dead magneto

[Jugster]

My magneto won't keep the engine running except at high RPM's, so running on magneto is no longer practical. Looks like I need to recharge the magnets. I suppose I'll get to that eventually, but not now as it requires three 12-volt batteries, the cables to connect them in series, etc. (I mean who the heck keeps three fully-charged 12-volt batteries?). Anyway, my car has a 12-volt electric system with an alternator, so my question would be the following: Is there any harm to running the car on battery and alternator instead of the magneto?

[mtntee20]

Bob, I have to say NO. Our TT does not have a magneto in it, so it's battery all the time. Haven't seen any detrimental results to date. Our delivery truck has a magneto and it DOES run better on mag. than on battery. THUS, I expect the TT might run better as well IF it had a mag. but haven't had any problems on battery. BTW the absence of a mag. was NOT my decision. We bought it that way. IF / When the engine needs work, we will likely put a mag. in at that time.

[Moxie26]

Have a qualified chapter member calibrate your coils. .... What is the AC voltage reading at speed?.... If you do decide to recharge the magneto, asking around to borrow 12-volt batteries, isn't that bad , just be sure to use battery cable connectors to hook up positive to negative between the three batteries..... I doubt you'll have access to six 6 volt batteries.

[speedytinc]

No.
Look for the past thread from Tom Carnege on recharging. A DC arc welder does the best charge.

[speedytinc]

Have a qualified chapter member calibrate your coils. .... What is the AC voltage reading at speed?

It is remotely possible that coils set with a lower amp draw will still run on your magneto.

[JTT3]

Bob was this a sudden condition or just over time? You may want to take the transmission inspection plate off & have someone rotate the engine by hand crank and see if all your keepers are still attach to the magnets or if loose by sight or using your hand for the last part. It’s tight but can be done. Have you tried to see how much you can move the crank forward yet?

[jsaylor]

RE: Extra Batteries - One from your 12v T, 2 from your modern vehicles.

[signsup]

When your other hobby is military vehicles, most of which run off two 12v batteries connected in series to run 24v electrical systems, you will always have a supply of 12v batteries. One WWII jeep and one WWI ambulance are the only vehicles I have that use 6v batteries. But, I also thought there was a way to zap magnets using a welder?

[Craig Leach]

Hi Bob,
3 12vdc batteries in series is 36+ volts? I have heard people say 12 volts DC is more than enough to run coils on? How does the alternator
charge 36 volts??? How do you separate the 36 volts from your lights? Have you checked the endplay on the crank? Checked the mag gap?
John may be on to something if it takes 36 vdc to get spark?
Craig.

[Ed Fuller]

One of my non generator T’s has a non working magneto. I have run it for years on a 12 volt battery powering the coils. Runs just as good as my other T’s do that have a working mag. No special coil adjustments either.

[Moxie26]

Craig : ..... The 36 volts DC with series 12 volt battery hookup is in the magneto recharge procedure.

[browning]

Find a friend with an electric golf cart. Connect across as many batteries as you need to get the voltage you want. 8 volt batteries will yield 8-16-24-32-40 or 48 volts and they are deep cycle to take the heavy load.

[signsup]

I'm gonna show my ignorance here, but if it is only volts needed and not amps, if any 12v batterys would work, riding lawn mowers, gas golf carts, etc might be a source. Or, if a friend has a Super Duty pick up truck or larger, they often have two batteries under the hood. Or come on over to my house and take your pick from my green machines.

[Steve Jelf]

How does the alternator charge 36 volts??? How do you separate the 36 volts from your lights?

The 36 volts are not connected to the lights, charging system, or any other part of the functioning car. They are used only a few seconds for flashing the mag coil to recharge the magnets. See the diagram posted above.

[Jugster]

My thanks to those nice folks who replied to my question. In answer to some of the questions:

My magneto has always run the engine with less authority than the onboard 12-volt battery. As of late, it has become more noticeable and now the engine won't run on magneto except at high RPM. That tells me it isn't broken, but weak. I suspect the magnets need to be recharged.

No, I don't know how to test to see how far forward I can move the crank. I sure do hope this is not an internal wear problem.

Craig, my understanding is that the 36 volts of the three 12-volt batteries connected in series are used to momentarily "flash" the magnets in the magneto while the engine is still in the car. It is done by connecting the positive to the magneto post and momentarily touching the negative cable to the engine block. This "recharges" the magnets in the magneto. Normally, my single onboard 12-volt battery and its alternator run my lights and electric starter—and now, they run my ignition system instead of my dead magneto.

[Craig Leach]

Hi Bob,
Sorry I miss read the statement If you jack up a rear wheel & turn the engine over in high gear pushing in hard on the crank, then have
someone push on low peddle while watching the crank pulley if there is endplay you should see the pulley move. I have one engine that is so
loose the crank can be seen moving front to back just by pushing low pedal from high to low it moves 1/8'+
Craig.

[SurfCityGene]

As Johnny posted earlier.. Use Tom Carnegie's method for In the Car charging!! It's quick and very easy and will give your magnets the best charge possible! A DC welder with a quick strike is all it takes. Simple and Super effective!

[signsup]

I thought I had heard there was a welder way. Thanks for not keeping me thinking I was crazier than I actually am.

[Jugster]

Okay, so let's say I get my car to a welding shop for the purpose of re-magnetizing my magneto magnets. They're not going to let me handle their equipment, so what instructions do I give these guys? How does one go about this operation?

[Jim11787]

Bob. I sent you a text the other day. I have a DC wire feed welder. Looking at the diagram we just hook up ground and spark the magneto post. Maybe others can confirm.

[JTT3]

Since you didn’t say anything about the keepers I’ll assume everything is good on that point. If you do the DC welder technique, you should consider having the positive held steady on the contact on the field coil & use your negative to complete the circuit, it’s only a tap anymore duration at one time can cause the solder on the contact to melt. Not good. In addition prior to doing that I’d wrap something non conductive around the metal rod that you’ll have the positive hooked to, perhaps an old Phillips screwdriver that’s seen better days. The reason behind doing it this way is once you take the magneto post off the hogs head you’ll notice the hole is small and you don’t want an errant movement that may contact the hogshead. JMTCW.
Best John

[Steve Jelf]

Jim, I believe it's better to hook up the post and flash the ground. Less chance of damaging the button.

[Jim11787]

Jim, I believe it's better to hook up the post and flash the ground. Less chance of damaging the button.

Thanks Steve. Makes sense.

[Jim11787]

Since you didn’t say anything about the keepers I’ll assume everything is good on that point. If you do the DC welder technique, you should consider having the positive held steady on the contact on the field coil & use your negative to complete the circuit, it’s only a tap anymore duration at one time can cause the solder on the contact to melt. Not good. In addition prior to doing that I’d wrap something non conductive around the metal rod that you’ll have the positive hooked to, perhaps an old Phillips screwdriver that’s seen better days. The reason behind doing it this way is once you take the magneto post off the hogs head you’ll notice the hole is small and you don’t want an errant movement that may contact the hogshead. JMTCW.
Best John

John thanks. A question you may be able to help me understand better. I got my welder from a friend and have used it a few times to make some minor repairs but have no formal training. It is a Lincoln weld park 100 wire feed welder. I did check and it was DC. Is this type of welder suitable for this task or do you need a stick welder? I would think the current flows through the wire material used for the welding and arcs off instantly. If this is the case I’m not sure how it would be used for this task. I can see a stick welder positive side clamping on the magneto post and touching the ground to recharge the magnets, but don’t know if a wire feed welder could be used.

[Dan Haynes]

Further to Steve's thoughts, I use a small pair of Vise-Grips to grip the nut on the top of the magneto post and connect the jumper cable to the pliers, so I don't accidentally arc on the tiny threads of the contact post. Then strike the ground to the hogshead.

[JTT3]

First I’m not sure I’d use the mag post. I would take the mag post off, others that have used the mag post should comment. If you read the post I made prior to Jelf’s you see that I spoke to that point but as the young folks say you do you. Using a DC wire welder can be used IF YOU HAVE THE ABILITY TO REMOVE THE FEED GUN AND CONNECT ANOTHER CABLE TO the connector where the cable & gun connected. You’ll also need to remove the wire spool depending on how the wire welder works. You don’t want wire unspooling ha. Remember if the wire feed cable/gun is capable of being remove and another lead connected when turned on you are hot till the power is off.

[Jerry VanOoteghem]

Why can't you just flash it with one 12V battery?

[jab35]

John: For the MIG, how about disabling wire feed and making/installing a copper stud that fits the thread in the torch nozzle tip that the wire passes thru. (Remove brass bushing/install solid copper stud in torch tip.) The stud serves as the torch contact, ground clamp completes the circuit. Pulsing current is done with nozzle trigger. Has anyone tried this? jb

[Craig Leach]

Interesting Idea James. Most of us have a MiG welder now days I wonder if the lower frequency of a MiG welder would make a difference?
Keep in mind that some less expensive MiG welders are AC to save the cost of the rectifier.
Craig.

[George Mills]

Hey Bob,

Just sayin...it seems you are saying that most of the time it does not work on mag, and some of the time it works but feeble on mag? Did I get that right?

While everyone else is suggesting a full magnet recharge...I'd say try something else first, it may not help but it is fairly easy and relatively cheap so in my world, why not?

Pull the magneto post and clean it and see if it actually seats in the glob. Or, just try a different magneto post! Simple as it sounds...I have had experience where there was a really baffling inability to run on mag, I cleaned it - still baffling - Moxie 26 happened to be there that day and as usual, he can rebuild a T from his car trunk. Tried a different mag post...the thing ran like a champ...go figure, never figured out why the old post didn't (I think its point had wallowed in the glob...but only think.). Worth a check?

[speedytinc]

Further to Steve's thoughts, I use a small pair of Vise-Grips to grip the nut on the top of the magneto post and connect the jumper cable to the pliers, so I don't accidentally arc on the tiny threads of the contact post. Then strike the ground to the hogshead.

NO,NO,NO. Remove the mag post connector. Contact the mag lead button directly. (An old valve with some rubber hose for an insulator.) If you go thru the mag post you turn the spring into a heating element & at the very least lose the spring temper.

One 12V battery isnt enough. I have had marginal success with 3 12V batteries.

The Tom Carnege method is the most successful & quickest method I have seen & done. Magnet saturation is achieved in 1 strike if the field coil is good.

[waterloo]

As an electrical expert I have to ask what position the flywheel needs to be parked at for this to work? Also please note that magnetizing happens when the current suddenly drops, i.e. stops flowing, as when you remove the connection. It should not be necessary to have current flow more than a second.

[speedytinc]

As an electrical expert I have to ask what position the flywheel needs to be parked at for this to work? Also please note that magnetizing happens when the current suddenly drops, i.e. stops flowing, as when you remove the connection. It should not be necessary to have current flow more than a second.

You can do the compass dance if you use the old method pictured. Unnecessary.

Read the Tom Carnege post.

Look @ the magnet keeper screw ends, they must be centered in relation to the mag post. Either method.
Easily seen with the inspection cover removed. That centers the magnets over the charging coils.
You are correct, one quick strike does the job. 2 or 4 doesn't improve the charge using a hi amp DC arc welder.
But we just cant resist. More is better?? Not here.

[Steve Jelf]

The in-car charge will work (I've done it with batteries), but recharging is best with the magnets off the flywheel, one at a time (I've done that too). I'd go with the in-car charge until there's some other reason to dig in deep.

[Dan Haynes]

Further to Steve's thoughts, I use a small pair of Vise-Grips to grip the nut on the top of the magneto post and connect the jumper cable to the pliers, so I don't accidentally arc on the tiny threads of the contact post. Then strike the ground to the hogshead.

NO,NO,NO. Remove the mag post connector. Contact the mag lead button directly. (An old valve with some rubber hose for an insulator.) If you go thru the mag post you turn the spring into a heating element & at the very least lose the spring temper.

One 12V battery isnt enough. I have had marginal success with 3 12V batteries.

The Tom Carnege method is the most successful & quickest method I have seen & done. Magnet saturation is achieved in 1 strike if the field coil is good.

If the coil spring is turning into a heating element, you are holding it way too long and you need to learn to flash the connection. If the spring is glowing red as John says, the solder between the individual coils (which melts at a far lower temperature than red-heat for steel) will be found in a puddle at the bottom of the crankcase and the cloth insulation wraps burned off the copper coils.