I need some help with a buddy of mines tractor. he has a mid '50's Massey T020 that has a Marvel Schebler carb on it. He was telling me that it would not run without the choke pulled out. When he bought the tractor, the fuel tank was rusty,so he took it and had it cleaned,they also installed a inline filter. Now to my problem. I tried to adjust the carb, that didn't help. So I pulled it off and took it apart. Float bowl was rusty,and there was some trash in the idle jet,as well as in the nozzle air holes.The high speed jet was also plugged up. I could not get the high speed jet out of the body of the carb to clean it, so I blew compressed air through it and got it clean ( I think!!!!). Now I can make it idle very nice, but to get it to go to high speed, you still have to pull the choke out. It runs really well like that, but it isn't right. So does anyone have any suggestions? the only other thing that I can come up with is to try and hand drill the high speed jet out a little bit, which I am holding out as a last resort,but I am out of ideas. Any help would be much appreciated. Thanks Heath
I'd say you still have some debris or varnish build up in the main jet, especially if it's a brass tube type jet. One thing you could try is from NAPA. Get a gallon can of Mac's Carb Cleaner, take the carb apart again, and soak it in this stuff for a good while. It's a little expensive, but it will disolve the gunk that builds up in the carb. Just make sure you don't put any rubber or gaskets in it, it will eat them as well. Just a thought.
Look up Roberts Carb Repair if you need parts. If I remember correctly they are in the midwest. I rebuilt my Marvel-Schebler carb on my 1956 JD 420 crawler with his parts after a good cleaning and she runs like a champ.:usa
there is a slide in the throut you will not see if you are not looking for it take it ouy and clean put back the same way you took it out ,that is a up draft carb so it need suction from the intake so make sure all of your gasket are good and cant suck air,and when you are adj. the carb hook up the air cleaner or you will not get good suction and you cant adj carb right.hope this helps alley
try to take out the high speed jet after soaking the carb in the cleaner. it should be taken out as debris is sometimes on the outside and there may be cross holes that need to be cleaned in the main brass jet. patience is a virtue when working on carbs and if you mess up the high jet, parts are available. napa is a good source for rebuild kits if you have the numbers from the side or tag of the carb. be double sure everything is cleaned out of the carb. the cleaner solvent is reusable but keep it closed as that stuff stinks and evaporates quickly but it workd really well. good luck.
If you are looking for parts or a rebuilt carb look here. http://www.ytmag.com/cgi-bin/store/model_parts.cgi?SearchArea=**&&md=TO20&cat=Fuel System / Air Intake&r=mcats http://www.ytmag.com/cgi-bin/store/show_modelcats.cgi?SearchArea=**&md=TO20&cat=