I have a 51 farmall h that just up and quit running about 5 years ago. I have changed the condenser, put a new fuel system on it, plugs, wires, cap, rotor, all new ignition system, carb kit, and have cleaned the carb numerous times. I have fire at all the plugs. When you crank it over it will not start. To get it to even fire you have to pull the air hose off, choke it for a few cranks, let the excess fuel run out of the carb, crank it again unchoked then it will fire but you have to hold it at 3/4 choke to keep it running but it smokes and runs something terrible. something else that is odd is that when it is running there is smoke coming out the governer tube, but only when the tractor is running. I have good vacuum going into the carb when cranking. Any ideas would help please.
- Thread starter turner84
- Start date
Janicholson
Well-known Member
I am going to recommend that the intake manifold could be broken (rust through) internally. Remove the muffler, and using a strong light, look down the pipe and see if there is a hole between the exhaust and intake plenums. different (kinda radical) test would be to pull the valve cover, lemove a the rocker shaft and rockers and pushrods (keep them in order) drain the carb, and shut off the fuel. Put a shop vac (blow not suck) hose on the carb intake with duct tape and push air into the intake system. If air blows out the exhaust pipe, or any where else, there it is. It should hold pressure well. ...... DO not use the suction side of the vacuum..... If air blows out of the exhaust pipe, suspect that crack mentioned above, or a broken/stuck valves. If it comes out the vent tube, suspect a hole in a piston, or cylinder wall. If it comes out the radiator cap (removed) head gasket (Not likely) If it comes out around the manifold to head mating surface, there it is. If all seems tight, and the pressure stays inside, you know that the intake valves are OK, and the manifold is tight. Jim
Make sure your venture is still in the carb. Would not be the result of it stopping 5 years ago but that may have been resolved with one of the repairs you have done. I have had them fall out of the upper casting between pulling off the lower cleaning lower bowl and replacing in a hurry and finding it on the ground after.
used red MN
Well-known Member
- Location
- Coon Rapids, MN
Jim, that is an interesting suggestion for diagnosing his problem. I do see one possible ...slip of the brain cells... when you say ...If it comes out the vent tube, suspect a hole in a piston, or cylinder wall... When the rocker arms are removed the combustion chamber and pistons are taken out of the test zone. Of course this counts on the fact that the valves are closing and sealing properly. All this is assuming you meant the crankcase vent tube below the oil filter.
used red MN
Well-known Member
- Location
- Coon Rapids, MN
It sounds like a couple suggestions here are quite likely your issue. As you can probably surmise if you need 3/4 choke to make it run there is a high likelihood that the carb is not providing the proper air to fuel ratio. I would suggest a compression test, not very likely that this would show up an issue that caused your tractor to stop 5 years ago but rather a valve that has stuck during the sitting period. On the smoke at the governor tube I would suggest checking the crankcase vent tube for plugging. If you have dirt dauber wasps around your area this is a great little location they like plug up. This would have no affect on how you tractor runs but it will build pressure in the crankcase and make it push it out at the governor tube as well as make it likely to leak more oil at gaskets and seals.
Janicholson
Well-known Member
Venturi is the correct spelling, it is a smoothly necked down area in the construction of the carb that creates a suction through bernulies principle, and gas flow (not fuel) of air to suck fuel up and out of the bowl. Google it. Jim
used red MN
Well-known Member
- Location
- Coon Rapids, MN
Venturi..Number 10 in the diagram in the link. I was afraid of this, first time posting a link to the new CaseIH parts website and of course it will not take you direct to the diagram as it would with the old site. You will have to click 036 carb section then on the bottom click the picture diagram to show the exploded diagram. At least these are the steps on my iPhone.
H carb diagram
H carb diagram
Similar threads
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.
Copyright © 1997-2024 Yesterday's Tractor Co.
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy