dead ignition

[SONNY]

so as to not hijack the other thread I will make a new one.
IH 340 no spark to plugs,---in a hurry I borrowed the dist.,coil,resistor,plug wires and cap from a running cub, ( same dist.), after all that work the 340 is still dead!
Put it all back on the cub and the cub runs fine! WOT the heck is up with this picture!!!!!
I even ran a wire direct from battery to coil and nuttin. then I bypassed the resistor and still nuttin!
I have an allis C and a WD-45 did the same thing 4 years ago,---never did find out what was wrong and they are still out in the weeds!
GOTTA have my 340 to till with. I got about half done first time over and ran out of gas so I turned the key off, shifted everything out of gear and went in. Next morning I put gas in it and hit the started and choke and it turned over but never did fire. Got out the old spark plug tester and no flashes at all PLUS no start.
acts like the spark is at the points but wont go beyond that point.
I dont know why the total other ignition off the other motor wouldnt fire on this 340! --- cant shove it out in the weeds with the allis's cause I gotta till with it!

[Rodney51Cub]

Did you try different spark plugs or same ones ?

[Jim Becker]

I assume you have a 6-volt or 12-volt resistor required coil. Just as a wild shot, check the ground of the coil from the coil to the coil mounting bracket and from the bracket to the chassis.

If that doesn't fix it:
First, make sure the ignition points are OPEN and verify that you have voltage (6 to 8 volts) on both sides of the coil.
Second, make sure the points are CLOSED and verify that you have voltage (6 to 8 volts) on the ignition switch side of the coil and zero on the distributor side.
If it doesn't pass both those checks, fix it so it does.

Then check for a spark out of the secondary wire of the coil. If so, you have a problem inside the distributor. If none, you probably have a coil or condenser problem.

[SONNY]

checked all of that and it tested good. The other complete system should have worked on this one but didnt,---that is what I dont understand.
The 340 is a factory 12-volt system. The coils IH used on them have an external resistor in the system. voltage is good down to the points.
I tried the same thing on the allis's and same results, still no spark! dont know what I am missing!
looked on the internet but no help there!

[Jim Becker]

So you are saying the voltage toggles on and off at the wire from the coil to the distributor?
Are you saying there is no spark out of the secondary cable on the coil?

[Rick Spivey]

It sounds to me as if there is a problem in the circuit, as Jim is suggesting. OR, and this is a long shot, there is a mechanical problem where the distributor is no longer being driven, and just sits in one spot. I know on most IH tractors that is a very robust system, but just double check o be sure there is no mechanical issue with the distributor or its drive mechanism.

[SONNY]

shaft turns in BOTH dist.'s that I tried. Test light is out when points are closed and on when open. turn motor over with starter and test light flashes but no spark to the plugs at that test light, so that would be yes to both your questions, Jim.
I just knew the other system off the other tractor would work since it was of a running tractor, BUT it didnt work! THATS the thing I dont understand cause the COPLETE ignition system off running tractor SHOULD have cured the no spark on the 340. Cub and 340 have the same dist #'s on these factory 12-volt models.
I was running the 340 on the dist off a 504 and it has the morph offset bottom point on it. All the other IH tractors use the straight bottom point. 560, 706, 806, 574, cubs, 154, 185, 184, etc.
By going with the complete system I should have bypassed a bad part IF there was one, like shorted points, dead condenser, bad cap and wires, etc., but it didnt.
Jumper wire all the way back direct coil to battery didnt work either. even bypassed the resistor as a test and no go.
got me beat! I could use neighbors 706 and tiller but his wheels set out too wide and makes 2 very hard tracks in the garden on each 6' pass, ( tried it last year)!

[Jim Becker]

My second question was and still remains, is there spark AT THE SECONDARY CABLE OUT OF THE COIL. You keep answering that there is no spark at the spark plugs. That is not an answer to my question. Until that is answered, there isn't much else I can do to help you figure this out.

When you swapped with the Cub distributor, did you also swap the drive housing or just the distributor? In other words, did your swap include this part?

(Picture borrowed from TM Tractor Parts.)

By the way, the part number cast into the side of the distributor is the part number of the bare housing. There are different parts inside that give the distributors different advance. When you are done, be sure to put each one back on the original tractor. The Cub advances to 16, the 504 to 21 and the 340 to either 25 or 30.

[staninlowerAL]

JMHO, what Jim is describing is exactly what I experienced with my Cub, spark at the points when the ignition is on and rotate the dist shaft but no spark out of the coil or at the plugs. The coil was open on the high voltage winding. It took me a while to find it. Swapped the coil for a known good one and got immediate startup. Stan

[SONNY]

Sorry guys! now I am too confused to go any further on it. Had to go truckin today and didnt get much done, took meter and tested what I could and it all tests good,--according to what I was told by our ih dealer people.

[tst]

start at the beginning, make sure it has good compression and is in time

[SONNY]

Well I got ticked off and shoved the 185 dist on it again and this time it runs/tills for now. Have no idea what I missed the first time I tried it. I put it on,--set it by ear and tilled 4.5 acres with it.
I have NO idea about the advance thingy you guys are talking about so I am really confused on that subject. Either it runs or it dont and if its set by ear to the smooth running point and runs free, thats all I ever went by!
The dist that came on the tractor was junk,--- only ran on 2 cylinders, and choppy, so I put the 504 dist on it and it s been running super for 2 years! Smooth as silk, all kinds of power for the big tiller.
Looks like the one that came on it was from a junkyard and is in bad shape. At one point I was going to try to fix it but never had time to mess with it. I can tell it turns ruff, and a bit stiff. It might clean up, dont know what all is worn or broke in it.
I still loved the way it ran on the 504 dist! ---- anyway when I get the 504 motor back in I will have to fix it's dist. and use something else on the 340.

[Magnum]

I'm not sure about a 340 , but I just did the points gap on my super m and that was my problem with that tractor not running . I also did points and coil on my 230 , the new coil on the 230 was faulty , it would start when it wanted to , and never when it was warm . Both tractors had a large points gap for some reason the gap was over .050" or even more . Not sure if this will help you at all but our individual struggles seem very similar on this topic .