123 Help

[Sean Sokoly]

Inherited my late fathers 123, which he became second owner of in 1974. She had a been sitting a few years after we bought a snowblower. Got it running last November, had a head gasket blow upon start up, battled a bad ignition switch both have been replaced. Had it running so so, could never get the aftermarket carbs to adjust right, gas pours out of them. My problem now is back to where I was last year when I first attempted to get it running. I get 12v to the coil nothing on - on coil till I rotate and get the points opened, I then have spark and the test light comes on. I get spark when I turn the key off when the points are not opened, Engine wont even crank, brand new battery. I get nothing on the test light when its in the coil secondary. I'm thinking bad coil or bad condensor.

 

[kmcconaughey]

Sean, WELCOME! Lets start with the schematic. Note that there's a safety switch in the schematic. If the engine won't crank over, it's possible that the safety switch is not being depressed. I can see in your video that you have the brake pedal locked down.

If you look under the tractor you should see on the brake pedal shaft a spring clip that presses on the safety switch. It might be possible with the lift handle pulled back to be able to look down through the slot in the frame where the lift handle is on the right side of the tractor frame. Here's a photo taken looking through that slot at the spring clip. Note this is a parts tractor and the lift handle has been removed so it won't be quite this visible on your tractor.

 

[Sean Sokoly]

Ah ha, found this on the floor the other day under the tractor all of a sudden!
https://photos.app.goo.gl/tb9zxtengLAMJcYe8

 

[mfrade]

Sean, when you shut of the ignition switch -the coil should fire off. Anytime you break the flow of electricity to the coil, the primary field collapses into the secondary creating the high voltage needed for spark. I'll say the coil is fine. If you find the safety switch isn't functioning, you can bypass it with a short wire or paperclip or cotter pin.. anything to complete the circuit for testing. See if it'll crank. I would remove the points and condenser, for cleaning and inspection. Test the condenser for continuity, mounting tab to the wire connector, it should read a small value of ohms. it should not read open and it should not read infinity (closed circuit). Clean the faces of the contact points with a points file or very fine sand paper or crocus cloth, anything to break the tarnish that develops and then test the points for a short across the pivot. You can easily do that by putting a piece of paper or cloth / rubber in front of the points where they contact. Then see if you get any continuity across the mounting surface and the contact faces. You shouldn't.
Report back after testing.

 

[mfrade]

Ah ha, found this on the floor the other day under the tractor all of a sudden!
https://photos.app.goo.gl/tb9zxtengLAMJcYe8

Looks like you found 1 culprit!

 

[kmcconaughey]

Yep, they get weak around that hole that keeps them aligned and eventually they break. Time for a new spring clip. Until then you can jumper the switch with a wire and get back to testing.

 

[fcurrier]

Welcome, Sean. Hoping you get familiar with the history of the 123 - "The Tractor That Introduced the Hydrostatic Transmission to Cub Cadet".

 

[Ron Armbruster]

Welcome to the best Cub Cadet forum. Tons of information and great folks willing to help.

 

[Sean Sokoly]

Ok, thanks for the advice so far. Best way to bypass safety switch? I pushed the button in on switch with the brake pedal down, no change. Thinking the switch may be toast also. I see Orange/Black on the Solenoid and solid orange out of the harness to keyswitch.

 

[dschwandt]

Pull the wires off the switch and put a short jumper in them.
I'd remove the switch, clean it up and get it WD 40'd, work in in and out and it just might come back to life for Ya.

 

[raporter]

Sean, All the advice you are getting here is great ! I would only add,,, Check The ground connections. a loose or dirty connection, specially the cable that connects to the engine block, can drive you bonkers ! I have solved several issues that way. Not sure that will solve anything,, but can't hurt. Enjoy your Cub !

 

[Sean Sokoly]

Thanks for all the help. Definitely got some things to do later today/tonight!

 

[Sean Sokoly]

I'm guessing this is the clip I need after verifying the safety switch is ok: Cub Cadet IH-394037-R1 MTD Safety Switch Release Clip 105 107 123 125 127 | eBay

 

[kmcconaughey]

Yep, that's the part but it's about $10 too expensive. CC Specialties has them for a tad over $8. Click the link below and scroll way down near the bottom of the page:

CC Specialties

 

[Sean Sokoly]

Yes, the bracket is the culprit! The switch tests ok with a meter. I got it to fire up, ran and then quit. Gas is dripping from the carburetor, been an issue before this. Stuck float maybe? I also set the points to .020 as well. Attached are videos of where I'm at now.

 

[fcurrier]

Good battery! How's that head gasket?

 

[dschwandt]

That thing should NOT start that hard.
Static time it!!
Should have been running about the 2nd time it turns over

 

[Sean Sokoly]

Good battery! How's that head gasket?

Replaced last November.

 

[eweiss]

Sound's like a compression issue, Head gasket and / or valve problem

 

[kphill]

I would remove the spark plug and check it.. Is it wet with fuel?.. Also check it with an ohmmeter.. put one probe on the electrode post and the other end on the threaded part and see if you are getting a reading.. If you are the plug is grounding out and you are not getting a spark.. I noticed it was putting out a puff of unburned fuel from the exaust and that indicates no spark or dead gas..