H4 magneto condensor to short to reach grounding screw

slydog

Member

I bought a points and condensor for an H4 magneto and the condensor is shorter than my old one and won't reach the grounding screw. What do I do now?
Also is there a way to test my old condensor? Maybe it is ok and I can just use that and my problem will be solved.
 
Condensers almost never go bad but new ones are now likely to be bad from the get go. I have not change a condenser in well over 10 years now
 
You ask " What do I do now?" A properly done short splice would work.

"Also is there a way to test my old condenser" YES a true full fledged capacitor tester will work and if you're good with an old style analog ohm meter a "kickback" test can provide some degree (although not perfect or complete) of evidence of its condition. Basically if its always a total dead short its bad or if its completely open (IE no capacitor action whatsoever) its bad. Once charged a good condenser is an open circuit to further DC current flow, but when discharged it will initially accept current flow.

There's a good chance an old condensor may be better then a new out of the box unit, give it a try. With no condenser in the circuit at all it can still fire albeit weaker plus the points will burn prematurely, but if its a dead short you get no fire at all.

Try the old one n see what happens.

John T
 
I robbed a condensor from another mag I had and it seems to work although I have spark it is pretty weak. I am thinking my next step is going to be replace the coil. FYI this mag is the one that would work great when the engine was cold but when it warmed up it would start to miss and sometimes even quit and the motor would stop. Then I couldn't get it started until the engine cooled down and then it would start right up. Would the coil be the cause of something like this?
 
(quoted from post at 17:50:53 02/04/18) I am thinking my next step is going to be replace the coil. FYI this mag is the one that would work great when the engine was cold but when it warmed up it would start to miss and sometimes even quit and the motor would stop. Would the coil be the cause of something like this?

A "thermally-intermittant" coil certain can cause the issue you are having.

Just a warning, if you decide to replace the coil, don't get rough with the coil, trying to get it out of the old coil core. While the core LOOKS solid, it's actually laminated and easily damaged. Better to carefully cut the old coil off than to destroy the core.

Post back if you have questions, I have photos of a coil core that didn't survive, photobucket is holding them hostage, but I can find them on my 'puter and re-upload.
 
When the engine is running the coil does start to warm up and if it has a bad spot in the coils wires it will do just as your is doing so simple answer is yes your coil may well be getting bad
 
Ignition problems that happen ONLY after she gets good n warm can possibly be coil or condenser related. Again if theres no condenser at all in the circuit or its weak she can still spark although its weaker and the points will burn sooner.

Another problem can be points that are burned pitted and/or carboned, you might check that.

Since a condensor is so much cheaper then a coil Id try that before a new coil.

John T
 
How do you suggest I get the coil center out? Can I tap on it with a hammer
and see if it will slide out? You say they are laminated? I have never had
one out so not sure what it looks like.
 
As I wrote previously, if the coil can't be pushed of the core easily but hand, it's better to carefully cut away the coil than to wreck the core.

You don't want to destroy the core, last CIH list on D21314 core was $587.82!!!!

<img src = "https://i.imgur.com/etRLG9k.jpg">

Here's what happens if you get rough with the core!
 

I'm not really new here but have not been on forum in long time.

I have a Farmal BN that runs a woods L306 mower and has been a good machine for about 3 decades! Then yesterday it developed a problem where just flat out quit. At first thought I had run out of gas but that was not the problem.

Sometimes it will fire right back up and run good then other times it just cranks and no start.

I checked for spark at the wire that goes from coil cover to the distributor cap on the mag and it seems very weak and hard to see in daylight more of a yellow spark not the blue spark I was hoping for.

One more thing while I was checking for spark when it seemed to be running pretty good after mowing for about half an hour and it had started good just before checking spark I reconnected the wire to the distributor cap and now it would not start. I'm thinking it might be getting hot from the heat of the engine.

I do have the original condenser and coil that were in the magneto when I first got the tractor probably over 30 years ago so maybe I should try changing one at a time?
 

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