor. Removed a few plugs after to inspect. One had some residue, didn't have as strong an odor as gas. The other was totally clean.

Yesterday I did remove the fuel pump (not sure if that's correct, see pic )) blew out and reinstalled. When are you supposed to use the hand primer lever and why? Also what is it's function as it had a banana shaped part that reaches into the engine. Could this part have anything to do with the problem? Test?

So you think I need to take the carb apart again, but get a rebuild kit for it? Man, 2 days ago I was digging my trench for 2-3 hours then the next day no start. Thanks

 

[fuddy1952]

An old car I have fuel pump has hand primer. It's just so if car sits a long time by pumping it fills carb bowl. I almost never have used it.
Fuel pumps you can do a pressure & volume test. Your tractor I'm not sure exact specs but should be close enough:
Disconnect fuel line at carb. Put a pressure gauge on it...most vacuum gauges also check low pressure. Crank on it, pressure should be about 3-5 psi (roughly).
Then gauge off, hold clean jar with fuel line going in & crank. Should be maybe 8 oz. in 10 seconds (roughly).
Me...I'd focus on rebuilding carburetor. Of course they'll work fine then not...could be trash in fuel tank. Some passages are small.


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[Donttouchthat]

An old car I have fuel pump has hand primer. It's just so if car sits a long time by pumping it fills carb bowl. I almost never have used it.
Fuel pumps you can do a pressure & volume test. Your tractor I'm not sure exact specs but should be close enough:
Disconnect fuel line at carb. Put a pressure gauge on it...most vacuum gauges also check low pressure. Crank on it, pressure should be about 3-5 psi (roughly).
Then gauge off, hold clean jar with fuel line going in & crank. Should be maybe 8 oz. in 10 seconds (roughly).
Me...I'd focus on rebuilding carburetor. Of course they'll work fine then not...could be trash in fuel tank. Some passages are small.


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When I do hand prime it, I do hear and see gas moving in my in-line fuel filter which feeds it. So being that, I guess a vacuum pressure is being created, I can assume the seals are good and functioning properly? Go on to something else i.e. carb? Thanks!

 

[Donttouchthat]

An old car I have fuel pump has hand primer. It's just so if car sits a long time by pumping it fills carb bowl. I almost never have used it.
Fuel pumps you can do a pressure & volume test. Your tractor I'm not sure exact specs but should be close enough:
Disconnect fuel line at carb. Put a pressure gauge on it...most vacuum gauges also check low pressure. Crank on it, pressure should be about 3-5 psi (roughly).
Then gauge off, hold clean jar with fuel line going in & crank. Should be maybe 8 oz. in 10 seconds (roughly).
Me...I'd focus on rebuilding carburetor. Of course they'll work fine then not...could be trash in fuel tank. Some passages are small.


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Since I can't get a rebuild kit until Tue. I just took the carb off and cleaned everything out. Nothing seems clogged. The only thing is that maybe the float needle (with rubber point tip) may have been getting stuck closed under blowing with my mouth through inlet. I pinched of the end of the rubber still leaving a circumference of rubber in place and it seem to seal fine yet easier to back off and open. Re-installed the carb with no improvement. When I unscrewed the bowl nut, gas came out so some gas is definitely getting to the carb. I am having my doubts it's the carb but IDK. If there was garbage in the tank, wouldn't that prevent gas flow?

I can go about draining the tank but I always use a funnel that has a filter screen. I pulled off the air filter pipe at top of carb to expose the carb. Tried starting it and no improvement.

 

[FredM]

I think it is about time you checked the actual spark for colour, pull the plug lead from any plug and connect to a plug that you removed and replaced, place the plug on a good earth point and have someone crank the engine while you check the spark at the plug electrodes, a blue spark is best, check the ignition points for correct gap and condition of contacts and the condenser, a crook condenser will do what you are experiencing, if you have badly arced contacts, then replace both contacts and condenser, with a good American or British made one.

An old saying, "if you think you have fuel problems, then it may be electrical", because both will give a similar problem and it is easier to check electrical before fuel.

If you can prime the fuel pump with the primer and you get good supply, then the diaphragm and the reed valves are ok, the long banana lever goes against the cam shaft and this gives the pumping action, you have to be sure when inserting the pump that the lever actually goes against the cam lobe, it is easy to place the lever on the wrong side of the cam lobe, that I know.

 

[Donttouchthat]

I think it is about time you checked the actual spark for colour, pull the plug lead from any plug and connect to a plug that you removed and replaced, place the plug on a good earth point and have someone crank the engine while you check the spark at the plug electrodes, a blue spark is best, check the ignition points for correct gap and condition of contacts and the condenser, a crook condenser will do what you are experiencing, if you have badly arced contacts, then replace both contacts and condenser, with a good American or British made one.

An old saying, "if you think you have fuel problems, then it may be electrical", because both will give a similar problem and it is easier to check electrical before fuel.

If you can prime the fuel pump with the primer and you get good supply, then the diaphragm and the reed valves are ok, the long banana lever goes against the cam shaft and this gives the pumping action, you have to be sure when inserting the pump that the lever actually goes against the cam lobe, it is easy to place the lever on the wrong side of the cam lobe, that I know.

I'm going to test the plugs tomorrow like you said. I reset all the new plug gaps to recommended .025 before I installed them. I believe the previous owner ( 6/2020) had recently replaced distributor, rotor and wires. I'll need to google about ignition point gaps, and condenser. My manual says "Distributor Gap : .014" But I'll need to go through it. Good point about fuel pump alignment with cam lobe. I had no idea and just shoved it in. I'll have to remove and try and make sure proper. When you describe "prime the fuel pump" and "you get good supply" can you expound on that?
My mechanical pump with hand primer has two hoses/tube going to it. One comes from my gas tank that passes through an in line filter, then goes to the pump. The other leave the pump and goes over to feed the carburetor. How specifically would I test as you described? Would I disconnect one of the lines somewhere, then hand prime and notice if adequate (?) flow/supply is generated?
Thanks!

 

[FredM]

I'm going to test the plugs tomorrow like you said. I reset all the new plug gaps to recommended .025 before I installed them. I believe the previous owner ( 6/2020) had recently replaced distributor, rotor and wires. I'll need to google about ignition point gaps, and condenser. My manual says "Distributor Gap : .014" But I'll need to go through it. Good point about fuel pump alignment with cam lobe. I had no idea and just shoved it in. I'll have to remove and try and make sure proper. When you describe "prime the fuel pump" and "you get good supply" can you expound on that?
My mechanical pump with hand primer has two hoses/tube going to it. One comes from my gas tank that passes through an in line filter, then goes to the pump. The other leave the pump and goes over to feed the carburetor. How specifically would I test as you described? Would I disconnect one of the lines somewhere, then hand prime and notice if adequate (?) flow/supply is generated?
Thanks!

Most pump levers had to be inserted through the opening and kept close to the inside of the engine housing, sometimes when the pump lever rested against the cam lobe, you have to push against the pump lever to insert the retaining studs.

To check the pump operation, remove the supply hose from the carby inlet and place into a container and pump the lever and watch the flow, if the flow is a good squirt, then the pump is ok, if only a dribble then possibly a reed valve is stuck, but don't go there yet, you can also hold a finger over the hose end and pump the lever to check pressure as you pump the lever, be careful, can be a bit messy with fuel spray, the fact that the diaphragm is not leaking fuel shows that the diaphragm is ok and the reed valves are also ok when the fuel pump is pumping, maybe I should have said "PRIME the CARBY", I was probably thinking Prime the fuel/injection pump on a diesel engine, sorry, and fuel pump supply is the amount of fuel being supplied to the carby from the pump.

If you are not sure of what I have written, then ask questions again, I'll be happy to answer.

 

[fuddy1952]

If you don't have one, Harbor Freight $12.79 I'd get one. That way you know pump pressure.
Fred is correct, a weak spark means hard starting & poor performance.
IF you want to try this (use your judgment...I've done this test for years): an engine with good spark & compression (I assume if it ran well that's ok) doesn't even need a carburetor to run. All you need is starting fluid or carburetor cleaner. Spray some in intake, crank...it should start. Keep it running with spray. That's a quick easy test to be sure carb/fuel related.
Spark with plugs out engine will crank faster since no compression. Plugs on side on a good ground should see a good strong blue spark.
PM me, we can talk on phone better.

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[Donttouchthat]

Most pump levers had to be inserted through the opening and kept close to the inside of the engine housing, sometimes when the pump lever rested against the cam lobe, you have to push against the pump lever to insert the retaining studs.

To check the pump operation, remove the supply hose from the carby inlet and place into a container and pump the lever and watch the flow, if the flow is a good squirt, then the pump is ok, if only a dribble then possibly a reed valve is stuck, but don't go there yet, you can also hold a finger over the hose end and pump the lever to check pressure as you pump the lever, be careful, can be a bit messy with fuel spray, the fact that the diaphragm is not leaking fuel shows that the diaphragm is ok and the reed valves are also ok when the fuel pump is pumping, maybe I should have said "PRIME the CARBY", I was probably thinking Prime the fuel/injection pump on a diesel engine, sorry, and fuel pump supply is the amount of fuel being supplied to the carby from the pump.

If you are not sure of what I have written, then ask questions again, I'll be happy to answer.

I think I got it. When you start a tractor and the starter turns the flywheel, I guess the crankshaft is turning as well and then the mechanical pumps contact with one of the lobe's is sending fuel to the carb? I'll do that flow test too. It certainly is helpful to understand how these things work in conjunction. And not blindly hitting this and pumping that hoping for a positive result. Thanks!

 

[Donttouchthat]

If you don't have one, Harbor Freight $12.79 I'd get one. That way you know pump pressure.
Fred is correct, a weak spark means hard starting & poor performance.
IF you want to try this (use your judgment...I've done this test for years): an engine with good spark & compression (I assume if it ran well that's ok) doesn't even need a carburetor to run. All you need is starting fluid or carburetor cleaner. Spray some in intake, crank...it should start. Keep it running with spray. That's a quick easy test to be sure carb/fuel related.
Spark with plugs out engine will crank faster since no compression. Plugs on side on a good ground should see a good strong blue spark.
PM me, we can talk on phone better. View attachment 80231

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Thanks for the link. I do have some carb cleaner spray (can is getting a bit low) So if I take the air filter boot off the top of the carb, I would just spray into the top there while it's cranking? And I guess my choke would be off? I watched some YT video today saying starter fluid could damage a gasoline engine? Others said it was fine. I guess your with the later. Thanks! Praying for some good results tomorrow. This down time sucks.

 

[FredM]

Yes!! lots of things turning when you crank an engine with the starter motor at flywheel attached to the crankshaft, which moves the the pistons to TDC and BTC in their sequence, the crankshaft drives the cam shaft through the timing gears at half time, the camshaft drives the distributor and the valve lifters in time with the pistons and also a mechanical fuel pump if fitted, so yes a lot of things happening in sequence, and the order has to be correct.

 

[Donttouchthat]

Yes!! lots of things turning when you crank an engine with the starter motor at flywheel attached to the crankshaft, which moves the the pistons to TDC and BTC in their sequence, the crankshaft drives the cam shaft through the timing gears at half time, the camshaft drives the distributor and the valve lifters in time with the pistons and also a mechanical fuel pump if fitted, so yes a lot of things happening in sequence, and the order has to be correct.

Easy cowboy, my brain is flooded. Pretty cool. Gonna take about a week to absorb 😵😅

 

[fuddy1952]

Thanks for the link. I do have some carb cleaner spray (can is getting a bit low) So if I take the air filter boot off the top of the carb, I would just spray into the top there while it's cranking? And I guess my choke would be off? I watched some YT video today saying starter fluid could damage a gasoline engine? Others said it was fine. I guess your with the later. Thanks! Praying for some good results tomorrow. This down time sucks.

You can do test with carb removed...just spray into intake hole where carb was.
If choke is wide open, you can spray a little there, see if it runs. If it starts to die...spray a little more. If it revs up every time you spray you know for sure you have a carburetor problem.
Here's a pretty good YouTube video of engine theory:

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[Ammburbank]

I take a new (clean) piece of hose over fuel inlet. Blow through it...should of course be no resistance. As you're blowing rotate carb upside down (do this over a box if it's apart to catch parts that may fall out). As floats drop you'll feel it shut off airflow.
I have done it with air compressor set at 4-5 psi using rubber tip blow gun.
If it's flooded pull a spark plug. Wet, it's flooded.

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Ok I’ve had that ole 3414 for a while! I’ve worked on just about every issue you can think of with this thing!

First off let me tell you that a Jeep carb can be bought new for around $80 to replace that zenith. There’s not any replacements to be had really. There was a guy selling his own modeled carb and is on mine. Turned out the quality is crap! You can rebuild them but again it’s about the same as a new Jeep carb.

Do yourself a favor and bypass that mechanical pump and just install an electric pump. 3-4 lb universal. Saves future headaches.

If yours is converted to 12 volt. Check your resistor to the coil. If good check you’ve got fire going to the plugs. It could be a condenser or the points need filed. If there is good fire to the plugs. No need to look further right there. Whoever said replace plugs just cost you $. Hell this thing will chug over and run on one good plug. Ask me how I know🤣.

Now if were are back to the carb issue. Take the fuel line off where it feeds the bowl. Hang it over the side or stick it in a clean glass bottle. Crank the tractor over. See if it’s pumping. If so then it’s the carb.

Now take the top of the carb off. Connect the fuel line. Have someone crank the tractor o we while you press down on the U Spring that holds down the float. See how far the bowl fills up before the needle shuts off the fuel flow. This is time to set the fuel float and fuel level in the carb by bending the tang on the float. This is a repetitive process of removing fuel, cranking the tractor over and checking fuel level.

Make sure before you do any of this that the brass fittings that screw in behind the needle are tight and seated.

Now with the fuel level set there should be no overflow and flooding issues. It’s time to set the carb. Truly I forget the exact process but it’s on the web.

There is a fuel air mixture on the bottom. Likely won’t need to adjust this right away. There’s also a T handle adjuster. Yours might not be a t but it’s facing the tanks and on top. Screw in then back out 2 1/4 turns. It should fire right up. From there this screw can be adjusted to meter the fuel.


This is brief and a quick, crude and poor attempt to help you get her going again. I know how it feels to be at a loss. Good luck buddy I hope Ive helped a little!