IH 674 gas - Replacement Clone Carburetor?

Howitzer

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I have another related post on this topic, IH 674 gas tractor, C-200 motor. Fouls plugs constantly, tractor runs like crap.

My question - we did a carb kit a while back but the tractor still runs crappy. Marvel-Schebler carb, I believe it is a TSX980SL model. Can one purchase a clone replacement of this carb? I predict that numerous people are going to say that a possible clone would be a cheap Chinese knockoff that would emphasize the old statement "you get what you paid for"... thoughts?

Otherwise the replacement carbs are pricey, $400 - $500... more than I was hoping to spend.
 
It’s not the carbs fault on fouled plugs. Lots of things come into play. Engine wear is a big factor. Spark plugs , engine temperature , and of course the carb setting. Let’s see what the plugs look like. They can foul from burning oil to the carb being run rich. And of course you need the engine up to operating temperature with a thermostat. No short stop and starts . And the engine will suck up all the gas it can from a carb. It has to be properly tuned up.
 
I have another related post on this topic, IH 674 gas tractor, C-200 motor. Fouls plugs constantly, tractor runs like crap.

My question - we did a carb kit a while back but the tractor still runs crappy. Marvel-Schebler carb, I believe it is a TSX980SL model. Can one purchase a clone replacement of this carb? I predict that numerous people are going to say that a possible clone would be a cheap Chinese knockoff that would emphasize the old statement "you get what you paid for"... thoughts?

Otherwise the replacement carbs are pricey, $400 - $500... more than I was hoping to spend.
Just a shot in the dark. My 424 is supposed to use 30 wt. oil according to the manual so I ran it for years and constantly fouled plugs. It also used a lot of oil. I decided the try running 10w 40 multi gade oil and it still uses oil BUT no longer fouls plugs.I think the additives in modern multi grade keep it from fouling the plugs. No idea what oil you are using but this was my experience.
 
It’s not the carbs fault on fouled plugs. Lots of things come into play. Engine wear is a big factor. Spark plugs , engine temperature , and of course the carb setting. Let’s see what the plugs look like. They can foul from burning oil to the carb being run rich. And of course you need the engine up to operating temperature with a thermostat. No short stop and starts . And the engine will suck up all the gas it can from a carb. It has to be properly tuned up.
Thanks for the response. It's my brother's tractor, he says he tested the compression and it was ok. The plugs that foul are quite black but not overly oily. The head was re-done a few years ago. Maybe the carb float has a hole and is faulty, we will check.

If we need a carb, can one get a cheaper aftermarket clone for this tractor?
 
Just a shot in the dark. My 424 is supposed to use 30 wt. oil according to the manual so I ran it for years and constantly fouled plugs. It also used a lot of oil. I decided the try running 10w 40 multi gade oil and it still uses oil BUT no longer fouls plugs.I think the additives in modern multi grade keep it from fouling the plugs. No idea what oil you are using but this was my experience.
The compression was apparently ok and I don't think it burns much oil.
 
No dought as u have given no info as to how the tractor is being used. A mechanic with hands on experience can fix that problem. No idea what plugs are in it now nor any other info u have supplied.
 
Some years ago [15?] I was at where you are now, ready to buy a $$$$$ carb for my 574 gasser - It ran like crap [when you could get it started] I'd been through all the easy stuff, plugs, wires, points, gas filter etc. A good friend stopped one day when it was running, sat there listening to it and I quote "before you spend the money for the carb, get your book out & adjust the valves" So I did, The exhaust were so loose they were probably opening half of what they should, intakes just about as bad. I did it with a feeler gauge, tractor idling, each one I did you could hear the the engine run better. I don't have a comp gauge, but I'm guessing they would have read good. When they aren't opening, I suppose you'd have really good compression. Let us know here what you find -
 
Have you checked the air intake for a blockage? A dirty air filter
can lead to the problems you describe. Check also for a collapsed
hose in the air delivery to the carb.
Not so likely ---is the choke plate opening all the way?
Jim
 
Have you checked the air intake for a blockage? A dirty air filter
can lead to the problems you describe. Check also for a collapsed
hose in the air delivery to the carb.
Not so likely ---is the choke plate opening all the way?
Jim
I will check on these questions and hopefully get the answers.
 
Some years ago [15?] I was at where you are now, ready to buy a $$$$$ carb for my 574 gasser - It ran like crap [when you could get it started] I'd been through all the easy stuff, plugs, wires, points, gas filter etc. A good friend stopped one day when it was running, sat there listening to it and I quote "before you spend the money for the carb, get your book out & adjust the valves" So I did, The exhaust were so loose they were probably opening half of what they should, intakes just about as bad. I did it with a feeler gauge, tractor idling, each one I did you could hear the the engine run better. I don't have a comp gauge, but I'm guessing they would have read good. When they aren't opening, I suppose you'd have really good compression. Let us know here what you find -
We did set the valves (when we re-did the head) a few years ago. Maybe they need to be reset, maybe there's a bent push-rod or a worn cam lobe or two.
 
Well I'm warming up this post. My brother decided to purchase a new Zenith 14996 clone carb off of ScAmazon. We put it on the 674 today and it ran alot better. The problem is that when we shut it down, the carb starts to leak considerable amounts of fuel out the main air intake port. We took off the float bowl and tried to free up a possible sticky float needle and/or float. It didn't make any difference - the carb still leaks fuel like crazy when the tractor isn't running. My brother says the old carb did the same thing. Fuel in the oil is still an issue too. Anyone know what's going on? Is the carb faulty and need to be returned? Maybe the floats are faulty...

?????
 
Well an updraft carb when you shut it off or quit cranking as it drawa fuel air mixture up the pipe when you shut down or quit cranking the mixture has to go somewhere and it drops back down the pipe so you see it. Now it sounds like to me it is running a bit rich based on the fouled plugs with no oil on them. IF it runs gas through the carb in more than a dribble or mist at shutdown then a leak at the float is likely.
 
Well an updraft carb when you shut it off or quit cranking as it drawa fuel air mixture up the pipe when you shut down or quit cranking the mixture has to go somewhere and it drops back down the pipe so you see it. Now it sounds like to me it is running a bit rich based on the fouled plugs with no oil on them. IF it runs gas through the carb in more than a dribble or mist at shutdown then a leak at the float is likely.
When we installed the new clone carb, we didn't have the air cleaner/ducting tubing hooked up yet. We ran it with the air cleaner/ducting tubing disconnected (tractor ran quite good) and then we shut the tractor down. Within 15 seconds, a fog/stream of gases slowly came out the main intake throat of the carb body, then fuel started to drip out the main intake throat of the carb. We did try to free up a possible sticky float needle, but it didn't seem to help.
 
Wrong size venturi which CNH part# would get U. Don't recall right size but called carb rebuilder @ Riley Tractor for correct one.
 
Well I'm warming up this post. My brother decided to purchase a new Zenith 14996 clone carb off of ScAmazon. We put it on the 674 today and it ran alot better. The problem is that when we shut it down, the carb starts to leak considerable amounts of fuel out the main air intake port. We took off the float bowl and tried to free up a possible sticky float needle and/or float. It didn't make any difference - the carb still leaks fuel like crazy when the tractor isn't running. My brother says the old carb did the same thing. Fuel in the oil is still an issue too. Anyone know what's going on? Is the carb faulty and need to be returned? Maybe the floats are faulty...

?????

If you can return the carb I would. My experience with the cheap clones is 2 out of 3 are good. As long as you buy from a seller that allows for returns the only thing you are out is time. If you get one that doesn't work with basic adjustments - send it back and don't fight it - you can't win. The next one will hopefully work as it should. It been my experience on everything from Kohler engines on Cubs to the carb on my old F150.

I have no experience with a carb for a 674 but just in general with carbs on older engines that have limited value.
 
When we installed the new clone carb, we didn't have the air cleaner/ducting tubing hooked up yet. We ran it with the air cleaner/ducting tubing disconnected (tractor ran quite good) and then we shut the tractor down. Within 15 seconds, a fog/stream of gases slowly came out the main intake throat of the carb body, then fuel started to drip out the main intake throat of the carb. We did try to free up a possible sticky float needle, but it didn't seem to help.
Another attempt, perhaps several more attempts, may be required to resolve the issue. Make sure the float is not hanging up on the side of the bowl.

Before you reinstall the carburetor turn it upside down and blow in the fuel inlet with your mouth. With the carburetor upright you will hear air hissing into the bowl. With the carburetor upside down, you won't be able to hear air hissing into the bowl. It may be beneficial to do this with the bowl off so you can listen for the slightest hiss.
 

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