Perfect instruction and great advice... née sub here. Always need some good advice this is the best on RU-vid.... I followed your advice and got my Allis Chalmers B working after it was sitting for 25 years... runs like new now! 👍
Good information. Carburetors are fairly simple, and in most cases can be rebuilt using the proper carburetor kits, especially original 8N carburetors. The aftermarket carburetors for 8N tractors are not all machined to OEM tolerances.
Thank you for the great advice! I have a suggestion for a new topic: Magnitudes. I just took on an old Oliver CO3 crawler and I'm very hesitant to work on its points in fear of messing up the timing.
Previous owner installed a Chinese after market carb and my tractor dies going up hill only. Is there a way to repair that float so it doesn't close off fuel going up hill? Or do you think the needle is sticking and not releasing? The needle has spring tension, correct. Any advice you can give would be appreciated. Great presentation!
Thank you for your time and clear explanation. I was wondering what is the adjustment on the number of turns on the main big I guess you called load screw, the one in the front side of the carburator? Thank you very much.
@@AtlastaFarM Thank you very much. The original carburator just cops total attitude, the tractor won't run at all after I took it apart and cleaned everything. It looks like cast iron. Then I had acquired another one, seems to be aluminium, the tractor runs with it but it is rough to say the least. I took it apart, cleaned everything, blew all the holes with air. On one hand I have to use to choke to get the tractor started and on the other hand I see gas in the neck of the carburator where the air intake pipe gets attached to. That seems that there is plenty gas on one hand and on the other one has to choke it. I gave up on the whole thing and I ordered a new one, hopefully will be here in the next couple of days and it will actually work. I also checked the governor. Took it out and I guess You spin the gear and see if the linkage kicks back. If it does, the governor is good, that is what a gentleman in another video was mentioning. So I installed it back. I took the distributor out. Everything looks clean and good. I did notice the 4 contacts on the cap, they looked like they were all being scrapped by the rotor. My experience back in the day was when I had replaced them in car, there were some sign of that on the cap but I don't recall being to this extent. So along with the carburator I ordered complete tune up kit, wires, plugs, cap, points, all that. I checked the compression, on all 4 cyclinder they were within 90-95 lbs each. I am hoping that the new carburator will work ( I heard that all these things are made in China and that it is all questionable anymore). There was about 1 gallon of gas left in the tank that was in it clear from last years fill. I poured another 5 gallons in it. I am hoping that the old gas didn't mess up the fresh one I poured there.
I did a rebuild on my 51 8N last year. A working tractor, not a show queen. Replaced and rebuilt everything from the clutch forward. It is a 6 v, + ground and the only issues are or seem to be carb issues. The tractor starts immediately, and runs like it should-until- I get on a hill with the starboard side, right, up. Then it wants to stall out. After watching your exceptional video I assume it is in the float adjustment. This is just a guess but will try it and see. Thanks for a really great video, concise and explained so even a liberal might understand it. Doubtful, but I didn't have any issues understanding it and learned a lot. I wish you could do a video as concise and explain how to fix this country........
Sound theory and worth a test. As far as the country... I just say a few choice words and forget about it. Grab more beer and go fishing. Idiots will be idiots.. and unfortunately there are plenty of those in the world today. I believe RON WHITE said it best. "You Can't Fix Stupid"
@@AtlastaFarM Thanks for the reply.... Working 40 acre "gentleman's farm in Madison County, NC and Bay River waterfront in Pamlico County. Either place has beer and fish. Come on down, or up!
Had a similar issue with my 49 8n. Get on a bad sidehill or into a ditch and the cross arm would pivot up and hit the distributor cap shorting one cylinder out, then run well when leveled out. Thought I was low on fuel.😂
OK - 1+1/2 turns after gentle bottoming out. What about the long needle needle - the other one. .5, 1, 1.5 or 2 turns? Of course this is for an initial point but some starting point on these carbs is better than not knowing. Joe
Wow, we missed this one! If you are still in the market, we would suggest going through Steinertractor.com. They are US based and sell quality parts and will stand behind them.
How is the "under load" needle adjusted??? I bought a '49 Ford 8n last spring.....but cannot get it to start this spring. It turns over but will not fire. Nice tractor but it needs attention....needs a tune up thanks for a response. I'm trying to learn to do my own maintenance...
First turn the screw down to the closed position but do not put any real pressure on it. Just tighten it snug.. then pick a reference point on the head of the screw and turn it counterclockwise at least 1 and 1/2 turns. Once the tractor is running watch the exhaust and throttle it like you are about to race . Then turn the screw counterclockwise and throttle each turn until you see puffs of black smoke when you throttle. Once you see black smoke then tighten the screw 1/4 turn and throttle it each time until you no longer see black smoke this sets your maximum fuel
Can you tell me What is the solenoid device threaded into the float bowl. It has a Electical wire that goes to the starter solenoid. What is the function of this unit....Hal
Best to see the link here... should take you directly at the time in the video where we set those adjustments >>>> ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-qL_iyNAkBL4.htmlsi=FoDLU1xGQhHzh3Pi&t=1582
Hey, thanks for the video, I just tryed to build mine, but it didn't feed gas to engine. I didn't see those two holes at the bottom. Gone to take down again. Also what should the screw on top the end be set at? Thanks A MILLION time over!
It should have one... though there are some later replacement carbs that did away with a separate jet and instead just milled the orifice to fit the adjustment screw head instead. These machines are so old now , could easily have had the carb swapped or replaced with the other style in the last few decades at some point
can u add a video of how to get the choke shaft out been scared to try mine didnt get a new butterfly with it and doesnt seem wanna come apart its a marvel schuber
We have a video coming soon ! It is a total rebuild of Marvel Shebler designs. Sorry for the wait, but most times it takes months to make these videos. Lots of re-shoots and editing, mostly because we like to use ultra simplified language and descriptions of how parts work so everyone including the most mechanically handicapped can understand whats going on. What tractor did your carb come off of?
What ?? no comments? I have some questions. Mine is leaking fuel like bowl is over flowing after rebuild. I think it was before but don't remember. Working on it for a friend. I took it apart 3 or 4 times since and it seemslike the needle and seat is working perfectly when blowing with my mouth through fuel inlet fitting. If you don't turn fuel valve off it will pretty much drain the tank overnight. Tractor (NAA) runs perfectly fine. I'm curious if it could have a crack somewhere or is there a circuit I don't know about that could cause this? I'm a very experienced (Senior Master) Mechanic for over 20 yrs at a Ford Automotive dealership but of course very little experience with Carburetors. Thanks so much if you have any ideas.
Few things to look for... First is make absolutely sure the mating surfaces (where the gasket goes) are perfectly flat , no bows, no indentations, pitting, etc. Also be sure to look how the gasket centers on each face before assembly. We have recently had issues with gaskets not being trimmed just right, or being offset in such a way that they leak internally. You are correct in the thought of a crack in the housing and many times it is in the circuit of the seat. Usually where it can not be seen inside the body of the carb. Number one issue is warping in one or both halves of the body. No matter how well it looks to fit from the outside, inside it has a gap. This is why you should check for the flatness of the surfaces. Pretty much the same as checking the deck on a block or face of a head. One other fluke we have seen before ( rarely) but enough to mention. Make sure there is no pressure build up in the fuel tank. Only a few pounds is enough to push the needle off its seat and overflow the bowl. Usually the fuel rises enough to flow out the main jet.
I have the same problem, check to see if the floats have gas in one or both- I have run across where the float has a hole in it, fuel gets in and then raises the fuel level. I have fixed brass floats with fuel in them- it is a little tricky. ANYWAY - I think the floats on this guys ford tractor- he put air to the carb and partially collapsed the floats, So I am going to try to "raise" the float adj- so the needle shuts the fuel off sooner -
Im getting fuel in the breather pipe. It was like this before with a sticky float valve. I cleaned it up and now it run really well by the sound of it. This excess fuel still persists. Where did i go wrong?
@@AtlastaFarM I and many others have messed with the carb. We have a to20 that runs half choke All So and someone else rebuiltb that carb, they way the plugs Have lots of carbon, with what I've done,you still recommend the same its with .020 gap?
Either your float is damaged or set incorrectly..... or the needle and seat are damaged or have an obstruction.. If it has been recently rebuilt, definitely check the point on the needle, cheap kits have an issue with the point of the needle being manufactured off center and will not seal the hole in the seat
Need a little more info... What model tractor? and for timing, do you mean timing the assembly in a rebuild? or just setting base operating timing on a running engine?
That can really vary by model carb and model machine it is on, but normally the same starting point as the mixture screw setting will get you going and then fine tune from there. (1) Turn both screws all the way to seat. (DO NOT MAKE THEM TIGHT! Just till they bottom out.) (2) Next, turn the screws out 1.5 complete turns at minimum each. If it seems like it is not getting fuel or not enough fuel, then turn out the load screw another 1/2 turn at a time and try to start after each turn. The load screw is the large screw located on the end or bottom corner of Marvel Shebler carbs. Some lower mounted load screws may be "tee" valves instead of a typical screw but work exactly the same.
Sorry, but no.. We stopped selling parts years ago... best place for ford is Steiner or Dennis Carpenter (google both. Carpenter is more restoration stuff.. Steiner is more into straight quality replacement parts
Wow.. just found this comment 2 years later. Soo sorry I missed it. Even though its 2 years later,... no not really. I have looked into it but have not tried yet. We are looking into an industrial ultrasonic machine for doing major components (heads / blocks etc)
Hollis Smith Have you made sure fuel flows from the tank through the line? Three carburetors means either the fuel outlet at the tank or the line from the sediment bowl to the carburetor is restricted. If no restriction then all the carburetors would have incorrect float settings or needle and seat issues. But hard to believe all three . Not knowing the condition of those carburetors...and giving the benefit of doubt that at least one of them would be good..I would have to go with the common denominator of a restricted fuel line or sediment bowl. First things first though... Pull the plug from the bottom of the carburetor bowl (usually 7/16 and use 6 point socket or wrench!) and you should have fuel flow. If not then work back from there. Take the line loose from the carb and check for flow. If good at the line but minimal to none at the drain...then the float needle setting is incorrect. If flow is good out of the drain and you are positive the float/needle settings are correct, then you need to check this video here ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-sB22u_DWMag.html
Can someone explain why my 9N was running fairly fine for an old tractor. then two days later I went to move a piece of equipment and got out in the field and all of a sudden it kept stalling out and would only run rough when I had the choke all the way out? I've check for clogged fuel line, but I got good flow to the Carburetor, but the bowl isn't filling up even though i've cleaned the jets and what have you. She turns over like she always has but it won't start.
Jeffrey Palmer try running without the fuel cap. Also try loosening the sediment bowl even to the point of dripping. Either there is a restriction in flow when the system is closed or the main mixture jet is clogged. This is all based on if you are sure it's a fuel volume issue.
Jeffrey Palmer next steps are checking for air leaks in intake. Most notably the flange where the carb mounts. Finally make sure the governor rod is moving freely. If all this tests out a bad coil will have these symptoms and make you chase fuel gremlins
Well i ended up putting the new Carb on and she fired right up just had to tune it. Just another quick question, the tractor seems to be stuck in a higher throttle and no matter where i position the throttle lever it stays the same.
you have to adjust it to lower the idle, somtimes the butterfly valve is stuck open by the screw that holds it open, you have to unscrew the screw and it will close your butterfly then the rpms should come down, the tractor should be spinning at 400 rpm at idle
We decided a live repair would be best for this model as it is such a notoriously tedious little 😈. Be sure to subscribe and ring that bell so you will be notified when it comes
