McCormick-Deering 10-20 Carburater guidance

Now that I have my rubber bands on my tractor, I can attempt to pull start it since I have ruined my elbows trying to crank it.

I took apart the sediment bowl and carb today. The new sediment bowl did not work properly so I got an old one and cleaned it out and it works great.

I took apart the carb as well. I need some guidance on these operate. Forgive my terminology and correct me. I took apart the inlet bowl. I have a good float and it seems to move freely. I have the pointed end of the needle pointed up. It bolted down tight and does not leak.

My carb is clean and all little holes in each piece seem clean. I bolted down the upper carb lid onto the top of the three carb sections. The top air mixture turns nicely. I put the mid and bottom sections and bolted up the carb tight.

After putting it on and tightening it up, I turned on the fuel. No initial leaks. Finally, after leaving the fuel on for some time, fuel was dripping from the copper line that leaves the upper chamber to the mid chamber. Is this where the fuel should enter the carb. It would appear that the float is not able to shut the flow of fuel. Is this correct?

I think this is also going on with my other tractor so now I need to learn the details of the carb. The fuel drips into the mid section from the copper tube and loads up the carb and backs up into the air intake.

At the end of the long day, I did redo the timing, spray a bit of starting fluid into the carb and got a nice fire on the first pull. I think if I get the carbs working better, I'll have these two gorgeous tractors running well soon.

Thanks for any help teaching me the carb and ideas on what to try next!
Dave

Dave, I am right with you same problem. I have been chasing water problems around on my 10-20
Head I think I got them all. I have had this tractor started with hand crank 3 weeks ago, But have not been able to do so now, it pops and fires after sitting but than floods. I pulled the air mix screw out of bottom of carb and watch for fuel leaking. Pulled cork and install a recoatsed one. Took out needle valve and put valve grinding compound on it and relapped it into seat put it all back together and leak seemed to stop. When you put your needle back you need to turn carb upside down so it goes in the chamber and also upside down to measure your
floot level. If your floot will not shut off the gas flow it will run right into the manifold
and when you crank it the gas floods the plugs
and it will not start. oldiron29

Dave-Have been admiring your work, and would like to help. I don't have a 10-20, but the carb would seem to be similar to our 1927 Farmall Regular, or 1925 15-30. If fuel is dripping through the copper tube, then I believe that your float is not stopping the flow of fuel. I think the copper pipe is more or less of a vent pipe, for the fuel bowl. Your float is probably cork. If it is not new, I would consider getting a new one. Old ones can get soggy, and too heavy. I have let them dry out, for a long time, and coated them with shellack, and have had that work. Also, if you can see fuel running through that copper vent tube, then you probably have the tube to the air cleaner removed. Our 15-30 won't run with that tube removed. Must need the resistance of the air cleaner to draw the fuel through the carb. Sometimes a float will hang up, and you need to tap on the bowl, to free it up, and keep the carb from running over. Hope some of this helps. Lots of guys on this forum know more about these, than I do. Hope to see your tractors at the Cedar Valley Engine Club show.

Your needle valve must be a smooth surface where it seats as well as a nice smooth surface in the carb housing where the needle valve seats down. The biggest problem with these carbs is the WRONG float setting. DO NOT use the setting provided in the carb kits. those settings are way wrong and will cause flooding and running problems like crazy. The correct setting is right in the fuel bowl and is a machined groove that goes all the way around the inside of the fuel bowl. Set the float to that line and it should run great if the suction tube is in good shape. The mixture adjustment is the knurled knob on the top and must have the little spring to keep it in place or it will vibrate and change the setting. The copper tube is nothing more than a fuel bowl vent and if it is leaking fuel into the air intake, the float is set wrong, or the needle and seat are not clean or making a good seal due to wear.

Bob - I have three carbs and all of them have a pointed end and a flat end of the needle. If I remember correctly, when I took them apart the pointed end pointed up into a tapered groove. The flat end seemed to match the mark left on the float bar.

Dave-Have been admiring your work, and would like to help. I don't have a 10-20, but the carb would seem to be similar to our 1927 Farmall Regular, or 1925 15-30. If fuel is dripping through the copper tube, then I believe that your float is not stopping the flow of fuel. I think the copper pipe is more or less of a vent pipe, for the fuel bowl. Your float is probably cork. If it is not new, I would consider getting a new one. Old ones can get soggy, and too heavy. I have let them dry out, for a long time, and coated them with shellack, and have had that work. Also, if you can see fuel running through that copper vent tube, then you probably have the tube to the air cleaner removed. Our 15-30 won't run with that tube removed. Must need the resistance of the air cleaner to draw the fuel through the carb. Sometimes a float will hang up, and you need to tap on the bowl, to free it up, and keep the carb from running over. Hope some of this helps. Lots of guys on this forum know more about these, than I do. Hope to see your tractors at the Cedar Valley Engine Club show.

Loren - I'll be at the Cedar Valley show. Al Koenigsfeld is my uncle and I designed the www.restorerosevillestore.com website for the store. I was going to drag these old tractors to my farm for looks but Al suggested restoring them for the show at Roseville. I just need to get them running consistent now.

My float looks like a new dry cork that has been varnished. I guess I will spend more time testing the float with the carb on the bench. I was guessing the problem was this.

You are spot on, I have the air tube off. I also am not running any oil in the air cleaners. Would this also cause some air intake issues. I did this for two reasons. My originals where completely shot and we remade them for looks. I also thought I could give the motor a little shot of starting fluid to help it fire.

Look me up at the show, I will be the guy trying to get two 10-20 to fire. I will take them either way because I know I will find a group of guys to help tune them if I don't have them ready.
thanks for the help.

this is my problem. I will try the compound and really work the float over on the bench and try again. I needed to make sure that fuel was not supposed to come down the copper tube. Now I know that the needle valve is not seating enough to stop the fuel.

thanks,

Hi Dave, The angle of the needle valve seat must be different than the angle on the tip of the needle valve for it to seal. I have had luck burnishing the seat with a drill bit running backwards with very light pressure and lift the bit while it is still spinning. Sometimes the tiniest bit of dirt or corrosion can cause the needle valve to seep and flood the fuel bowl. The machined grove I was talking about is on the inside of the float chamber and looks like a machining error when they were smoothing up the fuel bowl casting, but it is acually the float setting line to be used by the assembly guys and IH mechanics. Funny thing is, I never found a printed reference to that mark, but all the carbs I have have that line inside. When I rebuilt the carb on my 10-20, I first used the setting provided in the kit and man did I have problems like you are talking about. When I noticed that line inside the fuel bowl I thought, why would they make that same mistake on all of these carbs, well It turned out to be no mistake and that line is there for a reason. I set the top of the float to that line and she fired up right away and ran like a top afterwards although I did have another problem develop after I ran it a while and that was there was a dried drip of sealant on the cork float that hung up on the fuel bowl side once in a while. I took a fine file and dressed up that drip and not one problem after. I got many compliments on how nice it ran. Several old timers who farmed with 10-20s back in the day said it was the nicest running 10-20 they ever heard. One more thing, there are only a couple gaskets used on those carbs. One for the fuel inlet housing where the filter screen is and one to mount it on the intake. If you used a gasket anywhere else, it will change the highth of the suction tube and mess things up slightly. Don't worry about leaks happening, if the float is set right, the top of the fuel bowl cover to bowl will only seep some if you get on really rough ground and very little at that since the float seems to act as a slosh baffle. If you have more trouble, send me an email and I will talk you through it over the phone.

great info Bob. I will take some time and really look at the needle seat. Thanks for the phone call offer. I may just take you up on it! I would love to get these two running as good as they look.

Dave

Bob - do i use the top of the float at the line or the bottom of the float?

Top of the float at the line.

Bob - THANK YOU THANK YOU THANK YOU. You were absolutely correct about the needle valve but you knew that. With my abundance of carb parts, I found two needles and float combinations that worked well. I tested each one on the bench using water to fill the float bowl while holding my finger to plug the bottom. It took me a few attempts to find a needle/float and the part that the needle seats into before I had the right combination. One of the carbs that leaked the most was a professional rebuild. Anyway, no carb leaks now.

I tried to pull start the 1925 on steel. Got some pop/backfires and nothing else so my timing must still be off. I will copy the settings from my 1927.

I pulled started the 1927 and ran it for two hours. It galloped just a bit but when I took a steep hill, the governed kicked in and just powered up the hill perfectly. Drove it about 2.5 miles and let it idle for long periods. THE CARB NEVER LEAKED ONCE!

THE BEST PART: I backed it into the garage and killed the motor at low idle and fully retarded the mag. I set the idle up, 1/2 on the timing and it started on the first pull. I idled it and killed it four more time and restarted it!!!!!!! Thank You. I shut the fuel off and the carb didn't leak!! Tonight, I will try to crank start it and see how I do!.

Yeahhhhh!! I knew you would get it done! I remember when you first posted the pics of those ol girls when you got them a few years back. My old 29 10-20 didn't look much better when I got it.

I didn't get it to start later in the day....BUT I primed it and did a full choke. It fired on first pull but didn't start, then I smelled gas so must have flooded. No comes the part of learning how this old machine wants fuel/choke and all of that.