Need help with AC B manifold issue again

Thanks to the help here of other the manifold has been replaced. I got the new studs with brass nut like recommended. They all came out except two but the vice grip idea goth them out as well. Thanks for the help.

So all back together with everything in place where it was. I crank start the tractor till I can do no more. Get a tow with the truck and finally after much towing the tractor started and ran very poorly only to stall. Nothing I did after that had any effect. The tractor just won't start.

Things I know are that there is fuel through the carb. There is spark, weak or not, there is spark. Air I haven't verified yet. I ran out of time and had to stop for the day. I plan to take that short hose off the air cleaner to the carb and see if that has any effect. Could it have run by having the hole in the manifold to draw air and now because there is no hole it can't get the air it needs so it won't start? I an at a loss as to what the issue is. Any help? Any thoughts?

Time to trouble shoot.
#1 check that you have a good blue/white spark at all the plugs that jump a 1/4 inch gap or more. Since you say you cranked it till you could not do so any more it has a mag right?? If yes are you sure the impulse is working because if it isn't then you can crank it till your blue in the face and die of a heart attack before it will start.
#2 pull the carb drain plug and make sure you have a good steady flow of gas that will fill a pint jar in less then 3 minutes.
As for the air cleaner when was the last time you serviced it and dumped the mud and water out and put in fresh oil

I've been running this tractor right regular right up to this Monday Old. It ran before the manifold with a few turns with the crank. This was just Monday. I would believe the impulse to be in working order. I've not had this issue with the tractor plowing fitting and seeding this spring.

It's got a mag. I'm sure there's spark but just to be certain I'll test it when I get to it tomorrow. The gas hasn't been an issue other than over a month ago where it acted up one night spreading manure. Since then good running tractor. As to the air cleaner there is a problem that I caused myself last fall. I took the cultivators off the tractor and put a small hole in the cup. It leaks out the oil and it's been dry for a few running's of the tractor. Need new cup and refill with oil. So presently the cup is dry and clean. The wire mesh inside is another story. I've never taken that out and haven't cleaned it that I recall. Not sure if that is something I know how to do really with getting it thoroughly clean.

So tomorrow I'll test the spark, test the fuel flow, and see if I have issue with those two and if so fix and check them off the list. Small steps I guess. I'm just dumb founded to understand a running tractor earlier isn't now with just a manifold change. Thanks Old I'll be back with some more answers.

No oil in the air cleaner is not good. As for cleaning the air cleaner a 5 gal buck of gas and an over night soaking goes a long way in cleaning it. As for the oil cup I may have one laying around since I have 2 C parts tractor on hand. One thing to check if you have help is take the air cleaner off and then while you have some one cranking the engine hold you hand over the air intake and see if you get a good suction and gas on your hand. Lack of suction means you have something wrong with the new manifold be it gasket or a China want-a-be manifold. Now days sadly many new parts are not worth buying due to being make poorly

When cranking, shoot some ether around the manifold ports. You may have a large leak around the gaskets. If it hits on ether, you know you have a bad gasket seal.
AaronSEIA

Dumb questions I have this morning, I put the gasket on without any sealant. I didn't see where the old one had any either. If sealed generally the gasket generally doesn't come off. If it needs to be sealed I guess I have missed that part. Also thinking if the gasket were slightly miss aligned would that cause enough trouble to make the tractor not start? I think I have it pretty well aligned but am thinking this issue through for any possible cause.

One thing drummed into me when taking flying instructions was, anytime you have a problem with the engine while in the air quickly undue what ever the last thing you did. I find this works on about most things.

I wouldn't be changing tires or steering wheels until made sure the things you worked on was rechecked by removing the items and inspecting them. I would guess the carburetor has been turned over or bumped some. That might be a good place to look if the manifold gasket is sealing. You might want to re try the old manifold. Because you have gas coming out of the bottom of the bowl does not mean it can get from the bowl into the firing chamber.

Sealer on a manifold gasket is not needed! Lay a straight edge on the manifold ports to make sure you do not have gaps under it. Look for deep pits on the head around the ports. First put you hand over the throat of the carburetor and feel how much suction you have. That will mean disconnecting the air cleaner. With the hose off the carburetor will tell you if you have an air cleaner problem. The don't need an air cleaner to run they need it to keep dirt from being sucked into the engine. With the air cleaner off you don't get dirt into the jets of the carburetor only into the firing chamber.

Okay I had time to give the tractor a bit of trouble shooting. I verified spark was good. It would jump 1/4 with out issue. Same result would not start. I took off the air cleaner and tried to start the tractor. Same result would not start. I verified gas out of carb from bottom plug. Filled pint jar in 2:20. Fuel is good to carb. I then looked at old manifold to see what I may have missed. I found that the gasket between carb and manifold was not reinstalled. I put it back on the tractor. Same result wold not start. I checked for suck at the carb air intake. It would suck my hand in as I cranked the tractor. So I guess it was doing what it is supposed to do. I guess, I will tomorrow, take the new manifold off and put old back on to verify tractor runs.

Dick when I took the carb off to replace the manifold I didn't move the carb to far. It was attached to the air cleaner and I just moved aside to get the manifold off. It was always near where it generally is. I did take care not to get anything into the carb or in the ports of the head. The old exhaust gasket has broken into two or more pieces and isn't any good. I can't reuse it.

I'll change the manifold back to the old one and check over the new one for issues I didn't see. This is baffling me what it could be. I'll post my results.

If the only thing you did was to switch manifolds and you have good suction on your hand with plenty of fuel flowing out the bottom of the carburetor it has to be in the carburetor jets. Remove the carburetor then take the plug out of the front of the carburetor. See if you can see dirt in front of the main power jet.


They don't run when you have dirt behind the plug like in the picture.

The tractor is now running. Last Saturday my uncle came over to lend a hand to diagnose the issues with it not running. We went through the things I had checked again and still the tractor wouldn't start. He had brought a carb over from another B that runs. We swapped out carbs and in a few cranks the tractor was operational. Seems the carb got something in it that caused the issue all along. He left his carb on the tractor so I could use it and till I could rebuild my carb. Got the carb cleaned up and rebuilt and back on and the tractor runs like it used to do. Surprised it was something in the carb. I took care not to get anything down in that when I changed the manifold but I guess I didn't keep it all out. Oh well lesson learned. Next time I'll take the carb all the way off and set it out of the way. Was trying to save a minute or two but it cost me days. Thanks everyone for your help.

Sometimes all it takes is moving a carb around to shake up a little rust/dirt in them and then you have a clogged jet some place

I find after all this manifold and carb work that the tractor is down on HP. Is changing a manifold have anything to do with it? Seems the tractor runs smooth but every once and a while it just stalls out for no reason. There isn't an adjustment on the carb I didn't do is there? I see only one screw to adjust on the carb.

Adjusting your carburetor without a power/main jet adjustment is only an idle air adjustment. This for slow idle. The slow speed(RPM) is determined by the stop screw on the throttle plate lever on the back of the carburetor. If the stop screw is set for the throttle plate to close no fuel can get into the engine. As the stop screw is changed to open the throttle plate the engine will run faster as the throttle plate opened farther. If the air mixture screw(idle screw) is not adjusted as the throttle plate is opened the engine will die because it is not the correct fuel air mixture. That means they have to be adjusted together to keep the engine running smooth. Personally I like to have my idle set as slow as it will run and still go to high idle without faltering.
That is the only adjustment you have on that carburetor. To change the main jet is to replace it with a different orifice. (small hole in the center) That would only help if you have changed the piston size and speed of the engine to where the orifice will not support the extra fuel needed from the changes.