what does the condenser do...?

[dfrants]

got a 1973 9.5 Johnson that started missing, pretty much at all speeds. I replaced the points. the coils will be next. what does the condensers do and how do you tell if their bad?

 

[GA_Boater]

The condensers stop arcing of the points and assist in creating a hot spark. Symptom of a bad or going bad one is the motor misses. Usually points and condenser are changed as a set. Hold off on buying coils.

 

[F_R]

Briefly, a condenser stores electricity. When the points open, electricity surges into the condenser (instead of arcing across the points). Then it surges back out through the coil and the spark is created. This is a greatly simplified explanation. There are crude tests you can do with a mulltimeter, an accurate test requires a capacitance tester. Generally speaking, they all leak. It is a matter of how bad they leak. That is why it was customary to just replace them back in the day. Nowadays, people are too cheap to do that, so they just use 'em.

 

[metriccrescentwrench]

..... Usually points and condenser are changed as a set......

Yep, I remember the 'good old days' when working on engines was 'simple'. A condenser always came in the kit with new points, there was a good reason for that.

 

[racerone]

The universal magneto can be repaired by someone with some skill and a WILLINGNESS to learn.-----A $500 CD module on newer motors can only be replaced.-----Some of these 1950's motors will be running long after the new plastic junk has been thrown out.---------On the 9.5 do not forget to inspect the bottom of the coils and the plug wires where they come out of the magplate.

 

[gm280]

Condensers are merely just capacitors. And their function is to absorb the voltage into the condenser instead of arcing across the points and burning them as they open to fire the spark. If the condenser shorts, then there will be no spark at all. And if the condenser opens, the points will burn in short order. But most of the time, they do their job without much concern. Some quality multi-meter will have capacitor testing function on them and condensers can be tested quickly. Personally I haven't seen very many bad condensers... Condensers in a typical point ignition systems are very low on the Farad scale, usually in the .25 microfarad range or there about! JMHO!

 

[racerone]

I see them pass a test on a MERC-O-TRONIC magneto analyzer when at room temperature.------They fail after soaking up some heat !!!!!

 

[gm280]

I see them pass a test on a MERC-O-TRONIC magneto analyzer when at room temperature.------They fail after soaking up some heat !!!!!

racerone, all types of electronic parts can fail with heat applied. Condensers are not unusual to that issue... If you really want to test them statically, use a heat gun when testing and see what passes. Nothing new about heat related problems though for electronic parts. Coils, condensers, stators, exciter coils, even terminal connections have their problems when heat or even very cold temperatures are applied. :noidea: hwell:

 

[racerone]

????--------That is how I test them and have for many years !!!!!!--------I recall towing a boat in from a big , big lake.--------Motor refused to start after it had been shut down to allow a skier to climb aboard.--------Motor started right up at the marina.---------Tested the warmed up condenser and replaced it.----No more restart problems for the folks.