Lost Spark in 753

[Mike'sHorseBarn 2,650]

So I went to move the 753 a few weekends ago to go to a show and no spark. Weird seeing as though it was purring like a kitten 3 days before. Oh well stranger things have happened. So I was thinking it was the coil because it has new points and condenser and ignition switch. So I replaced the coil and I had 12 volts going to the coil. I made a new spark plug wire. Still nothing. Hmmm. Grabbed the end of the spark plug wire and turned it over to see if it would shock me.....nothing so it wasn't the plug. What the heck am I missing? I decided to tear all the old wires out and make new because it did have some wires in need of replacing. The amp meter quit working too, but that wouldn't cause the loss of spark would it? Also, I'm not sure if this was the original amp meter or not. 

 

I'm just sort of scratching my head on this one.

 

[953 nut 51,650]

10 minutes ago, Mike'sHorseBarn said:

new points

New or not, clean them and I bet you will be up and running.

[WHX?? 46,736]

Definitely not the original ammeter Mike but  does look cool .. not something stupid like bad new points or coil?

[WHNJ701 4,164]

I am sure you have had the same horrible humid air all summer we had in nj, check those points 

[Mike'sHorseBarn 2,650]

26 minutes ago, WHX20 said:

Definitely not the original ammeter Mike but  does look cool .. not something stupid like bad new points or coil?

 

Could be, I have more points here to try, but based on previous answers I'll be cleaning what's there. 

 

13 minutes ago, jabelman said:

I am sure you have had the same horrible humid air all summer we had in nj, check those points 

 

We did have ridiculous humid weather all summer and had points trouble as a result on two other tractors. 

[WHX?? 46,736]

More stupidness Mike bad new condenser?

[Mike'sHorseBarn 2,650]

11 minutes ago, WHX20 said:

More stupidness Mike bad new condenser?

 

Could be, but it should still throw some kind of spark even with the condenser completely removed.

[WHX?? 46,736]

Very correct Mike just for grins try a different coil and let us know. Like I said look for something really stupid. BTW my 753 acts like this every once in awhile but then cures itself? ??

Edited September 25, 2018 by WHX20

[buckrancher 2,675]

that is the original amp meter

I know you said that you have 12 volts at the coil you can manually with your fingers snap open and close the points and see if you have spark with the plug out sitting on a good ground

and do you have the coil wires on right pos. on pos. and points and condenser on neg

 

Brian

[Mike'sHorseBarn 2,650]

46 minutes ago, buckrancher said:

that is the original amp meter

I know you said that you have 12 volts at the coil you can manually with your fingers snap open and close the points and see if you have spark with the plug out sitting on a good ground

and do you have the coil wires on right pos. on pos. and points and condenser on neg

 

Brian

 

I've got it wired up right. I think I triple checked that lol good to know that's the original amp meter, bit I think I trashed the backside getting it out. It was very rusty and corroded. I'll try your trick opening the points with my finger and watching for spark.

[squonk 38,911]

You have to interrupt the flow of electricity flowing thru the primary winding of the coil to ground to make the magnetic field  collapse in the coil to fire the secondary coil to create high voltage to spark the plug. See if you have 12V to the points. I have seen that little wire from the coil to the points crack in side the wire insulation. If you do, then check for 12V at the coil with your tester ground connection at your points to make sure your points are indeed grounded. If your still good, opening the points should create a spark.

Edited September 25, 2018 by squonk

[Mike'sHorseBarn 2,650]

Well guys another evening of work and no spark. My points are sparking though. I turned the key and opened the points and they spark. I cleaned them really good too. It has to be the coil, I'm not sure what else it could be.

[953 nut 51,650]

Mike, when you operated the points and saw a spark did you also put a plug in the plug wire to see if it was sparking?

[Mike'sHorseBarn 2,650]

Just now, 953 nut said:

Mike, when you operated the points and saw a spark did you also put a plug in the plug wire to see if it was sparking?

 

Yes and it was not.

[953 nut 51,650]

Guess that means a bad plug, coil or plug wire. My guess is you already swapped out the plug and plug wire with known good ones.

[Mike'sHorseBarn 2,650]

Yea, I made a new plug wire, it needed one anyway, and a new plug.

[WHX?? 46,736]

And no luck Mike?

[Mike'sHorseBarn 2,650]

9 minutes ago, WHX20 said:

And no luck Mike?

 

Nope, trying a different coil tomorrow evening. If that doesn't do it, I'm fresh out of things to try lol

[Mike'sHorseBarn 2,650]

753 is up and running again! Ended up being the coil. Weird how it just randomly went out while sitting. Thanks for all the help! Now moving on to the 857 whose fuel pump decided to quit working lol