John Deere A Carb

[ffdfireman18]

I bought an A multifuel tractor that the tanks were out and was just ran off gas from the big tank. My question is--is threre a differant carb for dual fuel tractors and gas only tractors. I"m trying to peice this back together again to run on the multifuel. Thanks for the help.

 

[DScott]

The late model As were available as either All Fuel or Gas tractors. The All Fuel came from the factory with a DLTX 72 carb and the Gas version came with a DLTX 71 carb.

 

[Husker44A]

What carb do you have? A dltx 53 is an all-fuel carb. Yes there is a gas carb. If you want to keep it original stay with the carb you have IF its an all-fuel carb. I Have a 44 A hand start with the dltx 53 and it works very well but you have to keep them clean. If you have the carb apart I suggest you clean the passages before re assesbly.

 

[ffdfireman18]

Thanks guys. Its says DLTX18 on the side of it. He said it was just rebuilt, and it runs good. There was another carb I got in a box of stuff, but I think it may be a parts carb. I'm not sure of the number on that one, but I do know the mounting flange was broken quite badly.

 

[DScott]

What is the serial number of the tractor you are working on? The DLTX 18 carbs came on the unstyled tractors (which were all All Fuel) and since you were asking about gas tractors I assumed it was a later model.

 

[ffdfireman18]

558344 is the serial number. Like i said It was running, but there were a bunch of things that came with it. Some might be for that tractor and some was just junk. I appreciate the help.

 

[DScott]

(quoted from post at 10:01:37 05/18/11) 558344 is the serial number. Like i said It was running, but there were a bunch of things that came with it. Some might be for that tractor and some was just junk. I appreciate the help.

The Gas Model As started at SN 584000. So, your's came from the factory as an All Fuel tractor with a DLTX 53 carb on it.

 

[ffdfireman18]

OK thats that helps. Do you know what the dltx18 carb is? is that a gas only or all-fuel? And then I guess I need to look for a 53 carb.

 

[ffdfireman18]

Sorry I see the 18 is on an unstyled A.

 

[DScott]

(quoted from post at 10:48:44 05/18/11) Sorry I see the 18 is on an unstyled A.

The DLTX 18 was used on SN's 425851 - 487999 unstyled model As which were available only as All Fuel tractors. The DLTX 18 is a common carb and will fit/work on all of the As but pulling performance on your late Model A will probably not reach it's full potential if you use the DLTX 18 in it's stock configuration.
If it now runs good enough to suit your needs and you are not concerned about correctness, then there is no problem running the tractor with the DLTX 18 carb.

 

[Mitch D]

So what is the main difference in a 71 vs 72 to burn allfuel or gas?

 

[DScott]

(quoted from post at 11:13:27 05/18/11) So what is the main difference in a 71 vs 72 to burn allfuel or gas?

The only difference that I am aware of is that the 72 uses an economizer plug and the 71 does not.

 

[Kurt_JDB]

The main difference is that the compression ratio of the all-fuel is much lower than a gas tractor. This was achieved by using low compression pistons. A different manifold was also used. The all-fuel manifold is a cast iron monster designed to transfer heat from the exhaust side to the intake side so as to keep the incoming fuel air mix hot.


Kurt

 

[Anonymous-0]

To add to what D Scott says above and to give you a bit of an expectation or comparison....

I have two early styled A's. One is a very late long hood the other a bare bones cast frame, steel tag hand start war tractor. Both have all fuel pistons in them and are in very good condition inside. The long hood has the correct DLTX 53 carb on it. The older one however has a DLTX 34 carb from a B! Was that way when I brought him home after a ten year rest in a western Ohio fence row and I've never changed it.

When it comes to driveability and using it to mow with the #5 mower, plowing with a 4B plow, pushing snow with a 7' blade or pulling a 7' drag disc.... Can't tell a difference between 'em and the old tractor actually is generally easier to start though I think that is more related to the X mag versus the C on the long hood. Yes I use those dreaded Champion plugs too thouhg always the D 23.

When I hook them to my dyno, the old A runs about 3 HP less HP than the long hood and its governor response is not quite as snappy as on the long hood.

The difference between a DLTX 18 from an unstyled A and the correct DLTX 53 will likely NOT be noticeable! Possibly not even on a dyno and definitely would be tough to notice in the seat!

So it depends most on how exacting you want to be regarding "correctness of parts" more than the way it will likely behave and operate.

Hope that helps some.

Later.

 

[DScott]

buck eye al,
That's good to know, I have never had two similiar As with the different carbs together at the same time to really compare them. I figured th All Fuel carb would run rich since it was designed to handle the heavier fuels. It would be interesting to get a good running tractor, a couple of different carbs and put them on a dyno to see what difference it made, if any.