What is this white wire?

Sun Aug 10, 2014 8:28 am

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This A has been a labor of love. I've been piecing this thing back together slowly over the months and need to figure out what's next to get it back to life. From this white wire to the regulator wires on the opposite side... it all needs replaced. I just need to figure out what goes where.

I spent HOURS trying to rebuild the starter and finally had to enlist professional help. I just got it back and am itching to get the engine to run.

Re: What is this white wire?

Sun Aug 10, 2014 9:02 am

That would be the kill switch wire. You should have a switch on the tractor to attach this wire to. You can run the tractor without this connected, but you will have to ground this wire out to kill the engine.

Re: What is this white wire?

Sun Aug 10, 2014 9:02 am

The white wire is the kill wire for the magneto. Originally it went to a single terminal switch on the dash that grounded it to shut off the spark. The way it is at present, someone has just been touching it to the metal case of the magneto to kill the engine. be sure to use an insulated screw driver or only hold the insulation to do this though, it WILL BITE.

Re: What is this white wire?

Sun Aug 10, 2014 9:13 am

I see your A has the tall oil filter on it. It must be an early one!

Al

Re: What is this white wire?

Sun Aug 10, 2014 9:46 am

Wow the immediate responses are refreshing! Thanks for all of the input! I believe from running the serial number it is a 1941. What does this engine need to minimally run? Im wondering if I can get by today without rewiring everything to include the regulator. The starter is fast and strong when being powered by a 12v battery but it just cranks and cranks and cranks without even one sign of life. Ive replaced the spark plug wires (in correct order) since the cows ate through the originals. Ive also replaced the spark plugs just for good measure. In thinking everything else is mechanically/electrically sound, Im stumped as to what could be hanging this ol' girl up. The original owner died several years ago but the widow and son have made it clear that it was parked in running order. I've been feeding the carb small doses of ether in hopes of hearing it want to jump to life.

Re: What is this white wire?

Sun Aug 10, 2014 10:09 am

It will run without any of the wires you mentioned being connected. Be sure that nothing is connected to the F terminal of the generator. Did you use solid copper wires for the spark plugs? Make sure the short wire on the magneto isn't touching anything. Have you checked for spark at the spark plugs?

If it was indeed running when parked, there are only a few things that could be keeping it from running. If you don't have a good blue spark at the plugs, work on the ignition. If you do, start checking the fuel system and carburetor. If you haven't done anything to the carb, it probably could use opening up and cleaning. Make sure you have good fuel flow etc. I'm not going to go into details on working each of those systems over as a little detective work on your part can get things focused onto one area or another.

Most of the general comments that can be found on this site about getting a Cub to run will equally apply to an A.

Re: What is this white wire?

Sun Aug 10, 2014 12:20 pm

I will go out on a limb and say tile the points or replace them and you should get it to fire

Re: What is this white wire?

Sun Aug 10, 2014 2:57 pm

Boss Hog wrote:I will go out on a limb and say tile the points or replace them and you should get it to fire
may be able to use use a fine file on them to clean the contacts for the time being, but if it has been setting a long time it may need a coil also.

Re: What is this white wire?

Sun Aug 10, 2014 6:58 pm

Jim Becker wrote:It will run without any of the wires you mentioned being connected. Be sure that nothing is connected to the F terminal of the generor. Did you use solid copper wires for the spark plugs? Make sure the short wire on the magneto isn't touching anything. Have you checked for spark at the spark plugs?

If it was indeed running when parked, there are only a few things that could be keeping it from running. If you don't have a good blue spark at the plugs, work on the ignition. If you do, start checking the fuel system and carburetor. If you haven't done anything to the carb, it probably could use opening up and cleaning. Make sure you have good fuel flow etc. I'm not going to go into details on working each of those systems over as a little detective work on your part can get things focused onto one area or another.

Most of the general comments that can be found on this site about getting a Cub to run will equally apply to an A.


Thanks Jim! I purchased the generic replacement spark plugs and wires at Tractor Supply. Not sure what they consist of. The spark plugs are Autolite. Nothing is hooked to the generator at all thanks to the cows. That white wire wasnt touching anything when trying to start. I pulled the spark plugs again and turned the engine with the starter while the spark plugs were resting on the block. Every one had a nice blue spark. Im not sure how strong the sparks were but am wondering if replacing the coil is in need anyway since it definitely looks original.

I will be opening up the carb.

Re: What is this white wire?

Sun Aug 10, 2014 6:59 pm

Boss Hog wrote:I will go out on a limb and say tile the points or replace them and you should get it to fire


I took a file and lightly brushed up all points of contact.

Re: What is this white wire?

Sun Aug 10, 2014 7:01 pm

John *.?-!.* cub owner wrote:
Boss Hog wrote:I will go out on a limb and say tile the points or replace them and you should get it to fire
may be able to use use a fine file on them to clean the contacts for the time being, but if it has been setting a long time it may need a coil also.


Ah I forgot to include this post. I did file down the contacts and am considering a coil but am not sure if I necessarily need one or not since I did have blue sparks when tested.

Re: What is this white wire?

Sun Aug 10, 2014 7:08 pm

So in squirting some ether into each cylinder, replacing spark plugs, I received a HUGE backfire. I ended up trying time and time again to get the ol' girl to fire off but it never happened. I ended up running my 12v battery near flat. I didnt want to give up and hand cranked for awhile. I received another backfire and some smoke but nothing. I havent done anything to mess with timing. Random backfires would indicate a timing issue to me but they were few and FAR between. Scratching my head.

Re: What is this white wire?

Sun Aug 10, 2014 8:22 pm

More shots of the electrical nightmare:


Imageurl=http://s1296.photobucket.com/user/AgTires4295/media/Mobile%20Uploads/20140711_132234_zps012dc1ac.jpg.html]Image[/url]url=http://s1296.photobucket.com/user/AgTires4295/media/Mobile%20Uploads/20140711_132252_zps2a2fd593.jpg.html]Image[/url]

Re: What is this white wire?

Sun Aug 10, 2014 9:00 pm

When you turn it with the crank do you have good compression on all cylinders? an intake valve sticking open will cause the backfiring.

Looking at the picture you appear to have the number one spark plug wire in the right place but can't tell about the others. Going clockwise around the cap, the next should be 3, then 4, and lastly, 2.

Re: What is this white wire?

Mon Aug 11, 2014 8:07 am

John *.?-!.* cub owner wrote:When you turn it with the crank do you have good compression on all cylinders? an intake valve sticking open will cause the backfiring.

Looking at the picture you appear to have the number one spark plug wire in the right place but can't tell about the others. Going around the cap, the next should be 3, then 4, and lastly, 2.


Yessir that's the order I have them in. When turning the crank, it feels like equal resistance across the board. In listening to the starter, if I had a sticking valve, would it sound like there's a skip or a rotation where it spun a heartbeat faster? This is not the case, but am making sure I am tracking with you.