Carb Setting On IH 400 (McCormick)

[junqueyardman]

I procured an ancient tractor that ran fine for about ten minutes. Long story short, cleaned out fuel bowl , and had to remove brass filter at end of line going into carb because it was full of grit. Carb is updraft model, has two screws on side and one at bottom. Set side screws at 11/2 turns each. Loosed screw on bottom to see if fuel in carb, discovered it has a valve screwed all way in . Loosed it one turn and locked down with nut surronding it. Tractor cranks with a breath of ether, runs about ten minutes and quits. Throttle control has no control at all. Tractor has huge rear tires, two right together in front , power steering and a front end loader.(thats why I bought it). I need to get thing running as I don't need a pasture decoration ! As far as model, thats what seller told me. Neighbor said tractor was known as "widow maker" because it will rear up easily. Wifey says sell it as is. Probably at a big loss so I need to get it running. Don't recommend dealer as this area is now the suburbs and the dealers sell mainly lawn mowers. Any help is appreciated. thanks, James

 

[scott_vt]

Afternoon junqyardman,
Welcome to TBN !

I will post a pic of a Farmall 400, is this what you have ? If the tractor starts and runs 10 minutes Im willing to bet that your getting crud in your carb from the gas tank and this is stopping your fuel flow ! You need to look inside your tank to see how much rust and crud you have ! You may have to remove the tank and clean all of that out before proceeding ! I used an old paint mixer with a box of 1/4-20 locknuts to claen all the crud from mine ! It worked out great. Some people go the extra mile and coat the inside of their tank with a protective coating but mine got so clean that I didnt think it was necessary !

 

[BobG_in_VA]

It's either the gas tank crud, or the coil is bad (once it gets to a certain temp, the coil fails). Check for spark at the plugs when its not been run and will start (Also, I assume you have a coil/distributor rather than a magneto). Once it quits, check for spark again. If you don't have spark, change out the coil. If its the crud in the tank thing, you can fix it a couple of ways (one has already been mentioned. Another way is use a magnet....guess what ALL the stuff in the tank is ferous. Get a strong magnet and stick it under the tank behind the bowl (you will find a depression, that's where you put the magnet). As the stuff comes off the walls of the tank it will be pulled to the location of the magnet and not be released to go down to the carb/bowl. I've fixed a couple of Farmalls this way and yes, you should clean the tank, but this will also work if you don't want to go thru that hassel. Good luck and let us know how it goes. BobG in VA

 

[scott_vt]

Hi Bob,
Coil is a good point also, was kinda thinkin about that but leaned more towards the gas tank problems ! Hope your doin OK !

 

[BobG_in_VA]

Hi Bob,
Coil is a good point also, was kinda thinkin about that but leaned more towards the gas tank problems ! Hope your doin OK !

Scott: Doin' fine down here below the Mason-Dixon. Weather has been dry but beautiful for the last few days. Hope all is well up there....Ice gone off the rivers yet??? (grin) BobG in VA

 

[Soundguy]

If the throttle does nothing to the carb.. I'd look at the governor..

soundguy

 

[scott_vt]

If the throttle does nothing to the carb.. I'd look at the governor..

soundguy

Mornin Chris,
Gee maybe I need reading glasses recalibrated ! Just reread original post and caught that sentence, thats a good point, or something is totally disconnected !

 

[Soundguy]

It wouldn't be the first time I've seen a disconnected butterfly lever from a governor.. or.. it could just be a bad governor.. etc.... stuck butterfly.. etc..

Soundguy

 

[junqueyardman]

Thanks to all posts, I'll go from easiest to hardest. I felt the coil, it wasn't hot. Governor appears to be hooked up. Tractor has points which will be converted to electronic in the near future. Original question: settings of and functioons of three screws on carb. When facing, have two, one above the other. At bottom of bowl I thought was drain plug it in fact has what appears to be carb stem. You use the nut to unlock, set and lock again. I set all the screws at 1 and 1/2 turns to crank initially. Screw on bottom of carb appears to control speed, others will eventually make it quit if turned enough. I'll definitely clean tank and maybe seal if I have any left. I've soaked , blown out and replaced copper(?) fuel lines. Don't know if original or not. Sorry to be so wordy but I 've found telling exactly what I do sometimes saves a lot of trouble. I grew up on a farm, left it to see the world and retired to another. I'm relatively handy mechanically, I also build street rods. Again thanks for all help so far.

 

[BobG_in_VA]

Did you ever figure out what tractor you have??? I noted the 400 Farmall, but I didn't notice what your response was....Dumb question: Do you note that there are more than one fuel tanks on your tractor???That carb kinda sounds like a "distillate" carb to me......BobG in VA

 

[scott_vt]

Did you ever figure out what tractor you have??? I noted the 400 Farmall, but I didn't notice what your response was....Dumb question: Do you note that there are more than one fuel tanks on your tractor???That carb kinda sounds like a "distillate" carb to me......BobG in VA

Mornin Bob,
He PMed me and told me that the tractor pic I posted was what he had ! I believe he is still working on it Bob.

 

[junqueyardman]

The tractor I have is exactly like the one pictured, color and everything, right down to the front end loader.(the reason I bought it in the first place) I've only found one fuel tank on this beast, it does have a new radiator , hoses and belts ! The carb looks like what was on pre 30's cars and was called an updraft type. Should work better as a downdraft but I don't feel like making a new manifold for it. Gas tank currently off, been cleaned, treated and a new epoxy liner has been applied. Waiting 24 hrs to dry. Let you know of progress after Memorial Day. I have a convention of Army Buddies to attend. Sadly, its getting smaller every year but that's life .

 

[BobG_in_VA]

..... Gas tank currently off, been cleaned, treated and a new epoxy liner has been applied. Waiting 24 hrs to dry. Let you know of progress after Memorial Day. I have a convention of Army Buddies to attend. Sadly, its getting smaller every year but that's life .

Good on ya! Updraft is not a "detractor" (pun) for this type engine. Once tuned correctly will only take a half rotation of the crank to have it running, and running with authority...You ain't gonna believe how much HP you have at your disposal for an engine that only turns over at about 1650rpm....On this Memorial Day weekend, we thank you for your service and remember all those that gave the ultimate sacrifice so we can sit here and do this type of stuff. Thanks again...BobG in VA

 

[art]

On most all carbs I start out with the screws one and one half turns out and then I fine tune them.

 

[RoofDawg]

I have a 450 did same thing float was stuck. Disassembled the carb, cleaned it up, blew it out with air fired right up

 

[d.sizer@sasktel.net]

Did you ever figure out what tractor you have??? I noted the 400 Farmall, but I didn't notice what your response was....Dumb question: Do you note that there are more than one fuel tanks on your tractor???That carb kinda sounds like a "distillate" carb to me......BobG in VA

unless the carb is from an other tractor the 400 was never a distilate burner.the only way to really know if the problem is carb related is to take it off & give it a cleaning. the jet on the bottom is just a holder for the main jet that can only be removed when the carb is apart. you will no doubt find lots of crud . you will have to clean the tank for sure. hope this helps .