Aftermarket Magneto

GoldenMotor.com
Jan 21, 2015
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Portland, Oregon
I am now convinced that the stock magneto was made by Satan. I do not want to buy another one. Instead, I want to get one that was made for a chainsaw or a weed whacker or something. Hopefully that would be higher quality and won't fall apart in a week. Anyone done this before? Anyone know what magneto to buy? Or how much it ups the current? Or anything about it? I'm going to a small engine shop tomorrow with the magneto to see if I can find a replacement. Just to be clear I no longer want troubleshooting tips or things to fix the stock magneto, I want suggestions for better ones. Any help much appreciated.
 

cannonball2

Well-Known Member
Oct 28, 2010
3,682
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Colonial Coast USA.
There is no better one,
except the newer no white wire magnetos have not failed for me yet.
I agree, the ground is now on its own terminal and has a substantial jumper to the mags frame. The earlier units had the small fragile wires soldered directly from the coil to the frame. I believe the inherent vibration of the engine fatigued them. I had one fail last week, it was at the ground. if you probed just inside the coil you could get the proper ohm reading. I couldnt repair it.

The newer mags are being sold along with the older models. You can recognize them by having only black and blue wires, the aforementioned ground jumper and the covering over the windings is white. I bought one today for $10 shipped.
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
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Phoenix,AZ
I agree, the ground is now on its own terminal and has a substantial jumper to the mags frame. The earlier units had the small fragile wires soldered directly from the coil to the frame.

The newer mags are being sold along with the older models. You can recognize them by having only black and blue wires, the aforementioned ground jumper and the covering over the windings is white. I bought one today for $10 shipped.
Yep.
The new mags don't have a secondary coil for aux power, hence no useless white wire and split ground.

I haven't actually pulled both apart and looked but the new mags either have a bit fatter wire, or more of it.

Just remember that a magneto is just a coil to make a pulse from a spinning magnet.
Crap magnet, crap spark, and yes permanent earth magnets loose their magnetism, sometimes in short order.

I had a new kit with a magnet that would barley hold it's on weight on the side of metal filing cabinet.
Even with replacing stock wiring and using a really good plug the thing couldn't maintain a good timed sparked.

If it's a good strong magnet it should be a pain to get the magneto mounted because of magnet pull.

I'm talking hard to get the first bolt in, and then even harder to align the mag with the other bolts to keep the same air gap between the magneto coil and magnet, which has to be right for the most output to the CDI.

The bottom line here is you want the biggest damn spark arc in your cylinder as you can get, and that starts with the spinning magnet which also sets the spark timing.

I don't dick around with that, I make sure I get every milliamp the coil will make to the CDI by replacing the stock wiring and using an Iridium spark plug.

It's amazing the big spark with the big gap those plugs have even with a not really strong magnet.
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Are you looking for a better 'magneto' or an ignition module? When you say "magneto" that is referring to the rotating magnet, or rotor and the 'U' shaped frame and coil that the rotor spins inside. These parts are located under the left side engine cover.

The CDI is the seconday part of the ignition system. And no, there isn't anything better than the stock one. There are aftermarket replacements but there has never been any proof, other than advertising hype, that they are superior in any way to the stock, kit, CDI.

Multiple failures of either part can usually be traced to improper installation. It would rare indeed to see multiple magnetos or a CDIs fail in less than a week unless something isn't installed correctly. Exposure to moisture can be a problem however. There are many ways to avoid water damage.

Can you be more specific on what is happening and maybe a photo or two of your engine?

Tom
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
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Central Area of Texas
Are you looking for a better 'magneto' or an ignition module? When you say "magneto" that is referring to the rotating magnet, or rotor and the 'U' shaped frame and coil that the rotor spins inside. These parts are located under the left side engine cover.

The CDI is the seconday part of the ignition system. And no, there isn't anything better than the stock one. There are aftermarket replacements but there has never been any proof, other than advertising hype, that they are superior in any way to the stock, kit, CDI.

Multiple failures of either part can usually be traced to improper installation. It would rare indeed to see multiple magnetos or a CDIs fail in less than a week unless something isn't installed correctly. Exposure to moisture can be a problem however. There are many ways to avoid water damage.

Can you be more specific on what is happening and maybe a photo or two of your engine?

Tom
Ditto....100%

Over 5 years now of running several differrent HT engines and I have never had a magneto go bad and I've yet to have a CDI go bad with exception to the first HDs Lightening CDI I had that burned out in less than 10 miles.
 

Davezilla

New Member
Mar 15, 2014
2,705
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San Antonio Texas
Are you looking for a better 'magneto' or an ignition module? When you say "magneto" that is referring to the rotating magnet, or rotor and the 'U' shaped frame and coil that the rotor spins inside. These parts are located under the left side engine cover.

The CDI is the seconday part of the ignition system. And no, there isn't anything better than the stock one. There are aftermarket replacements but there has never been any proof, other than advertising hype, that they are superior in any way to the stock, kit, CDI.

Multiple failures of either part can usually be traced to improper installation. It would rare indeed to see multiple magnetos or a CDIs fail in less than a week unless something isn't installed correctly. Exposure to moisture can be a problem however. There are many ways to avoid water damage.

Can you be more specific on what is happening and maybe a photo or two of your engine?

Tom
Fully Agreed as well... The only mag failure I've experienced was a defective unit installed on one of my engines, replaced the mag and it fired right up and still running perfectly. The CDI is the same one I started out with and it's running rock solid as well.

Need more details or even pics of the installation you're doing so we can see exactly what's going on. I can see one burning out or coming in defective but not multiple failures in the same week unless something else's going on like improper installation or you're letting the components get wet...
 

MotorBicycleRacing

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Jul 28, 2010
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I agree, the ground is now on its own terminal and has a substantial jumper to the mags frame. The earlier units had the small fragile wires soldered directly from the coil to the frame. I believe the inherent vibration of the engine fatigued them. I had one fail last week, it was hat the ground. if you probed just inside the coil you could get the proper ohm reading. I couldnt repair it.
Exactly.
The winding on the metal frame was not tight so it could move up and down from vibration which broke the thin ground strands.
Had a lot of failures before the new mags came out.

PS: You can fix them by taking the white wire and grounding it under the mounting screw along with the black wire.

This is basically the same way the new mags are wired.
 
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cannonball2

Well-Known Member
Oct 28, 2010
3,682
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Colonial Coast USA.
PS: You can fix them by taking the white wire and grounding it under the mounting screw along with the black wire.

This is basically the same way the new mags are wired.

Thanks MBR I will dig it out of the trash and give it a try!
 

Huffydavidson

STREETRACER/MANUFACTURER
Jan 29, 2012
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st.louis,mo.
And Map that wasn"t a lightning, it was a early performance CDI that Ivan H and I worked on. NOT TODAYS HD LIGHTNING. Witch has ZERO failures .
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
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Central Area of Texas
And Map that wasn"t a lightning, it was a early performance CDI that Ivan H and I worked on. NOT TODAYS HD LIGHTNING. Witch has ZERO failures .
oh yeah i know it wasnt the current model Im still running the current model and it has performed without a single issue, bike runs great with it.

Like Ive said , its the best of all of them on the market and if that's what someone wants instead of the stock unit its the one I recommend.

Not hating on the product at all Dan, it is a quality piece.

Map
 

Huffydavidson

STREETRACER/MANUFACTURER
Jan 29, 2012
1,076
4
38
st.louis,mo.
Thanks Map. I have a secret weapon if they ever figure out how to copy the lightning. Its tested and proven only with my son and I will not unveil it. So if they can successfully clone it my vendors and I will still be HD#1
 

Davezilla

New Member
Mar 15, 2014
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Thanks Map. I have a secret weapon if they ever figure out how to copy the lightning. Its tested and proven only with my son and I will not unveil it. So if they can successfully clone it my vendors and I will still be HD#1
I'm definitely glad to hear there's a continuous improvement on something instead of a lot of crying when something gets copied.... good to see you got a way to edge out the competition if it does happen.
Nowadays its so easy for someone to buy someone else's hard work doing all the r&d work and refining something until its good enough to sell then send it to China to be mass produced... ya pretty much have to have a better version ready by the time ya got the original good enough to produce and sell.
 

Davezilla

New Member
Mar 15, 2014
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San Antonio Texas
Yeah sadly the CDI will work only as long as the dastardly magneto does.
Yup...the cdi and coil can only put out the same amount of energy the magneto and mag coil can feed into it, and actually slightly less since nothing works at 100% efficiency. We can convert current into voltage or voltage into current, but the total power will remain the same. Now if someone makes a battery powered amplifier circuit to feed more power into the cdi or ignition coil similar to what MSD does we could get a stronger spark that could take advantage of running a wider plug gap.
I've been out of the electronics industry for over 25 years so Im pretty rusty in that area, but much stronger in other areas so that's more what I'm focused on... there has also been massive improvements in some electronic components in general so it would take me some time just to catch up on all the newer stuff that's way more efficient than it was back in the early 90's. Some of the stuff is still the same but stuff like power transistors and mosfets not to mention capacitors have improved massively in that timeframe... I remember when I was in electronics school back in 88 there was no such thing as a 1 farad capacitor, or if there was one, it would have been the size of a full sized car ....
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
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memphis Tn
Jim Wilson at Pedalchopper is now offering the Screaming Roo mag coil and CDI combo for sale.
Supposed to be a higher output coil which is used with a larger upgraded CDI for better stronger spark...
Judging from the reviews I have seen, those 'Roo guys are doing it right.
Worth a look for anyone seeking a bigger spark.
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
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Phoenix,AZ
PS: You can fix them by taking the white wire and grounding it under the mounting screw along with the black wire.

This is basically the same way the new mags are wired.
Ohh my...
Ground the white aux wire to make it go better?

ANyway...
It is all about the actual spark.
The plug makes it.

A plug designed to make big spark across a big gap even with not much power is king.

I just had a new customer ride by on his MB to get a new CDI for his buddy and he asked about his top speed and power.

Said that stock straight head 66 could barely do 30 and asked about a new carb.
I took a look and he had some Champion plug in it.
I put in a new NGK 5944 Iridium for $10.

He called me when he got home.
Suffice it to say he was pleased, got him 5 MPH more sustained for $10.

Just something to keep in mind when it comes to something to ignite a compressed gas/air mix, you don't need an arc weld spark, just one long one delivered when it should fire (timing).
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
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Littleton, Colorado
Oh come on, KC. Give me a break here. 5MPH increase because of a spark plug? A plug designed solely for high milage, not performance increases? And please don't post that stuff from NGK about their overpriced plug and how much better it is than a standard one. I've seen it, read it before and I'm not impressed.

Yes, those expensive spark plugs have some advantages, if you're concerned with getting 100K plus miles from them, but to say, or even imply that they will increase performance enough to provide a 5 MPH improvement over any other plug is just ludicrous.

You and the others who sell them have a financial interest. Who wouldn't want to sell something costing three or four times more than what could be used just as successfully? I certainly would if I was in the business of selling spark plugs. However, I'm not.

Personally I resent you pushing this plug on new and uninformed members who come here looking for advice and are prone to listening to what is offered. Tell them the truth. If they want a plug that might last for over a hundred thousand miles, fine. But do not try to tell them that they can expect neck snapping performance just because they spent nearly $10. for a spark plug for a $100 Chinese bicycle engine. A $2.00 plug will do everything your overpriced wonders will do, and just as well.

Tom
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
Ive been using Champion spark plugs in all my lawn equiptment, garden equipment, chainsaws and even some vehicles and Ive always had good results with them.

I always ran Autolite Plugs in my high performance high compression chevy engines, they just held up better and most all the drag racers around here also used Autolite plugs in their cars.

Spark plugs dont add performance aor speed all they have to do is deliver a good spark to ignite the fuel....lol

Port work, good balance, good exhaust, correct carb and it being tuned right, correct timing good compression.

those are the things that keep, help and add performance.

Yes better hotter firing ignition is good, but I personally haven't experienced anything that does it any better for my engines than the stock cdi/coil.

and like I have said and will say again, the HD's Lightening CDI offers as good of performance on my engines as the stock unit, I have honestly seen to top speed increase but its the only aftermarket cdi I've used that didn't reduce performance.

Tom I agree with you completely about spark plugs.

KC, if that fella actually did realize 5 mph speed increase from having a new spark plug he could have realized it with any good condition spark plug....