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RS1 magneto change rotation

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JD84:
Hi all,

Had to source another mag for the Lister D as the coil went. Managed to pick up one cheep which saved on a coil rewind and it offers a great spark. Problem is its set to anti clockwise rotation... Does anyone know how I would go about changing it to clockwise? Any help would be much appreciated

Many all thanks in advance!

guest23837:
I would have thought it would make a spark no matter which direction it was turned. Wiser heads than mine will clarify this

cobbadog:
The Lucas RS1 and SR1 can be made work in reverse rotation but there is a trick to it. There are a couple of things to try first.

Would it be easier for you to swap the coils over as the steps for reversing rotation are a little bit tricky?

If you want to reverse it you have to understand what the magnetic flux is in your magneto. this is the resistance as you rotate the armature. As the flux gets it its highest point this is where the cam starts to open and to alter the timing on the cam is one of those jobs you need 3 hands for. The cam would need to be loosened and pulled away off the taper it sits on so you can move it to be at the best position for reverse rotation. Once you have found the best flux point you have to hold the armature in that exact spot and then rotate the cam lobe so that the points are just breaking.

My best advise is swap the coils over, simplest fix or go to a magneto bloke and get him to do it or there are books on how to do this on Lucas magnetos or research YouTube.  Let us know what you decide to do.

JD84:
Thanks for the responses, it was very informative, thankyou.

I totally see your point with regards to the simplicity of changing the coils over, and to be honest I didn't think of that.

However, I would like to try the second more fiddly option of cam positioning.

Reason being I can use the new magneto, which is in an overall better condition, less corrosion, better bearings etc. Additionally being able to set it to the best available point of flux would be great and a good skill to learn.

I understand its just as the magnetic field begins to collapse that spark is produced. I have seen some information online but not solely for the this magneto.

Any further help on the stages of the process, disassembly etc along with ideas of cam removal would be much appreciated.

cobbadog:
I just thought of something else and that is you MIGHT need the other ignition plate to be fitted when reversing the rotation s that the cam opens the points from the right direction. Sounds silly I know but it does make a difference I believe.
Another option for you is to swap the coil to the magneto with the right rotation but put the complete workings into the better body, this is a straight forward swap and again easier than altering the cam position.
If going for the cam re-positioning mark it before you move it so that you can put it back if needed. Test the flux on it before moving anything so that you get the feel of what it is you need to find when changing it.
Sorry for my late thoughts

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