Correct mfd Condenser

[ScottNC]

This goes back to the mid 70's and using a Sun 1120. I recall something about depending on which way the ignition point contacts are transferring material you can determine if the condensers microfarad value matches the application.

My front mount distributor 2N's ground side contact pits while the coil side (arm) has a peak to match the pit. The tractor is 12 volts, the coil is an externally mounted NAPA can that's internally resisted. Starting with freshened points gaped to .015" the engine runs fine for about 10 +/- hours of use. Then it begins acting up and eventually won't start, requiring another touch-up of the points with a diamond lap and re-gaping.

I'm wondering if by selecting a condenser of different mfd the pitting can be reduced or eliminated and the time interval between maintenance extended?

 

[Steve@Advance]

I recall something about that, barely...

But where would you find condensers with the mfd listed, or given a choice? You're doing good to just find one that works!

Since it is no longer stock, I would look into converting it to electronic considering the difficulty of having to remove the distributor every time to deal with it!

Might also verify that it does have a true 12v no resistor needed coil. It could be the wrong coil, or defective and drawing too many amps. If it gets hot when in use something is not right. It should be about the same as the surrounding components and not too hot to hold your hand on.

Aftermarket coils are dinosaurs, they no longer have the quality the old ones had, and are often misboxed. Having the correct coil is essential even with electronic conversion.

 

[wore out]

(quoted from post at 06:12:56 07/22/22) This goes back to the mid 70's and using a Sun 1120. I recall something about depending on which way the ignition point contacts are transferring material you can determine if the condensers microfarad value matches the application.

My front mount distributor 2N's ground side contact pits while the coil side (arm) has a peak to match the pit. The tractor is 12 volts, the coil is an externally mounted NAPA can that's internally resisted. Starting with freshened points gaped to .015" the engine runs fine for about 10 +/- hours of use. Then it begins acting up and eventually won't start, requiring another touch-up of the points with a diamond lap and re-gaping.

I'm wondering if by selecting a condenser of different mfd the pitting can be reduced or eliminated and the time interval between maintenance extended?

The drawing shows a (+) ground system (as yours should be).

For (-) ground systems metal transfer would be opposite.

The old rule is: ''If there is ''minus'' material (pitting) on the ''minus'' (negative) side of the points, then you have ''minus'' (not enough) capacitance.

Looks like a condenser of slightly less capacity (mfd value) might be beneficial in your case.

 

[John T]

Heres the illustration I have that may help. The condensor rating is tuned to the coils inductance for best
results and point life. Take into account if youre at POS or NEG Ground of course.

John T

 

[ScottNC]

Perfect, thanks guys!

 

[mEl]

It would be helpful to know the primary resistance of the coil. I have been having trouble with defective condensers for several years from the most popular aftermarket tune up kits available at most farm equipment stores and online parts sites.

My recommendation would be to go to Napa or your favorite auto parts and get Standard or Echlin or name brand stuff.

If your primary ohms are in the 3.5 - 4 Ohms area you should not be having points burning issues.

You would have to get with someone a lot smarter than most parts guys at the auto parts to start comparing condensers by Microfarads rating to swap to try to correct your problem. I have seen systems run for years with points with peaks and valleys.