I want to run points in my old shovel but I have dual plug heads...can a set of points fire two coils....any info or wiring diagrams would be appreciated
Couple ways to do it. There are point systems that use two sets of points in a single fire configuration that can be wired to a set of dual output coils with 5 ohms of resistance. Another way to do it is with one set of points and a set of dual output coils with 2.5-3 ohms of resistance.
2 E/I coils @ 3ohms in series would give you 6 ohms which is one ohm off a factory point coil.
Problem is I don't think you will get full spark energy, even though you would have E/I coils they will not get full current in series.
I tried to post a picture but can't so here goes ....to wire two 3 ohm coils in series I run a wire from points to the (-) terminal on the first coil then from the (+) terminal from the first to the (-) on the second coil then (+) from second coil goes to battery/switch...this is in series and will give me 6 ohms? What if I use two 5 ohm coils run a wire from the switch to the (+) terminal of both coils then from the (-) side of each coil (using two wires) run separate wires to the points?Also where would I find a dual point set up (forgot to say this is a cone motor) for a shovel head ? This was my first choice but can't find one...sorry post is so long but electricity makes my head hurt....thanks for your time and help....
OR, you can just run one plug per head with just a single point set if your compression is under 9.5:1 . As mentioned, Spark quality would be questionable if 4 plugs were used. Duel points works & you can put the condensers up by the coils, but not sure where a duel point plate can be found now days. I tried it years ago before the electronic age came about & used a Dyna volt pack as the condensers, good quality spark that way. BUT!!! Why not just go with a modern single fire? more compact, more reliable more accurate, to many ++'s to ignore.
Quote from: Burnout on August 16, 2021, 08:58:06 PM
2 E/I coils @ 3ohms in series would give you 6 ohms which is one ohm off a factory point coil.
Problem is I don't think you will get full spark energy, even though you would have E/I coils they will not get full current in series.
How about closing the gap on the plugs. I used to set my AC 44's at .022 when I was using a Joe Hunt magneto. It increases the duration that the spark is held and it takes less to set it off. We're talking tiny increments here but it sure made a difference for me as a kick start.
That works with a mag because they have poor spark output at low speeds, then as the rpm comes up they turn into a welder.
Using a pair of E/I coils in series the best spark will be at low speeds and then it will degrade as the rpm increases because the dwell time is shortened.
So less charge current, and lower output as rpm increases, exactly when you don't want it!
Well thanks to all for the ideas ....maybe I will just run one set of plugs and coil...again thanks all for your time
With points that is likely the best way to go.
Save up for an Ultima Ignition without the coil and use two stock E/I coils.
And do install a VOES for the full effect. :bike:
Quote from: Burnout on August 19, 2021, 08:37:02 AM
With points that is likely the best way to go.
Save up for an Ultima Ignition without the coil and use two stock E/I coils.
And do install a VOES for the full effect. :bike:
Taking a crane hi-4 out don't like it going back to point
Unless the Crane is a dud, it should work fine. What were your problems with it?
I'm thinking there may be a problem with the install or setup.
What kind of coils and how was it wired and did you use a VOES?
At one time that was the gold standard ignition.....
Going to points from a good properly setup HI4 will be a step backwards.
You are going to loose the 3D spark advance, it may not start as well or run as smooth.
I replaced a Dyntek 2000i ( dual plug, single fire) at 33,000 miles with the Ultima knockoff. I appreciate the electronics over the original points set up but eventually like everything else they will fail. I used to carry all kinds of tools and a spare points plate assembly on that bike. These days I am fine with a cell phone and a credit card. The truth is that in 27 years with my 76 I've only needed a trailer twice. Once was for a failed kill switch and once due to a hit and run.
Why do so many say E/I ignitions fail?
The first generation Harley electronics, were total garbage. And there are some really lame aftermarket units.
An Ultima, a Crane (they are no longer made), a Dyna, or a Daytona Twin Tech should last longer than you will likely live.
I cannot remember ever having to replace an E/I unit that actually failed in service, most are ruined by improper installation.
Lots of folks remove the factory ignition and I horde those and put them on points bikes,
the factory ignition is very robust and works great on a stock bike, it's only weakness is the sensor in the cam cover.
And the sensors seem to fail softly giving plenty of warning before the bike won't run.
Often a bad sensor can be spotted by looking to see if the potting compound is dripping out of the sensor. (tapping on it with a screwdriver handle like a TC sensor)
OR, you could consider a Dyna Ignition Booster:
https://bikerdirect.com/electrical-battery/ignition/ignition-point-kits/dyna-ignition-booster-for-classic-xl-single-point-harleys?_vsrefdom=adwords&gclid=EAIaIQobChMIpo2V0cfA8gIVfj6tBh3hqweREAQYBCABEgJvHvD_BwE
I used one of these on my Airhead BMW when I converted it to dual plug heads. It allows you to run two 5 ohm coils in parallel. So you don't lose any spark energy (voltage), and the pulse to the coils is more like that of an electronic ignition. And, the current through the points is very low, so they will essentially never wear/burn out.
One could also argue if you're going to that end, why not just go full E/I?
-JW
Quote from: Burnout on August 19, 2021, 09:04:07 AM
Unless the Crane is a dud, it should work fine. What were your problems with it?
I'm thinking there may be a problem with the install or setup.
What kind of coils and how was it wired and did you use a VOES?
At one time that was the gold standard ignition.....
Going to points from a good properly setup HI4 will be a step backwards.
You are going to loose the 3D spark advance, it may not start as well or run as smooth.
Hard to start cold (kick) ....just like points....
I ran points with dual plug heads ,I ran 2 , 6 volt coils I forgot how to run the wire but you should find it here
You would connect 6v coils in series.
I would check the ohms across them though.
Dyna sells 2.2 ohm coils for this I believe.
A pair of DC4-1 coils in series will work with points and dual plugs.
Dynatek says
"In theory, the DC4-1 coils could be used, but you likely will see point wear and diminished spark output and energy, not something you want on a drag bike.
With a point ignition, you ideally want to use our Dynatek DC2-1 coils along with our Dyna points Booster system, number DBR-1.
The Booster will keep the points happy with the coils and also allow a very nice increase in spark output and energy, "
But if you look up the DC2-1 coil it has a 1.5Ω coil if that booster will run a coil that hot you could easily drive two stock 3Ω coils still get a boost in spark energy as well as a wallet that is not so light. But the booster is still $150, it's less than another week's lunch money to step up to an Ultima.