[DerickS]

The John Deere was running great until this weekend.....its a 1947 A for reference and runs good until I open the throttle wide open...it cuts out and starts black smoking. I have leaned out the carb and still have the same issue....when I hit bumps it cuts out and starts smoking black and clears out after it settles down. Does this sound like a float level issue or what else???? We got it painted and pretty and my little was enjoying a ride when this happened.....hard starting after that too.

 

[hawk4932]

Sounds like the carb to me. Last summer I had to rebuild the carb on my B. I would highly recommend the expensive complete rebuild kit. I think mine cost $103 from Steiners. But it comes with every single little piece. (EVERYTHING minus the body). I disassembled mine and then took the body to the machine shop and had it bead blasted. They only charged me $5 for that. The really important part is to clean out all of the small internal passages within the carb body. They are very small. Use shop air to confirm that you have them cleaned out. Prior to rebuilding mine I could turn the idle all the way in and back out and it wouldn't change anything. It runs great now although I still need to fine tune it more for a load.

On another note, based on what you mentioned, I would guess that you need new plugs right now. My B and my Neighbors A and 60 are all very finicky with spark plugs. Once they are fouled out they are junk. This is based on those 3 machines but I bet you will notice the same problem. Any other JD letter series guys have the same finicky plug issues. I can remember some discussions from the old ATF about specific brand plugs that seem to work better on the JD's. I use Autolites.

 

[hawk4932]

Hey Derick, you said that you got it painted now. Got any pictures? What does your little girl think of it now, better?

 

[DerickS]

Thanks for the info! I will be back up in two weeks to take the carb apart and start working on it....I have Autolites in but the number escapes me right now. We just painted up the parts that needed it to make it look nicer....she loves it now...until it quit running :lol:

 

[Peacher79]

Derick,
the Autolite hot plug # is AL3077 for the 7/8" threads plug.

Just another thought, is your gas stale? I started using Stabilizer a few years back in anything that doesn't run but every couple of weeks. It made a huge difference in my boat.

 

[DerickS]

Derick,
the Autolite hot plug # is AL3077 for the 7/8" threads plug.

Just another thought, is your gas stale? I started using Stabilizer a few years back in anything that doesn't run but every couple of weeks. It made a huge difference in my boat.

The gas was fresh...unfortunately I ran it out trying to get it running again! it was a mess this weekend, I'll write that plug number down Thanks

 

[Lovesthedrive]

Another question. Points? Or Magneto?

If points, did you look at the gap? I see what looks like a 12 volt napa battery in it. Did you remember to use a ballast resistor between the coil and the points? The ballast resistor cuts the amperage to the points so they dont fry so quickly. A bad set of points will sound like bad gas as well.

 

[DerickS]

Another question. Points? Or Magneto?

If points, did you look at the gap? I see what looks like a 12 volt napa battery in it. Did you remember to use a ballast resistor between the coil and the points? The ballast resistor cuts the amperage to the points so they dont fry so quickly. A bad set of points will sound like bad gas as well.

No ballast in line yet, I looked at the points and they were a little black but not burned gapped about 15 to 18 thou....should I run a 6 volt or wire the ballast in? Whats easier?

 

[Lovesthedrive]

The problem with running a 6 volt tractor on 12 volt. The 12 volt makes the starter pinion come out with such force that it will eventually knock the teeth off the flywheel. If you can live with that fact (someday to replace the flywheel ring gear), 12 volt is fine. Fortunately for me the 60 was made to run on 12. Yet if you are to run with 12 volt it is best to put a ballast resistor in before your points. On mine it is actually before the coil.

A ballast resistor actually does 2 things. It cuts the amperage, and drops the 12 volt to 9. Yes you get a hotter spark from the 9 volts as well over a 6 volt battery.

The nice thing about running 12 volt, you can take a jump start from a car.

 

[DerickS]

The problem with running a 6 volt tractor on 12 volt. The 12 volt makes the starter pinion come out with such force that it will eventually knock the teeth off the flywheel. If you can live with that fact (someday to replace the flywheel ring gear), 12 volt is fine. Fortunately for me the 60 was made to run on 12. Yet if you are to run with 12 volt it is best to put a ballast resistor in before your points. On mine it is actually before the coil.

A ballast resistor actually does 2 things. It cuts the amperage, and drops the 12 volt to 9. Yes you get a hotter spark from the 9 volts as well over a 6 volt battery.

The nice thing about running 12 volt, you can take a jump start from a car.

Wow, sounds like I should just get a 6 volt battery :shock:

 

[Grizz]

the spark plug issue can ussually be solved with Champions , D 16 is the normal heat range, D21 or D23 work well in play tractors that don'tpull loads for long period, NGK AB6 plugs can be a nightmare with point ignition. You might want to replace your points they dcould have a weak spring or bad pivot, point problems can minic carb problems if they only occur under power. And maybe change to a 12v coil or get a resistor which ever is cheaper if you are going to stay 12 volt. Not to start an arguement , but I have never seen starter drive or ring gear damage from 12V conversions, but now that it has been mentioned who knows?

 

[Lovesthedrive]

but I have never seen starter drive or ring gear damage from 12V conversions, but now that it has been mentioned who knows?

I can give you a link to the forum, against rules here for me to tell you where, so I wont. But it is real common problem on the 420c's (crawlers). Lavoy has seen "his fair share of damaged ring gears". Maybe its a prob with the 420c?

 

[Grizz]

It might be a problem on some tractors, I have just never seen it, 12 volted quiet a few oliver 88 s abd 2n / 8n fords without any problem, but I have heard that flathead ford V-8 s wreck the sratrer drive even at 8 volts. just cause I haven't seen it doesn't neam it isn't a problem.

 

[DerickS]

Thanks for the info guys I have access to a new 6 volt battery that I will swap in just until I get the possible carb issues sorted out...if that 6 volt solves the problem then I'll know it was baking the points I guess :? Thanks again I will let you know after next wekend when we'll be up by the tractors

 

[DerickS]

Thanks for the info guys I have access to a new 6 volt battery that I will swap in just until I get the possible carb issues sorted out...if that 6 volt solves the problem then I'll know it was baking the points I guess :? Thanks again I will let you know after next wekend when we'll be up by the tractors

Took her apart and found nothing I can see....still puffs black smoke and wants to stall going up or down hills and hitting bumps :?

 

[Lovesthedrive]

How is the fuel delivery? Remove the fuel line and let it flow into a can. Does it flow at the same rate? Is there a strainer on the carb? Does the strainer need to be cleaned?

If it runs normally yet starves after running, that tends to be a fuel delivery.

 

[DerickS]

How is the fuel delivery? Remove the fuel line and let it flow into a can. Does it flow at the same rate? Is there a strainer on the carb? Does the strainer need to be cleaned?

If it runs normally yet starves after running, that tends to be a fuel delivery.

I put on a good fuel bowl and cleared the lines and fuel runs smoothly from it, are you talking about the screen thats on the top of the carb when you access the top of the needle and seat area?

 

[Lovesthedrive]

yup, anything that impedes fuel flow can make it hiccup after it is going. Low float level will do the same.

I saw a video on Youtube where a float level was checked while the engine was running. The drain to the carb had a clear piece of tubing attached. As the engine was running and under load they were able to see where the fuel level was.

http://www.youtube.com/watch?v=HOaDJyGOsBQ

 

[DerickS]

One thing I forgot to mention is that while idleing sitting still the govenor is working like mad....whats the problem there? Can a total JD novice like me take this carb apart and get it right or do I need to send it somewhere?

 

[Sailor John]

Derick, of course you can dismantle your carb. Black smoke shows you have too much fuel or too little air. Air is easiest to check so start there. Make sure that the choke is staying off, not by looking at the linkage but take off the intake and look at the choke butterfly. Fiddle with it and see if it is being held open or could it flutter closed. Start it and watch. Go through the entire air intake system looking for any possible blockage. No critters?
If you decide to dismantle the carb you will need the correct tools, those that fit properly. The trick is to look . Then look again. If you need a diagram or pictures, make one, make lots. Remember that you are trying to locate a fault so look closely at everything as you dismantle. Use a magnifying glass if necessary.
For a jet to cause your problem it would need to have fallen out.
The other possibility is that there is an air bleed blocked but they are big holes and easy to check.
Only after a thorough inspection can you blow out all the orifices, clean the parts, blow it out again, and reassemble.
You'll be fine.

John