Only running on half the cylinders?

[jeff-register]

Everyone has it correct but let me try. The coil has two sets of windings & this motor has two coils. The first set of windings has two ends like a roll of rope. Either end goes to the opposite spark plug. The primary winding is built different too. It has more winds than a 1 cylinder motor in order to make more energy to power the secondary winding as it fires two plugs using either end of the winding. That circuit must be balanced electrically speaking in order to fire both plugs. Measure with your ohm meter (resistance) how much energy it takes to travel all the wraps & to the other end just like any coil. Once the coil see’s a little less resistance it travels to that air gap of the plug. Now at that micro second the coil see’s a connection thru the air gap & releases the rest of it’s stored energy firing the second plug. Now with this motor the second magneto, yes it has two systems it repeats the cycle to fire the third & fourth plugs. Check the second coil the same as the first set. Little known fact if you screw down one plug wire to ground it will double the hot voltage just to fire only one plug. If that coil fits your magneto it will give a much hotter fire for racing or what ever. It would fire a two plugged cylinder for a better burn too. These coils can be mounted outside the magneto & use battery power instead of magnets, then you can run a tube of neon across the top for lighting. I’m thinking WAY out of the box but it would function. Just run a wire from the points & have some FUN!! Te He He!!

[jeff-register]

Did I get that right guys?

[wyo307]

Thank you everyone for the replies! Definitely gives me some things to think about. Jeff I think I am going to keep this one original for now so no neon for me, although that is a neat idea and I would like to see it done.

Mumbles, if I understand your testing procedure correctly you have both sets of two plug leads taped together so that when the mag spins over the spark is jumping between the two leads instead of going down one lead firing one plug then traveling through the block firing the other plug and then completing the circuit back to the coil. Is this correct? I like how visual your method is, you can easily see if it has spark or not. Then if it still doesn’t fire on those two plugs it is probably a bad plug.

I am really learning a lot here and I am loving my zephyr so far. Thanks again for all the help thus far!

[wyo307]

Also on a tangent. Jeff would this same method work for getting a single cylinder motor a much hotter spark if a coil for a twin will fit in the mag plate then just ground out one side? Interesting concept but it makes sense. You have my mind going every which way at the moment thinking of all of the possibilities. One of the many reasons I love playing with these old things.

[Mumbles]

quote Wyo307:

Mumbles, if I understand your testing procedure correctly you have both sets of two plug leads taped together so that when the mag spins over the spark is jumping between the two leads instead of going down one lead firing one plug then traveling through the block firing the other plug and then completing the circuit back to the coil. Is this correct? I like how visual your method is, you can easily see if it has spark or not. Then if it still doesn’t fire on those two plugs it is probably a bad plug.

Exactly. I replaced the points and condensers in this motor with Atom modules and replaced the plug wires while I was at it. The spark was checked before the terminals went on.

The secondary windings in the coil can be checked by undoing the plug wires and connecting an ohm meter to either the two upper or lower plug terminals or if the flywheel is off, connecting to the terminals on the coil. Readings seem to vary but around 8-9 K ohms seems average. The value for your condenser should be 0.10 uF. ’47 and later Zephyrs with slightly different coils have condenser values of 0.20 uF. It seems these magnetos are more sensitive to having the points clean and polished than other mags. Setting the point gap at exactly 0.020" also helps to get a good spark at the plugs which are set at 0.025". If the spark is weak or nonexistent, I’d suspect dirty points or a bad condenser first if the coil checks out OK. A bad plug wire or connection is possible to. Another possibility is the magnets in the flywheel are getting weak and losing their strength.

These coils test OK at over 8,000 ohms.

Atom transistor ignition modules installed replacing the points and condensers.

One Zephyr, ready to go.

[wyo307]

Ok so the other day it finally warmed up enough for me to get out into the shop and play with my zephyr a little bit more. It it amazing how warm 37 degrees can feel after the highs have been in the low 20s for a month and a half. Anyways I checked both coils and they are good so I decided to pull the points and double check them. I think I have found my problem both sets of points were really dirty I am surprised that I actually got it running in the first place now. I also pulled the carb back off and cleaned out the low end mixture passage again since it wouldn’t idle down when I had it running. It looked like there was a little bit of rust or gunk came through the carb that I must have not gotten out when I cleaned the tank. This completely plugged off the low end hole in the back of the carb. So I got that all cleaned out and put back on and now I just need to put the points back in it and gap it again and see if that fixed it. I think it should be good now but I will have to see when it warms up again it cooled back off to a high of 19 today. Thanks again for all of the help.

[Tubs]

A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.

• This reply was modified 6 years, 9 months ago by Tubs.
• This reply was modified 4 years, 5 months ago by Tubs.

[Author]

Posts