Older Farmall timing revisted.

Last week I had a thread going on timing the distributor on my '45 BN.

If I had it timed by the book it has a skip at hi-idle, when I retarded the timing a bit the skip went away. I sort of hated to retard it as I know that can cause things to run warm and I was planning on working the tractor hard (plowing) that week.

So I set out to the field with the timing set by the book with a skip all the way there. As soon as I got on the governor the skip goes away, 7 hours of plowing and never a skip (well, sort of, read below) under load. Then it was just a light drive back home, again with the skip.

I guess the tractor just likes to be worked...

Now a little story. First off my BN has a 187-BN 16" plow, which in sod that hasn't been touched in many years was giving the old girl a good workout. She walked great in first but really need the extra speed of second to flip the sod over, third worked but was really to much for the conditions. Anyway, about 3/4s of the way though the job my BN started to spew black smoke, lost all power and then stalled. I thought something really bad had just happend, the engine while running strong all day is a bit worn. I hit the starter rod and it didn't start and seemed to be spinning pretty fast. I jump off the tractor and see gas pouring out of the carb.

So, I go home grab a carb I had on my bench waiting to be rebuilt and was back in business. I haven't pulled the bad carb apart yet to see what was going on but my guess is the float must have a pin hole in it, I can't imagine the needle just all of a sudden going bad.

I have to admire farmers that used to make they living with these machines. Plowing in heavy ground with a small tractor is definitely a "involved" job for the operator. Better then a horse though!

K

Sounds like a day on the farm. Glad ya got er back up and runnin'.

The other thing to think about with that miss. I can't recall from the other thread if you ever said at what speed you were noticing it, but that can be a drawback to a mag (the only one I can think of, actually), in that it is either at TDC or full advance, no in-between variable advance like on a battery igntion distributor, so it will run better at full tilt than at lower rpms.

Sounds like she was working well, though.

It's a distributor, not a mag.

It did run well when being worked though.

I'm thinking there might be just enough slop in the system that it runs this way. I wonder if a pertronix system might help put some, I've heard they can help with worn distributors.

K

Two ignition things possibly connected.
If the advance mechanism in the distributor is rusty, or broken, it will run as noted. It is simple inside, To test quickly, but not for sure, rotate the rotor CW with your fingers, it should move with modest force. It should rotate 15 degrees or so then spring back. If it does not, or will rotate 15 degrees either way and stays there it needs attention under the breaker plate.
Second thing: if there is noticeable play in the rotor shaft (sideways in any direction, not in the direction the rotor is pushed on) it needs to be rebuilt. Play here results in wild timing changes, and missing.
If there is a intake manifold leak, or a really bad intake valve guide, the engine will also miss under idle conditions. Use propane from a small torch with the tip removed to find a leak like that (do it outside, use a small opening on the propane knob, and move the propane around the manifold and manifold gasket at the head to ad fuel to the leak. It will quit missing as soon as the leak gets fuel. If this is unsuccessful, se which cylinder is missing, by pulling one plug wire off at a time (insulated pliers are a must) if you find it, change plug location, and see if the miss follows the plug. If so put in new plugs. If it doesn't, check the valve adjustment. .020" cold all valves. Good luck, JimN

Thanks for the info.

I did check the distributor shaft and is has very slight play, just enough that you can notice it. I'm not sure what you would consider normal, it's not sloppy by any means. I'll try the advance, never thought of turning it by hand

Everything else I've tried. I just did a head gasket a little over a week ago so it got all new manifold gaskets and the valves were all set (.14 hot) and doubled checked. The plug wires are pretty new, as are the plugs. It ran the same way with the old wires and plugs too. It also has a newish points, condenser & cap, non of which got rid of the skip.

It's not a constant skip, it's a every so often skip. I think if I was loosing a cylinder all together it would make it a lot easier.

Retarding the timing a bit does help though.

I can try the propane trick though, maybe there's something up with the manifold.

Thanks,

K