Bad coil
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- This topic has 12 replies, 4 voices, and was last updated 3 years, 9 months ago by jcrigan.
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June 16, 2020 at 6:46 pm #205935
If I have a single cylinder antique outboard, with a bad coil, can I run the engine with a buzz coil? What about a twin cylinder , could you do the same?
It's a jungle out there.
June 16, 2020 at 7:16 pm #205937Assuming you are talking about a Model T coil… if the points close at the time of firing, you can use a buzz coil for each cylinder. This is how I run my early Evinrude. You can’t fire more than one spark plug at a time unless you open up the coil and separate the secondary from the primary. (The contact on the bottom of a Model T coil is common to both windings).
If the points open at the time of firing, it can be done but you need a relay for each coil so that the coil fires when the points open. The problem with this arrangement is that there is a lag, so you can’t do this with something that turns really fast. I’ve done this with a Caille RBM, and if you search this site you’ll find the wiring diagram.
If you need to run an opposed twin on a buzz coil, you can set up a set of Model T points at the end of a Zephyr coil. This is how my battery / coil box is set up. To run a single cylinder motor, I ground one side of the secondary leads to the same lead that attaches to the engine, not the one that goes to the isolated point. To run something like a Koban, I can run separate leads to each cylinder instead of grounding one.
If you have a motor with rare, bad coils and the primary is good, you can strip off the secondary and mount an OMC coil anywhere on the motor. Hook the primary wires from the OMC coil to the primary leads of the one in the mag plate, then a high tension wire from the OMC coil to the spark plug. It’s not pretty, but I ran a little Mercury like this quite a while ago.
T
June 16, 2020 at 7:30 pm #205938Thanks for the reply tom youve helped me a couple of times in the past. I’ve got a few old motors (late twenties fleetwin and an old 36 or 38 champion single that are getting no fire after cleaning everything I know to clean. Electricity is NOT a strong point of mine and this coil thing is giving me fits. Primary secondary ….. It’s all Greek to me. If you know of any good sites to school myself id be grateful
It's a jungle out there.
June 17, 2020 at 5:09 pm #205997On the 38 champion if I unhook the points and condenser and set the flywheel on and spin it with my hand while holding the plugwire I get fire but with the points and condenser hooked up nothing, does this make sense?
It's a jungle out there.
June 17, 2020 at 7:30 pm #206009You may get “fire” but I doubt it’s enough to fire a spark plug under compression. Does this motor have a WICO mag? If so, I’d suspect a bad condenser. T
June 18, 2020 at 10:29 am #206070I’ve heard of wico but don’t know how to identify one. Still kinda new to this, learning a lot along the way thanks to the club. When I get home this evening I can take a pic. And your probably right about the amount of fire, as it was just a tickle to my finger. Just thought it strange I got nothing with points hooked up.
It's a jungle out there.
June 18, 2020 at 11:08 am #206076- This reply was modified 3 years, 9 months ago by The Boat House.
- This reply was modified 3 years, 9 months ago by The Boat House.
June 18, 2020 at 8:03 pm #206104That old condenser may be bad. Go to your auto parts dealer and get one for a 1962 chevy nova six cylinder. They are a 0.02 uf capacitor. And they are cheaper in cost than most.
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