a Jumps ign. timint

peteellis1 · May 4, 2016

on sudden stoppage of farmall A it often will jump timing so we have to change plug wires 180 degrees on dist. cap. is there a spring on the front end of that shaft that allows timing gear to change.

tn terry t · May 4, 2016

I bet the dist. drive has stripped out I have had a couple to do it before

old · May 4, 2016

Can not say for sure on that one but I have a 340 that did that type of thing and the distributor drive gear at the bottom of the distributor stripped out which would let it jump timing and I like to never figured out what was going on. Took a distributor form an H I have and that fixed it

gene bender · May 4, 2016

There is a spring but it will not allow the gear to jump time must have some teeth gone you need to pull the gov housing then you can remove that gear. Before you remove the gear have some help and turn the engine over with a crank slow to make sue the cam isnt missing teeth. I t will be easier to turn engine over if the plugs are removed. If teeth are missing on cam gear you have another problem removing that gear requires removing radiator and crank pulley which requires removing steering assy so the crank pulley can be removed then front cover can be removed and cam gear replaced.

Badger bob · May 5, 2016

I have a B that the thing just stopped. as gene says I bet the gear is missing some teah. Bob

BarnyardEngineering · May 5, 2016

It jumps "180 degrees" out perfectly every time? That seems unlikely. A missing gear tooth is going to pick back up in a random location, not perfectly "180 degrees" every time.

How does the tractor run normally? My thinking is that you've never been running on more than two cylinders, ever. It's way down on power so easy to stall, then difficult to restart. You swap the wires 180 degrees, which fixes two cylinders and breaks the other two. Then by a stroke of luck it just happens to start.

If everything is timed properly, the #1 (front) plug wire should be connected to the upper right tower of the distributor cap as viewed from the driver's seat. Then #3 (second from back) should be connected to the lower right tower. Then #4 (back) should be connected to the lower left tower. Then #2 (second from front) should be connected to the upper left tower.

john *.?-!.* cub owner · May 5, 2016

Do you have a magneto or a distributor?

peteellis1 · May 6, 2016

thanks all comments about timing trouble is engine runs great and full power before and after chang in timing

pete 23 · May 10, 2016

I see it has a magneto and not battery ignition. The only thing that would cause it to jump 180 degrees each time it occurs and is back in time by changing wires 180 degrees is the small gear that drives the rotor. It has a flat spot in it and on shaft that drives it. Magneto turns engine speed and that gear reduces rotor to half engine speed. It has to be slipping on that drive flat and re-engaging again after shaft makes one turn. I would check that and just put a shim to tighten that gear a bit to prove or disprove my diagnosis. A lot of those covers are installed wrong when someone changes points and does not orientate himself when he take the three screw cover off and then you have same problem with 180 off.

a Jumps ign. timint

peteellis1

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tn terry t

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old

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gene bender

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Badger bob

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BarnyardEngineering

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john .?-!. cub owner

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peteellis1

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pete 23

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