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Let me clarify. This does go to the points also. It is used to make the the magneto discharge so that you get spark. So it DOES need to connect to the points. Usually there is aware that goes on back to the console to maybe key switch that has only one wire and when the key switch is turned it grounds that wire solid. Therefore the magneto can never fire.

Hope that clarifies things.
 

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QUOTE: That terminal has a wire on the outside that then went to two things....one was the points/condenser, but the other wire went to a ring terminal that was attached to a small square of steel and was attached under one of the points cover can screws. Effectively ground it.

I think the ring terminal that went 'under the points cover screw' was likely insulated from ground. I think it would have to be for the points opening/closing to have any effect.
The points provide path to ground, so the primary can build a magnetic field. If grounded all the time, the field would never stop being made, except as the power faded away on a magneto, which I think would not generate any spark.

Points close, allowing mag generated juice to build a field in the primary.
Points open, collapsing the field, inducing spark in secondary.
Primary and secondary can share a ground using the bare wire.
The wire with the ring terminal would likely be the kill wire, grounding the output from the magneto so no primary magnetic field is generated.

tom
 

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Here are a couple of pictures showing what tomw0 described. My engine is currently on the bench after a refresh. Notice the insulator he mentioned. The wire coming off the top going to the right is going to a switch I have setup going to ground. So when I want to stop the engine that switch takes the magneto to ground as tom0 described.

So there are three wires on that insulator. 1 goes to the points, 1 goes to the magneto and 1 goes to my switch. So the wire that goes back to the magneto usually attaches to that short wire you asked about coming out of the magneto. The attach point is usually a stud on the shroud and it should be isolated from ground.
IMG_6587 (1).jpeg
In my case there was so much corrosion around mine that I had some continuity to ground so I had to clean up that connection point. otherwise it didn't matter what position my switch was in the magneto was always grounded.
IMG_6819.jpeg
IMG_6818.jpeg
 

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Discussion Starter #24
Update: This engine has a new coil and has the proper airgap. yesterday I installed a new Nova ll directly from the coil tab. One wire, not through any shroud covers or such. NO SPARK!!
to recap:
It sat for maybe two months and did not start. Found a huge mouse nest around the coil. Coil had bite marks, but did not appear to damage wires.
Put a new coil on anyway. Did not start. No spark.
New condenser and new points, gapped at .02. No spark.
Installed Nove ll ....no spark.
Flywheel is magnetic. Verified.
What am I missing??

H E L P ! ! !
 

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Discussion Starter #25
I reinstalled the old magneto coil. Cleaned all the surfaces. Checked continuity...all is good. Verified with new coil. Same. Installed known good plug. Tried it with both coils....NOTHING! My son suggests the flywheel might have sheared the key. Maybe. but would it not still have a spark to the plug?? Although mis-timed, it would still spark....I have an induction timing light on it for now for no other reason than to verify spark/no spark. Tried .014 to .018 air gap. Nothing. Wiring from coil to Nova ll is a one piece going through nothing by air. Nova ll is well grounded.
I am at a 100% loss.
Any help, suggestions...any thing would help.
 

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What's the gap between flywheel and coil? I just use a business card. Don't connect kill (snipped) wire to anything. Do ground coil ground connector) Connect spark plug laying on it's side (grounded) see if it sparks.

Sent from my SM-S205DL using Tapatalk
 

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Discussion Starter #27
There are but two wires from the coil. One to the plug, the other to either the old style points/condenser or to the negative terminal of the electronic Nove ll. There are no other wires involved. I did the business card. Did the brass feeler gauge.
At wit's end, Sevenhills 1952. There is a donor Briggs that I may swap flywheels with. No where else to go with this.
 

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It has been years since I last used a Nova II module,but I seem to recall the instructions saying you could swap the two wires on it that go to the coil & ground,if it had no spark,some engines need the polarity reversed..and that they won't work on some coils with 3 armature legs..

The flywheel key does need to be intact,in order for a spark to be created..though one that is only partly sheared or completely sheared let the flywheel be "out of time" with the crankshaft and still make spark,the spark intensity will be reduced and the engine may not even fire on starting fluid if its far enough "off"..

There is a "edge gap" effect on magnetos that require the events to occour at the proper time to get full spark voltage and have it happen at the correct position before top dead center..you can find a long explanation online about this..my small engine book has 2 full pages on magneto operation and theory--I understand about half of it..

Also,if I haven't mentioned it already,the coil can be mounted "wrong side out" and create a no spark condition...I've done it more than once,and it drove me insane for a few days till I finally discovered my mistake,by looking at a similar engine I had that ran good and saw the coil was on "backwards" !..
 

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Discussion Starter #29
Interesting stuff, Tractor-Holic. More than a few people commented about a compromised key. So....I finally got to it this afternoon, reluctantly, but I did it. Pleased that I don't have t' purchase a new key. Nothing wrong with this one. Not an expert, but, I see it like this: I could mount ONLY the flywheel on a bench mounted shaft. No engine included. No key'd shaft. And a coil mounted the .018 away from it. There's the Nova ll connected with it, too. And Nova is grounded to the spark coil frame. Spinning the flywheel more than the minimum 320 rpm required for energy generation, there should be a spark from the plug wire from that coil. Am I correct in that assumption?
I don't know where to go from here, shy of purchasing a new engine. It has all new components. And various mixes of old with new components results in the same no spark condition.
Seems like there's nothing wrong with anything, yet.....
 

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Discussion Starter #30
It's been five days. Since epxperts are stumped, that leaves me, the one on the lower rungs of the ladder, with nothing left but to acquire a 12.5 Kohler from my tractor stash. Will miss the fuel sipping of that Briggs. Maybe I will approach it again next year. I gotta get Mr. Splitter back up and running!
I appreciate all the help and suggestions.
 

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Discussion Starter #31
Update:

So...you all can just SHUTUP!!! After a new coil, new points, new electronic ignition (Nova ll), tried several 'known' good plugs....NOTHING WORKED! So..on a whim, I put all the old stuff back on, except the Nova ll, and tried it again t'day. Still nothing. So...(here's where my embarrassment will be magnified by ANY comments on my engine capabilities...) I put in ....
A BRAND NEW ...STORE BOUGHT ( !! ) sparking plug! WHOA!! What's THAT sound???!!!!
Okay....I'm braced here... Let them rip....
I deserve it all. And yes, I can take it.
My forehead is pretty flattened now....
 

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Heh heh heh It goes that way sometimes.....Glad you found the problem. I still recommend the Nova module as it will improve your engine's performance.
 

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Discussion Starter #33
Yes, Dee-, the Nova ll is the only new part to the system. Oh ...and the stoopid sparkplug.....
I hope the engine mounting bolts will hold. I may ave worn the threads down as many times as it's been re-re-re-re-mounted.
I really appreciate all the help from all on this project.
 

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I was having issues with a tecumseh vtwin. Had a dead cylinder , then two. After fixing a rocker arm issue I was still running on one cylinder but I thought it should have been the opposite one. Then I recalled that I had switched the plugs that had been taken out to set valves easier. Switched the plugs and the dead/good cylinders switched. New plug on dead side and it became alive. Puzzling though was fact that both original plugs had been new ngks. Also more recently working on a briggs snowblower engine. Heck of a time restarting it after any period of running, even just a minute. New plug appears to have fixed that.
 

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just a note you got gas you got fire you got run most the time. I always go to a extra plug I carry in stock change out plug --while out plug wire on and plug laying on its side to insure grounding to see if the new plug is firing--new plugs don't fire sometimes. I'M so happy for you. good work looks like temps getting below freezing before long.
 

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Spark plugs can sometimes spark perfect outside of the engine when you check for spark,,but once installed,the compression can "blow out" the spark if the spark is weak or the plug is defective or fouled..
Old spark plug cleaners had a tester that used compressed air to also check for that as well as sandblast them clean..
 

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" compression can "blow out" the spark "

Never heard that one .....
Well you have now .
The resistance of air increases as an exponential value of the pressure.
So when the pressure gets high enough he spark can not jump the gap
If you are old enough you will remember seeing the old Champion spark plug testers at service stations
That is exactly what they did.
You watched the spark through a perspex window while the machine increased the pressure till the plug stopped firing .
Thus the "old timers" description of "blowing out" the spark.

The other thing that happens with modern plugs that are not glazed and modern fuel which is very conductive at cylinder pressures is the resistance of the gap ends up being greater than the resistance of tracking down the fuel damped insulator so again no spark.
 

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I've had coils that would spark an inline tester that was grounded but not when attached to a good installed plug. New coil would fire that same plug.
 

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I've had coils on Tecumseh's that fired a plug fine when you laid it on the outside of the block to check for spark,but not be strong enough to fire the plug installed under compression..
Some of those engines I could make run for awhile by installing a new non-resistor spark plug,but they would usually stop running rather suddenly after the plug was a few hours old,like it developed more resistance as it was being used...a new coil was the only way to fix it permanently..
I think the coils get "cooked" being under the flywheel on those old Tecumseh's,instead of being mounted above the flywheel where its in the path of the air flow from the flywheel's cooling fins..
 
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