OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions on Other Engines SB 35

Hi All,

What is a modern alternative for the Magister on the SB 35 Rotary,using the existing engine/magneto setup.

My second magi is dead....well giving off a very weak yellow with all other parts checked set and replaced.

What can be done to Boost voltage either by tapping back into the primary system or utilizing the existing Magi housing?

Cond value is 0.27mfd 500v but what about the secondry coil? Its tiny

Any ideas?

Would it be possible to find a conventional coil that will fit, and just go to the conventional flywheel magneto setup?
As was fitted to the later models, I believe. An aftermarket trigger module would work with that, to replace the contact points/condenser, if required.

There isn't enough information available now to build a replacement Magister unit AFAIK.
Although I have just found some useful stuff in the patent literature, which I will put up on the Magister mega-thread in the Tech Talk forum shortly.

Its running a conventional coil/magneto now,just on a smaller scale. The earlier 35 ran a std size coil assy,but thats as hard to get as a magi. Also I cannot put a std as its a shallow flywheel and no recess on the plate for a larger coil,as I have a wipac from a lauson very similar,but just wont fit.

Theres enough info on it,I know them well enough,just no parts. I can rebuild one,but elec parts like this and from this period would be impossible.

Ive actually stripped a magister and its a fairly simple set up and solid state...but parts:(

I want a small external coil to use in conjunction with the empty magi shell or remotely hidden and dummy the magi for asthetics.

I think I may have found a solution in any case,ill see what comes up when I speak to my elecs mate monday...

Cheers.

Well, not quite, I believe. A conventional small engine magneto setup has a two-winding coil, so it acts as both generator and transformer. The Magister design uses two separate coils, the feed [single winding] and transformer [two-winding] coils, so it separates those functions. And it uses the discharge of a condenser to generate the current pulse for the spark, rather than energy stored in the coil's magnetic field. That's why the Magister spark occurs when the points close, not when they open as with the conventional setup.
Pity your mounting plate doesn't have that cutout. By the look of the pics of Blumbly's unit, some of them did. A flywheel swap would still be necessary, of course.
Yes, there are only three components in one. Rectifier diode, condenser and transformer coil. The first two are too easy; but the coil...
Yup, but you still need the rectifier diode and condenser, for the system to work as designed. Something similar to a coil from a car 'coil on plug' ignition system is what's required, but AFAIK they are all designed to run with 12V feed. Whereas a magneto runs ~200-300V through the primary winding. So the turns ratio required is different.

Hold on until I can get that patent info up - it has details on primary circuit voltage, and the windings of both the feed and transformer coils, in the original Magister design.

Yes thats correct the coil at the mag is the primary and runs down to the mag where the secondry trans core and capacitor are connected then on to the ht lead and plug. I was hoping to switch a coil assy onto the current coil mount as the early victa is recessed back and may just make the gap i require. Then I can run the std condenser points assy as normal. This is one option.

Yeah the first two parts are easy...but so to maybe the secondry trans coil as there appears to be a few small versions available...

Coil for a car will work,ive seen it done...values are all messed up and its kinda huge so not even thinking that path,and as you say they are 12v start up and 8v Running.



Ive got the capacitor value at 500 v 0.27 mfd and a schematic of the wiring and component paths.

So if you can come up with the Remaining values or patent image id be most appreciative.

Thanks.....

https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Nuis nber=37014

Just curious about something in the Wipac Magister feed.

A, The diagram for the magister appears incorrect,was this made or is it the original? Its shiwing a std magneto coil assy with primary and secondry and another secondry? This doesnt seem accurate am i missing something?

B, Deejays Magister for blumbly couldnt possibly work as there Is no Primary wire going into the magister! The wire is in the loom but doesnt enter the unit.

The green wire from the primary magneto/coil is supposed to enter the magister next to the purple and attaches to the secondry trans coil....

If its as mine are then it cannot work...

I can't make your feed work, Blue. Were you talking about this circuit diagram?


The circuit can be seen in a published magazine article, referred to in this thread:
https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=37014&page=3

I agree that in the picture of the Magister Deejay obtained for blumbly, one of the three wires seems to end somewhere inside the three wire harness. A trauma sometime during its long life, perhaps.

Yes grumps...that diagram. No its correct what confused me was the primary and secondry coil section...but if you look at the primary trans coil inside the magister is in two winds,one inner one outer....so its all good....when I looked at it I firstly thought it was the magneto coil...all good:)

Blumblys coil was meant to have been tested and operational by my understanding.

The green wire is the feed from the primary magneto coil to the rectifier and loops back into the switch then into the primary of the trans coil....So it can never work!

Ok its fairly simple in the flesh I just need the parts.

my aim is to make a module like the magi but smaller and mount it under the fly plate unseen. The coil wire will leave there and pass through a dummy hole in the real magister and the wires will hook up as normal but dead ended under the fly wheel.

essentialy it will look as if nothing has changed.

just need the parts and the other two values for the rectifier and trans coil...hopefully my electronics mate will be able to work it out via the capacitor value. Or compared with a std victa coils rating....

Ill just be patient and see what gadge can come up with

cheers guys...

Puts it aside and plays with my new aquisition ....Villiers Villager mmmmmmm

Gadge has now supplied most of the component details, including the coil winding data both for the feed coil (inside the flywheel) and the transformer, or HT, coil (inside the earphone unit). I'd have thought it would be both more authentic and more practical to retain the original design, rather than have an HT wire a yard long, passing through a fake earphone unit, now that the component details are available. Remember, Phillips used to make replacement earphone units for the aftermarket. Their version was extraordinarily ugly, but shows it can be done provided you have access to the patent information (as we now do, thanks to Gadge).

What I actually had in mind was the 'pencil coils', used one per plug on some late model cars and motorcycles. These look like a very long spark plug cap. Not a full size car coil, either from a coil pack or distributor ignition!

The actual coil in these is very compact. But the car units are still wound for 12V input, not the 200V+ the Magister feed coil puts out. Apparently the motorcycle pencil units are wound for ~500V input from a CDI, but that is on the other side of the wrong turns ratio for the Magister system.

Perhaps I didnt write it correctly....Since ive been an automotive mechanic for over 25 years I have access to the lastest technology and its the first place I looked for an alternative before I fully researched its actuall function and found it to differ greatly,so I understood your meaning! But its not an option,hence my prase,Im not going down this path" as its just not compatible...Ive given the whole unit including primary coil and points and a diagram to my elec mate and he will sort out the best option.

I have found some evidence of early suzuki bikes using a similar system;but again id rather just find the components to fit back in the original unit if possible....