JD Unstyled B carb issues

[Mark in WV]

Have a DLTX10 and tractor wouldnt run unless the load needle is open...wont run on idle valve only...So I have taken it apart and cleaned it out...some of the brass plugs are stuck and cant be removed....backfires and wont idle, but runs ok under lite load or at higher rpms. Any ideas???

 

[Kurt_JDB]

Sounds like you have a clogged idle passage in the stem. There is a so called "secret" passage in the stem behind a brass plug. It is smaller diameter than the bore for the plug, so it is easy to use the wrong size drill bit when cleaning it out.

The way I go about getting all the plugs out (thanks to FIT for this idea) is to build a nice charcoal fire and lay the carb body in the coals and leave it there "till the next day. The plugs will then turn right out and even the nozzle may fall out.

After you have all the plugs out use aircraft size number drills -BY HAND- to clear out the rust from all the passages. A place like Roberts Carburetor can sell you the right size drill bits.

You can get the nozzle out of the stem by running a tap into it, and then put a piece of threaded rod into it, and using some nuts "n washers make yourself a little slap hammer to draw out the nozzle. I forget the tap size off hand, but you should be able to figure it out by seeing what is the largest number drill that will fit in the end and then look at a tap chart..

Good luck!

Kurt

 

[John T]

Been there done that..Shes never gonna run right until you remove those brass drill plugs and use the No 40 and No 53 extra long aircraft drill bits (got mine from Roberts Carb) to drill out all the passages behind them. If you heat the plugs just till they start to give off that funny off (green/blue/aqua) color and then stop n let em cool they usually come right out. Id also remove the vertical center bore nozzle and clean all its tiny holes along with the side economizer plug.

John T

 

[Kurt_JDB]

That sure is a nice lookin' carburetor John T. I'm about to start putting the engine back together on my "basket case" 1938 B. Hope to get mine lookin' that nice.

Kurt

 

[Anonymous-0]

Popin John fixed mine that I was sure was junk.

 

[John T]

Thanks, A long time ago I had Roberts go through it then later I did it again and installed a lot of the new Brass components you see and re drilled the passages and worked on the economizer after Duane Larson heard it and advised it needed more cleaning.

UNFORTUNATELY its kind of gummed up n varnished again despite my use of Sta Bil and two cycle oil for years when it sits 9 months at a time. I need to go through it and remove n clean the nozzle since for the first time in several years (always started first or second pull every year) she failed to start last week and I traced it down to a carb problem. Oh well, sittin months at a time is soooooooo hard on them

No rest for the wicked I guess

John T

 

[PopinJohn]

Carbs that are put in a fire to heat the brass plugs usually wind up with the tension gone out of the detent springs and balls for the idle mix and load mix needles. Then they have to be dug out and many times the detent ball can not be staked "just so" for the ball not to fall out if you happen to remove a mixture needle for some reason. I use a small mapp gas torch to heat each brass plug individually, and sometimes if you first try to tighten the plug just slightly, it will unscrew with no problem.
MikeS.

 

[RandyB(MI)]

Good advice Mike. Guy could have the thing all rebuilt by the next morning when the fire pit is cool. Maybe 30 seconds per screw? I don't understand.

 

[Kurt_JDB]

Well, Mike, that"s a decent precaution. I haven"t had that problem myself in the 6 or so carbs I have put in the fire, but I see your point, and i"ll give your method a try on the next one.

Kurt

 

[Mark in WV]

I was thinking of sending mine to Roberts Carb....Who is Poppin John???

 

[PopinJohn]

http://www.popinjohn.com

Mike Shelby

 

[Husker44A]

7/32" drill bit.......1/4"-20 tpi Tap.... 1-1/4"x 2 1/2" bolt, 2-1/2" flat washers, 1-1/4"flat washer , 1 1/4 " nut. This is what I used. Also, works great for pulling stuck rifle shell cases out of the reloading die. Lay the 1/2 " flat washers on the carb stem then stack the 1/4" flat on top of the other washer. Install bolt stug after drilling and tapping. Thread the nut on the bolt install the bolt in the carb nozzle. Once seated tighten the 1/4" nut. Out the nozzle comes !!!