Farmall B - No spark

I recently took possession of my great
grandmother's 1941 Farmall B. It had sat a
few years without being used. I changed
the oil and filter, cleaned sediment bowl,
drained old gas and replaced with fresh
gas,changed spark plugs, and replaced the
battery. It cranks over nicely but doesn't
fire. I pulled the wires and checked for
spark but nothing. I am looking for the
wisdom of the forum geniuses to try and
help me get my great grandmother's tractor
prowling the earth once again. Any
suggestions are greatly appreciated.

Do you have spark at the points? If you do problem is either in the cap, rotor or condenser..others will chime in. Good luck..

First check to see if you have power to the coil, if so points in the distributor are probably dirty. Clean them and see if you have sparj.

Thank you for your reply. I failed to mention in my original post that I have very limited mechanical skills. I am able to do things as long as someone lets me know what to do. How would I go about checking for spark at the points?

The most frequent issue with no spark is that the points under the distributor cap have corroded just enough to not allow them to pass current for ignition. The remedy (first fix) is to use fine emery paper to polish them. This is followed by cleaning them with a folded dollar or other bank note. these are lint free and will clean the freshly polished contacts. if no joy, make sure they are opening correctly to .020inche. Next it is necessary to determine if there is voltage getting to the points. A test light (auto store) that works on 6 or 12 volts will help this. With the clip of the test light attached to shiny metal, the bracket holding the coil will do well, touch the small coil terminal not connected to the distributor. this should show voltage by lighting up. If the points are closed, there will be no voltage on the distributor side of the coil. If a piece of a plastic spoon is between the points to insulate them, there should be voltage there as well. If no voltage or light at either side of the coil, the ignition switch or a wire ic likely to be the issue. This site sells ignition switches if it is bad. (out is run, in is stop) and If you are totally out of the loop on how to do this watch a video on installing points. You should not change the condenser. It is likely just fine.
Do not leave the ignition switch on for more than 3 or 4 minutes if it is not running. To get points or other components of the distributor, use the info on that riveted on plate on the body of the distributor. It is not a standard distributor made by IH so points for that model tractor will be wrong. Jim

remove distributor cap. get the points on the low lobe. snap them open with a screw driver you should have a spark at the contacts.if not remove the points and file them with a point file or run a piece of emery through them. set them after cleaning them. gap should be .020 pretty sure this delco mag uses the same setting as the ih dist. you need the points on the high lobe to set the gap. i sure notice now no one has any idea on a carburator, or points setting in a dist or mag. its getting to be a lost art just like the 2 cyl john deeres. one of the most dependable units in an engine and its getting lost. talking with a young guy here who bought a super w4 and he is just amazed that i know stuff. you gotta show me all this he says. he saw me start my w4 with a half turn of the crank and wants his starting the same. i said yes it needs my touch.

first check for battery voltage at the coil. Then remove the cap and clean the points after setting sometimes the points get a film and will not spark so clean them and check you should have spark then as setting around things dont burn up

Something you might want to do at some point is to remove the coil and the cover behind it and renew the dried up grease in the little gearbox that drives the distributor. I have seen them dry and rusty and the gears worn out from no grease and the distributor not turning.

If you work through my Ignition Troubleshooting Procedure it can help find the cause of no spark. One typical common problem IS THE POINTS ARE BURNED PITTED OT NOT GAPPED CORRECT.

VERY FIRST THING TO TRY IS TO CHECK AND CLEAN THE POINTS. If burned or pitted a points file is a band aid fix but if only gray oxide coated running a dollar bill through them may get her going.

Get a simple test lamp or a volt meter out and try my procedure, post back any questions

http://www.ytmag.com/cgi-bin/viewit.cgi?bd=farmall&th=5745

John T
John Ts Ignition Troubleshooting

Thank you everyone for the suggestions. I will give these ideas a try this weekend. I was also thinking of running some new wires. Would anyone be able to tell me what gauge wire to run? The existing wires are pretty rough. I am also putting on a new ignition switch. Thanks

Please don't fix anything until you find out what is currently wrong!!!!! Then fix that to get it operational. Patients sometimes demand antibiotics when the issue is a virus. Diagnosis is the primary tool. Replacing components is a sure way to add uncertainty to a uncertain situation. You can replace one component at a time to make it more reliable, but only after it is going. Jim

Thank you to everyone for helping. My b runs like a charm. Many thanks to all