Antique Tractors Forum banner

Running issue, Help!

10603 Views 27 Replies 8 Participants Last post by  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 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.
1 - 6 of 28 Posts
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.
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.
Grizz said:
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?
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.
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.
Nice to know about the air cleaner. Forgot mine was low. I could not for the likes of me remember why it was that the engine required some choke to run correctly on idle. Put that little extra oil back in and voila, idles with out choke.

1 - 6 of 28 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.