OMC condensers. What is the micro farad and working voltage?

[billy-j]

When going over some of the OMC outboards I pick up, some have had replacement ignition coils already installed in them and the later condensers with the black rubber boot where the lead comes out of them. I realize there is no way to tell the age of the components, but would anyone know what micro farad and the working voltage of new OMC condensers and also a good way to test the existing condensers to see if they are usable? Or would it be advisable to just put in new condensers. Thank You Bill,

[crosbyman]

2nd try  reply went poof ???

 

.22uf is  estimated to be the best all around value  on late 40s to more “modern” magneto/points  well into the 70s until they switched to CDI

Magazine Articles | Western Reserve Chapter

 

see all related  articles on condensers how they work  how to rebuild them

especially parts 1-4  !

Joining AOMCI has priviledges 🙂

[wedgie]

These seem to be working in my test barrel runs. A cheaper alternative to oem.

https://www.amazon.ca/dp/B07N1FJCF3?ref_=ppx_hzod_title_dt_b_fed_asin_title_0_0

[outbdnut2]

Capacitor Voltage rating is only a minimum number the part can tolerate.  You can use a capacitor rated anywhere at or above that number.  I don’t know the minimum for these magneto ignitions, but I think any capacitor rated at  600 Volts or higher would be OK for the maximum voltage spikes encountered at the primary side of the coil.  Crosbyman’s recommendation of .22 uFd  is good.

 

It’s a good idea when substituting capacitors that can’t be clamped or screwed down  to attach them to the mag plate with silicone cement so they don’t vibrate until their lead wires break off.

Dave

[crosbyman]

Well I claim no fame. M.Mohat  tested a bunch and  .22uf  was his conclusion (  see his testing & chart )   . As to the brown caps  I ordered a bunch of them few years ago  and you confirm they work likeI suspected being  600V + and sturdy.  Going on memory …. I am pretty certain properly insulated the will fit inside old emptied out  cap cans  for solid  mounting. Just drill a small hole on the bottom and weld one wire to the can for grounding. the other end  can be  extended a bit and  insulated from the can  and   connected to the points . A  dab of epoxy  or  “corona” silicon in the can  will hold them in place. 🙂

 

m.Mohat  preferred the ceramic stuff $$$ at 850V    but they are very tiny to work with and solder. I got some cheap ones from amazon but never got around to installing them in a cap. can.

Joining AOMCI has priviledges 🙂

[Tubs]

 

I got this inexpensive mutli-meter at Harbor Freight that can tell you the value of your condensers. The reading is in nano farads though. As far as if they’re still good, you need a taster like a Merc O Tronic. How bad do you want to know? I have one and could test them for you if you wanted to send them to me.

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

[crosbyman]

if you are into oldies much or will be  after you are infected with the hobby… you can build your own load tester for caps.  See Mr Mohat’s PART 2  article

I built his  basic model   and it has an idiot lamp for GOOD -NOT GOOD   during a load tests  at about  250V+

 

 

Joining AOMCI has priviledges 🙂

[crosbyman]

see all you need  on condensers on the wester region aomci site where m.Mohat explains it all

Magazine Articles | Western Reserve Chapter

https://wrcoutboards.org/wp-content/uploads/2020/04/Part1_Condenser_Construction_Failure_Modes.pdf

https://wrcoutboards.org/wp-content/uploads/2020/04/Part2_Condenser_Testers_And_Testing_Correctly.pdf

https://wrcoutboards.org/wp-content/uploads/2020/04/Part3_Sizing_Condensers_Correctly.pdf

https://wrcoutboards.org/wp-content/uploads/2020/04/Part4_Repairing_Broken_Condensers.pdf

https://wrcoutboards.org/wp-content/uploads/2020/03/Articles_Ignition_Part3_Magic_Of_Magneto_r.pdf

 

Joining AOMCI has priviledges 🙂

[outbdnut2]

The tester Tubs showed is good for measuring capacitance (uFd),  and if that is right, chances are good it will work, but it does not put a big voltage on them looking for leakage or breakdown. There aren’t many options for testing that do that.  I use an old Heathkit capacitor checker that can put up to 600 volts on them.  Works great!, but Heathkit is long gone and when they show up for sale, they aren’t cheap!  With electronics being a hobby of mine as a kid that developed into a lifelong career, I bought mine new in the early 1960s and put the kit together.  It is an electronics lab instrument.   There are some on E-Bay right now, but I was really surprised at the prices.  The kit I bought in the 1960s cost me $29. Link and photo below.  I have a model IT-11 which is same as the IT-28 except for color.

https://www.ebay.com/sch/i.html?_nkw=Heathkit+capacitor+tester+checker&_sacat=0&_from=R40&_trksid=p4432023.m570.l1313

Dave

[Author]

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