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Magneto Test

Posted: Wed Jul 26, 2023 7:16 pm
by pspete
Following all the instructions with the light bulb and analog meter etc. but not comfortable with this meter yet so not sure if I'm reading it correctly.
Please help.
I think I'm seeing 8v @ idle, 16v moderate rpm, 19 fastest rpm.
Sorry about the orientation but it's the only way they would load.
Idle.jpg
moderate.jpg
Full.jpg

Re: Magneto Test

Posted: Wed Jul 26, 2023 7:24 pm
by Scott_Conger
pretty much, yep.

Re: Magneto Test

Posted: Wed Jul 26, 2023 7:43 pm
by pspete
Thanks.
So the reason it runs like crap on Mag under load compared to on Bat has nothing to do with the mag...

Re: Magneto Test

Posted: Wed Jul 26, 2023 7:49 pm
by Moxie26
Peter even though your magneto is working looks like it needs a recharge ...at speed should be between 25 and 30 volts ac. .... When did you last have your coils checked ? ...

Re: Magneto Test

Posted: Wed Jul 26, 2023 7:51 pm
by TWrenn
pspete wrote: ↑
Wed Jul 26, 2023 7:43 pm
Thanks.
So the reason it runs like crap on Mag under load compared to on Bat has nothing to do with the mag...
May very well be the mag...first pull the mag post out and check for lint before panicing about the mag.
Then as Moxie suggested, check the coils too.

Re: Magneto Test

Posted: Wed Jul 26, 2023 8:11 pm
by pspete
Prior to the test I did clean the mag post, and yes it was messy.
I cleaned and gapped the plugs to .025
Cleaned the timer.
Sanded with 400 grit between the points and gapped them to .030
Other than those things have not checked the coils any further as I don't have a coil tester nor know anyone that does, don't even know anybody else that has a T
I'm new to the game, everything I've learned is by reading manual and old forum posts.
Bought the car not running from an estate, so I have made some pretty good progress but far from running well ...

Re: Magneto Test

Posted: Wed Jul 26, 2023 8:21 pm
by Scott_Conger
Pete, your mag output is not terrible and is more than capable of running your car.

Coils can be made to run on battery and still be terrible on MAG - so, now that you know that, lacking test equipment for them, contact one of several guys who advertises coil rebuilding and send off to be checked. Now that you have messed with point gap, they are no longer adjusted (perfectly) if they were in fact even adjusted in the beginning. Adjusting or rebuilding them correctly will make them sing sweetly on both battery AND mag and you will be amazed at how much better things run. For the price of parts and the level of effort involved, paying a pro is a bargain at what they charge.

Welcome to the affliction and congratulations on getting as far as you have :)

Re: Magneto Test

Posted: Wed Jul 26, 2023 8:36 pm
by pspete
Thanks Scott :)
I can indeed feel the affliction/addiction to the T, love a challenge too.
I have no problem paying a pro to rebuild the coils.
All the ads I see are for USA guys and I'm in Canada, not sure about the logistics of shipping back and forth over the border.
Should I just buy a set from Langs?

Re: Magneto Test

Posted: Wed Jul 26, 2023 8:49 pm
by Steve Jelf
For a vertical photo that will only post sideways:
1 Open it;
2 Rotate it 90ΒΊ left or right (it doesn't matter which);
3 Rotate if back to upright;
4 close it.
That always works for me.

Re: Magneto Test

Posted: Wed Jul 26, 2023 9:01 pm
by Moxie26
Pete : .... There are a few guys in Canada that rebuild coils. Check with the Model T chapters in your area....and possibly there's someone in one of those chapters that can recharge your magneto for you.

Re: Magneto Test

Posted: Wed Jul 26, 2023 9:07 pm
by pspete
Will do Rob.
Thank you, that's good to know
Just joined the only chapter that's remotely close the other day, paid my money but haven't heard anything back from them yet.

Re: Magneto Test

Posted: Wed Jul 26, 2023 9:11 pm
by Scott_Conger
I suspect that I know who is doing Lang's coils but am not sure. It really doesn't matter, as Lang's has an outstanding reputation and warrantee and is not likely going to deal with a sub-par vendor (of which there are several very good well known ones and a few lesser known, but good reputation guys, too). I'd opt for 5 rebuilt coils so as to have a spare. Fight any urge to buy unknown coils as some will have bum windings and honestly, avoid the plastic ones regardless of the deal the owner will make. Getting a set of 5 will have them all matched to each other, will be adjusted correctly, have good modern caps and will come with a warrantee.

Bob's advice to find someone in Canada could pay off in spades for future advice and help as well. You're not alone there.

If you had testing apparatus and are handy, I'd suggest you learn to do them yourself as they are more of a filthy job than a difficult job, but there are a few tricks to learn/know, and a bona-fide test setup is mandatory...an excellent future project as you mature in the hobby and have your car in such a state that $$ are available for tools/toys and is not specifically being sucked out of your wallet by the car itself. ;)

good coils, (consider) a rebuilt coilbox for damp weather reliability and a fresh timer of your choice combined with fresh wiring will complete the ignition

Re: Magneto Test

Posted: Wed Jul 26, 2023 9:13 pm
by Moxie26
Well that's a good start.. let us know how you made out

Re: Magneto Test

Posted: Wed Jul 26, 2023 10:37 pm
by pspete
Thank you for your help gentlemen.
I shall keep you posted.

Re: Magneto Test

Posted: Wed Jul 26, 2023 11:07 pm
by Arbs
Pete,

Post some pictures of your project car... we would love to see what you have going on up there.

Re: Magneto Test

Posted: Thu Jul 27, 2023 6:06 pm
by Ron Patterson
Peter
Your 1156 bulb/AC voltmeter Model T magneto test results reflect a puny magneto output.
When I see this type results where the output voltage does not meet or exceed 30 volts at higher RPM I know you need a more comprehensive check
The "Gold Standard" for comprehensive magneto testing that requires no interpretation to determine the "Health" of your magneto is the St Louis Magneto Tesster. It evaluates the magneto results in a different manner and is a go/no go magneto health test.
I suggest find someone who has a St Louis tester, take the readings again and report back as shown in the attyached photo. That wasy we will lnow for sure the health of your Model T magneto.
Ron Patterson

Re: Magneto Test

Posted: Thu Jul 27, 2023 9:53 pm
by mike37 cdn
hi pete i am in ontario i have test equitment but i am one hour north of toronto if it helps mike

Re: Magneto Test

Posted: Thu Jul 27, 2023 10:03 pm
by pspete
Thanks Ron
I have some work to do making good local contacts I guess.
I'll let you know when I get more info.

Re: Magneto Test

Posted: Thu Jul 27, 2023 10:15 pm
by pspete
mike37 cdn wrote: ↑
Thu Jul 27, 2023 9:53 pm
hi pete i am in ontario i have test equitment but i am one hour north of toronto if it helps mike
Thanks Mike, I'm about 2 hours west of Toronto on Lake Erie.
I'll PM you so we can talk about it.

Re: Magneto Test

Posted: Sat Jul 29, 2023 10:28 am
by Moxie26
pspete wrote: ↑
Wed Jul 26, 2023 8:11 pm
Prior to the test I did clean the mag post, and yes it was messy.
I cleaned and gapped the plugs to .025
Cleaned the timer.
Sanded with 400 grit between the points and gapped them to .030
Other than those things have not checked the coils any further as I don't have a coil tester nor know anyone that does, don't even know anybody else that has a T
I'm new to the game, everything I've learned is by reading manual and old forum posts.
Bought the car not running from an estate, so I have made some pretty good progress but far from running well ...
Cleaning contact surface of the points and adjusting the gap on the plugs and the coils physically you did okay. The problem you may have with your coils and most likely would be a failed original internal capacitor and unbalanced tension between the points giving you double sparking and less responsive power. So physically you did great, they just have to be checked electrically for the output. The original internal capacitors really don't last as far as function..... Physical pressure on the coil contacts will give altered electrical response that will change coil output.