What are points?

[urmominabox42 2]

Hello, i'm new to the community and was informed my new (to me) 417A requires new "points" among other things.  This terminology confuses me as i'm slightly dumb in the tractor/small engine community.  Can anyone help explain to me what "points" are?

 

Thank you for your time!

[squonk 43,799]

Points are the trigger for your ignition system. You have a coil with a primary circuit and winding. Current flows thru this circuit thru the points to ground completing the circuit. When the points open the current stops. This causes a magnetic field in the coil to collapse inducing a high voltage surge into your coils secondary winding thru your spark plug wire and then it sparks across the gap in your spark plug. This fires you engine. The points run off a push rod on your camshaft and need to be gapped to open at the correct time.

 

 

 

 

 

 

 

Edited April 21, 2021 by squonk

[squonk 43,799]

That video is for a car system. So eliminate the distributor but the function is the same.

[953 nut 59,924]

With a battery ignition system, the ignition points are closed the majority of the time. With the points closed and the ignition switch ON the primary windings of the ignition coil have current flowing through them and are developing a magnetic field in the iron core of the ignition coil. The moment the ignition points open the magnetic field collapses and induces a momentary high voltage pulse in the secondary windings of the coil which goes through the spark plug wire and arcs across the gap of the spark plug. If this occurs in the presence of a compressed fuel/air mixture of the proper ratio an explosion will occur within the cylinder. If this explosion occurs at the proper time in the engine’s cycle there will be pressure applied to the piston forcing it downward on the power stroke. The ignition points will continue to open further after this has occurred. How far they open is immaterial, their work has been done for that cycle of engine operation. What is important is when they open relative to the position of the piston on its compression/power revolution. If it occurs too soon there will be backfiring, too late and there will be a reduction of power. In the case of our Kohler engines the sweet spot is twenty degrees Before Top Dead Center, that is what the “SP” mark on the flywheel is set to). At the moment the points open the condenser quenches the arc across the points extending their life, the rest of the time it just sits there.

Your ignition points are located on the top of the engine. The manual below should be helpful.

Gapping the ignition points at .020 has always been the standard answer to how points should be set. That probably will get you into the ballpark where the engine will run, but with a bit of additional effort you can improve the engine’s power and performance.

The Kohler engine manual in the Red Square files section covers two methods for setting the ignition timing, Static Timing and using a Timing Light.

 

[Handy Don 14,061]

I think what you need to know is:

- the points are a kind of electric switch necessary for the engine to run

- they do require periodic adjustment and/or replacement to work properly

- the part itself is not expensive

- the effort needed to adjust/replace them varies depending on the kind of engine you have

 

The related part that also requires periodic replacement is the condenser, also necessary for the engine to run.

Edited April 21, 2021 by Handy Don

[The Tuul Crib 7,339]

T😎

[oliver2-44 10,711]

 Lots of friendly helpful advice here.

 

 

Edited April 21, 2021 by oliver2-44

[SylvanLakeWH 28,392]

[richmondred01 2,307]

Replace your condenser when replacing the points. 

[Maxwell-8 4,367]

maybe just try and sandpaper the points

Edited April 22, 2021 by Maxwell-8

[Pullstart 66,706]

Welcome to RedSquare!  You’ll notice the people on this forum seem to be a bit more responsive and helpful than so many other forums.  It’s the best place on the web!

 

If you chose to clean your points, a small file or a dollar bill are the best ways to achieve that.  Sandpaper embeds small scratches with debris and will shorten the overall life of the points.  A file or dollar bill will polish the points, which is what you’re looking for.

Edited April 22, 2021 by pullstart

[ranger 1,798]

Hi, and Welcome. 

If at any time you’re looking at electrical circuit diagrams for older vehicles, you may see a component described, C.B. (Contact Breaker), these are the ‘Points’ being discussed here. Another term you will come across is, ‘Dwell Angle’, this refers to the amount of time in degrees the ‘Points’ are closed to enable the coil to ‘Charge’. Points gap will affect this ‘charging / re-charging’ time as well as affecting ignition timing. Too large a gap will advance the timing and reduce the dwell angle, and vise-versa. High speed multi cylinder engines can have issues with insufficient dwell angle, ie- not enough points closed time, but not really a problem with our, relatively slow old plodders!

 

Doug.

Edited April 22, 2021 by ranger

[WHX?? 51,739]

 Sounds like the guys got you covered so 

[urmominabox42 2]

Thank you everyone! i was able to locate and remove the old points and now have a much better knowledge of my motor! you all rock!!

 

 

[richmondred01 2,307]

Great.

Edited April 27, 2021 by richmondred01