Marvel ShemblerTXS 827 carb main fuel adjustment

marlin54

Member
So I have a International 404 utility and it has a C 135 gas motor. I have had the carb apart 10 time sand cant figure out why it is starving for fuel...I found just 1 port pluged and cleaned it out. .and why is there seem to be just 1 needle screw on the top to adjust on the TXS 827 carb? Well does anyone know which way you tur the needle for rich and lean? What is the procedure if it is too lean and wont run ...
 
Ok So I now found out that there is 3 typs of carbs for itn...2 with main fuel djustment screws and then the one i have which i called the FIXED JET CARB ..well no wonder i cant adajust it ,,.....but its being starved ?..wont even run...what now? what kind of idiot made this style of carb ...How does It work
 
Well more then likely you should have the one with the electric solenoid . With those once you turn the key on you should hear a CLICK with the solenoid , the Pintal Should move off the main fuel jet and allow for FULL FUEL delivery . This was so that when you turn the KEY OFF fuel is stopped and no run on when the engine was HOT. Now not seeing and being around your tractor i really don't know what we are working with . BUT just because you have had that carb apart how many times this tells me you don't really know carbs all that well . And cleaning a carb with a spray can of carb and choke cleaner IS NOT CLEANING A CARB . To do the job that chunk of Iron or aluim. needs to talke a deep soak in some real carb cleaner for no less the 24 hours then each passage and drill hole needs to be manually cleaned with Tiny number drill bit and sometimes vary fine torch cleaner drill bit and NOT try and force one to large down a hole when you don't know what your doing . Next up is making darn sure you have proper fuel flow from the tank and also your float level is correct and you have good flow thru the needle and seat . Then ya need to take a look at the gas your tryen to run . The gas your car or pick up runs on to day is NOT what these old tractors were designed to run on , No i don't give two hoots in hatties about the LEAD it's the octane . And back then FARM gas was 93 reg for cars at the corner gas station was 95 .
 
well I have had over 200 tractors over 35 years and only maybe 4 or 5 ran when I got them. alsoI spary carb cleaner thru each and every possiblre port and cleas with welding tip clenersand I spray thru each prt to make sure its open. and no the electric choke came in about 1969 and its before that. I have plenty of good supply..I have it runs grest for 4 secons then dies and I have the float set about 1/4 inch so it is NOT runnin out of gas,,,problem i s there are 3 models of marvel TSX 827 carbs...there are 2 with adjustablr main needles jets and the odd one is the FIXED JET one ..I read abut it all last nite and it really does not explain it how it works but it seems it all has to do with the choke.... dum idea not having a main fuel jet . so if your that smart then maybe you can explain the FIXED JET SETUP and how it works?
 
When you adjust a carb with an adjustable main jet you tune in the proper air-fuel mixture for it to run properly. Once it is set if all goes well you can run the engine for years at that setting and have no need to touch the main jet adjustment screw. A fixed jet carb is basically using the jetting adjustment you arrived at during your tuning process. Fixed jet carbs are used in many applications the majority are on small engines like lawn mowers. The jet size is calculated to give the proper air fuel mixture and I assume is tested on running engines throughout a range of conditions simulating humidity, air density (altitude), temperature etc. They apparently do not feel that adjustment beyond those parameters was needed and it must not have been or every time you would type in IH 404 carburetor in a search it would give you a flood of results about solving the problems of the non-adjustable main jet. I better put a link here to keep TV happy, I have no idea why the IH diagrams show a MS TSX 748 instead of the 827 you are showing? I do see your number is covered in the listing of applications shown under the YT replacement carb for your tractor. Assuming the 827 carb is laid out similar to the 748 in the diagram, have you actually had the jet part 19 in the link out of the carb to see if everything is clear down below it? I do not know if it actually sets way down in the hole below the nozzle part 17? If it does it looks like you probably need just the right screwdriver to get it out. And by the way just for giggles is the venturi part 16 installed that is a part that often gets misplaced? That can definitely give you the problem you are encountering. Also YT does sell a replacement carburetor that has an adjustable main jet.
CNHI IH 404 utility carb parts diagram
 
The fixed jet is just like what is in any Normal carb found on every car Pick up out there and like i said used mostly with the shut down solenoid off the out side of the carb found on many I H tractors . The jet is sized for max load . Now god only knows what all has been done to this carb and NO SPRAY carb cleaner will NOT eat out the nasty's . Been working on carbs 61 years . Ya want to clean a carb then ya need the stuff that we use and People that rebuild carbs us . The stuff that will take the hide off of you if you get a drop on you . A lot of people who do not want to pay the cost of the solenoid remove it when it stopps working as when this happens ya don't start the tractor as the pintal needle goes into the main jet and stops fuel from going thru . So if you don't have the solenoid then ya have a blockage in the main jet system that feed to the venture and discharge nozzle . I do not have the carb setting here inft, of me and it has not taken a hot tub bath in what i have to use . Also have you checked the intake for leaks or cracks???? Also is there a wire that is real close to the carb that is not hooked up to anything if so then this confirms my thoughts on the solenoid deal. . I H use them on all gas engines after 1963 and thus no main load screw. just a ideal either air bleed or ideal fuel mix used only for ideal adjustments
Now if ya were close i could make a service call . and then know what is going on .
 
Now that The greAt link poster posted the break down for ya your problem lies at the bottom of the discharge nozzle and main jet you have JUNK way down in the bottom and maybe also plugged, side holes on the discharge nozzle . And below that will lye a # 54-58 jet that can beremoved with the proper flat blade screw driver i perfer the style used for gun smithing , less chance of camming out
 
I read somewhere that it runs great for 4 seconds and quits. Seems to me like a little bit leaks in there as you prepare to start it, but its not getting in there fast enough to keep the engine running. You may have gas AT the carb, but I would like to see actually comes out of the bowl drain with the fuel tap on. Your fixed jet nor your float level have anything to do with your symptoms. If you have a decent flow out the drain then we can look elsewhere. But if you have a thin line of gas coming out the hole, or drips, then there is a supply problem. Plugged inlet screen, dirt sitting on the needle seat that is too big to go through the hole, or maybe the float arms are bent and the pontoons are contacting the sides of the bowl when you put it back together, not letting the float swing freely.
 
The Tractor Vet is correct, cars, pickups and even heavy duty gas burner trucks all have fixed main jets. The only adjustments were for the idle mixture. The difference is that road vehicles have economizer systems that lean out the mixture in light load and highway cruise parameters.
TV I am pretty certain his tractor did not originally have a main circuit fuel shut off solenoid that you keep trying to sell him. Neither the carb diagram, the wiring diagram or replacement carbs show it. I think that maybe that little 4 cylinder is not as prone to ..dieseling.. as the 6 cylinder I feel you are more familiar with.
 
No i am NOT tryen to sell him on anything . Maybe it did not come with it as i have NEVER worked on a 404 or ever bought one for resale . I have seen guys have one that stopped working just cut the pintal off and use the carcass to plug the hole , i have seen some pull it and stuff a main jet adjusting screw from and old M in them . I have had guys ask me how come they have run on after they do that . Sell nope if i am rebuilding one WITH IT and it does NOT work i will replace with new then. I don't even thing the three I H dealers that use to be close to even sold one . A 404 was not something that the guys around here had a need for or even want.
 

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