C160 auto electrical

[chorusguy 227]

Hi all.  I'm very ignorant about electrical issues, so I need kindergarten level explanations here.

I rewired my c160 auto.  Replaced coil, regulator, and points.  Moved switch and spark plug over from a machine that was running until it threw a rod.

 

It turns over, but am getting no spark.  There is 12 volt to the points in run position.  Can anyone help me from here?  It had a very weak spark before I put on new components for a couple of attempts, then nothing.  Have cleaned the area behind the points on the block and seem to have a good ground there.

 

Thanks in advance

 

Robert

[ebinmaine 67,647]

A few things pop into my head...

 

Did you remove and reinstall the used parts from machines that were exactly alike?

In other words, they were both points and battery type ignitions. One was NOT a Tecumseh engine or a Kohler with a magneto?

 

Do you have a copy of the diagram that you used to wire your tractor?

 

Does the wire at the back of the ignition switch that goes to the I terminal, connect to the positive side of the coil? The points and condenser should both be on the negative side of the coil.

 

Have you started at the ignition switch on the I terminal, verify the exact position that goes to. Say it's another switch or safety? Are you getting voltage down to that, and then back out of it? Keep following the stream?

 

 

[chorusguy 227]

Yes to machines.  Both c160 autos with 16hp kohler.  One minor difference is the machine im working on has what appears to be an in line fuse, but power is passing through that.

 

Downloaded a wiring diagram from another post. It compares to another I also found on line.

 

Both points and condenser are on negative side of the coil.  I havent traced voltage from I tab yet, that's my next step

 

Thanks so much for your reply

[ebinmaine 67,647]

1 minute ago, chorusguy said:

traced voltage from I tab

 

 

Figure out where the ends of that wire are and check it with the tractor off so you can see if it has continuity.  

 

Keep asking questions. We'll get this thing up and running for you.

 

 

[chorusguy 227]

Ok. Thanks. I'll do that next

[gwest_ca-(File Mod) 11,048]

If you have 12 volts at the points that is normal when the points are open.

 

You should have 0 volts at the points when the points are closed.

If not 0 volts the point contacts need to be cleaned. That contact is what takes the voltage to 0 volts.

[chorusguy 227]

Gwest

Is that with the negative probe on the screw where the wire connects to the points?

[gwest_ca-(File Mod) 11,048]

Negative probe goes the the engine block or a good battery ground.

Positive probe to the coil (-) which is easier than doing it at the points. The points and condenser are connected to the coil (-)

[chorusguy 227]

Ok. So, here's what I have.

 

I grounded my meter, put positive probe on screw that connects the wire to the points.  With points closed, it reads 12 v.  When I turn it over, the volts drop to about 9.5 as the starter is spinning.  In run position if I probe the points, I get a spark from the probe to the points.  Although, I dont think it matters, I have nothing plugged into the accessories tab on the ignition switch. 

 

My switch isn't labeled, but has the two rows of 2 and a row of one.  Ignition wire is plugged into second row left.  Am using this schematic as my reference

[chorusguy 227]

All tabs show 12 volts in run position except red tab (start) but it shows 9.5 volts when I turn the key

[chorusguy 227]

I get 12 volts in run at the body of the points, so I think they are grounded ok

[gwest_ca-(File Mod) 11,048]

Take the spark plug out so you can turn the engine over by hand clockwise looking at the flywheel.

When the points are open you should have 12 volts at the coil negative terminal.

When the points are closed you should have 0 volts at the coil negative terminal.

This will cycle one time for every two turns of the flywheel.

 

 With points closed, it reads 12 v. 

You need to clean the point contacts because with the points closed that wire should be grounded which will give 0 volts.

You can use a nail file to polish the contact surfaces. I usually use a strip of clean white paper and drag that through the closed contacts until the paper comes out clean.

The oil applied to new points by manufacturers is enough to prevent an electrical connection when the points close. They need to be clean.

 

[chorusguy 227]

Gwest.  Thanks.  I will try again.  I have pulled a mineral spirits dampened card stock through the points, but will try again.  Perhaps some 1000 grit sandpaper?

[squonk 41,158]

Points are basically an on off switch. You need that voltage to change from 12 to 0 when cranking. The 12volts that travel from the switch thru the coil to the points to ground needs to be interrupted (points open) to collapse a magnetic field in the coil to get high voltage out of the coil to create the spark at the plug. You can have a million volts on the coil primary wiring. But if it doesn't stop flowing , nothing will come out of the spark plug cable.

 

https://krankengineering.com/points-ignition/#:~:text=The current flowing through the,as the points gap opens.

Edited May 10, 2023 by squonk

[chorusguy 227]

Thanks. Squonk. That makes sense.  I never knew how that all worked.  Great info.  I really appreciate your help

 

 

Robert

Edited May 10, 2023 by chorusguy
Misspelling

[clueless 3,005]

In your first post you said you replaced the coil, the regulator and the points, did you replace the condenser?

[chorusguy 227]

Clueless, I did replace the condenser

[953 nut 55,324]

From the story you are telling us it sounds like your points are never closing. With the points cover removed, sparkplug removed and the key off rotate the engine and observe the points. The points should be closed completely the majority of the time. when the points are opened to their maximum opening there should be a gap of 0.020".

[chorusguy 227]

I see the points closing, but it is possible that the gap is wrong.  Picking up feeler guages tomorrow.

 

Thank you

[oliver2-44 9,761]

@953 nut Could you post your write up on how to do static timing. It might help him. 

[squonk 41,158]

[chorusguy 227]

Thanks.  953nut suggested that perhaps the points weren't closing, so I will loosen the set screw and let them close all the way down and then check for voltage of zero with the key on. That should let me know that the points are clean and conducting electricity.  Then I'll reset the gap and see what happens.  

 

I really appreciate all the help you are giving me.  

 

Thank you, 

 

Robert

[953 nut 55,324]

8 hours ago, oliver2-44 said:

@953 nut Could you post your write up on how to do static timing. It might help him. 

These vidios do a better job of showing how to adjust points than I can. The Kohler manual tha Mike @squonk posted is a good reminder if you already know how to do Static Timing.

Here are a couple of good videos from I Save Tractors. The first one shows how to set points with a 0.020" feeler gauge and the second is Static Timing. I prefer to use a 12 volt test light rather than a meter for static timing because the light will get your attention better than a meter. Attach one end of the light to the battery positive and the other to the points lead. The sight hole in the flywheel cover is shown in the first picture.

 

 

[chorusguy 227]

Thanks!

 

Robert

[chorusguy 227]

Hi all.  It's been awhile, but thought I'd tell you what is going on.  I re-cleaned the points and gapped them.  I was totally doing that wrong. Cleaned the spark plug and, lo and behold, I got a spark.  Replaced the spark plug with a new one and repaired the spark plug hole.  (I had stripped it out.  I actually, didn't do that repair that well.  The hole is slightly tilted.) Put a little gas in her, shot some carb cleaner in the carb and after a few whirls, she started up.. I am so happy.  THANK YOU, THANK YOU, THANK YOU for all your help.  Next step is swapping out the steering column, putting the seat back on and fixing or repairing the choke cable.