stator rewind

[LoudenSwain]

Hello, so I am gonna give it a go rewinding my ignition coil. I'm measuring 170 ohms consistently on multiple meters and the bike is hard to start so its time. Also sent the pickup out to be rebuilt so there's some down time. It's for a 500 Sport but I figured might as well post on the 3.5 heading as it pertains to all and the 3.5 gets the most eyes. I've read the moriniclub.nl over and over and used the search button here many times so I'm set on what to do. One question that might seem trivial and I haven't seen it addressed is how perfect/layered do the winding have to be. Does it have to be wound perfectly layered building up even or is it okay to go for neat, tight and tidy. I would suspect the goal is to fill the bobbin up tight trying to attain as close to 300 ohms as possible? Thanks and hope all is well with everyone.

[mbmm350s]

Hi
Go for it!
Unless you have a coil winder it is difficult to count and to be tidy, but for this application it really doesn't matter.
I unwind unknown bobbins and count the turns and rewind the same as i took off,
if its really untidy you might not be able to get as many on as were taken off,
but honestly a freshly rewound coil without all those short circuit turns and layer to layer shorts
is going to be so much better.

Putting on more turns just in case sure means more volts -
but you have to be certain that the components in the system will not be over-stressed.
just put back on what you took off.
If you cant count them off just wind it and don't worry,
i doubt that hand wound will exceed machine wound.

I have designed switched mode power supplies where these things matter.
But for ignition windings you will have no problem.

One thing to take care of is to maintain a consistent tension when winding
to avoid straining the fine wire, so its better to be loose than tight.
If you make a mistake and the wire snags - just scrap it and start again
You will need the proper (solderable enamelled ) wire standard - so get it from here.
https://www.wires.co.uk/acatalog/sx_ec_wire.html

take care of the bobbin as they can be quite fragile
and there is a lot of varnish around.
As its a 500 the copper overvoltage plate is riveted to the stator plate,
and has to be removed so you need to re-rivet it afterwards.

It will work fine! And your leg muscles will reduce through less usage
Cheers
Mark

[MickeyMoto]

Better still, send it to West Country Windings and let them do it. They can check the alternator windings at the same time.

From a weak spark to first kick start!

[Ming]

Hello Louden, I have done it for a Kanguro. It's pretty easy to do, if a bit boring in places. If you look on the Dutch Morini site thee is an article showing how I did it, together with a few improvements on my method. One point to watch (and I think it's caught out a recent poster) - I put the stator back together using screws and bolts, rather than rivets. After some while, one of the screws loosened, came out and caught under the cam belt, causing it to break. This resulted only in shortened push rods (luckily), but needs to be considered.
Here'a a link to it. http://www.motomoriniclub.nl/rewindignitioncoil.html

[LoudenSwain]

Thanks for the responses. I had forgot to ask about the screw and bolt method which seamed suspect when I read it. Thanks for hitting that point Ming. I have already ordered the wires from wires.com.uk mhmm so hopefully they will be here in the next few days. Lately I have had stuff either breeze through customs in NY or sit there literally for months. Worst was a vintage pair of Konis that sat in Jamacia NY for 89 days. Painful to watch the tracking when grinds to a halt. I watched a YouTube video of a guy rewinding a scooter bobbin and he used a gutted ball point pen casing. He ran the wire through it and was able to keep the tension as he wound. Gonna give that a try. I did send West County Windings an inquiry, still not out of the question Mickey. That would be the reasonable thing to do to most. I'll keep you posted with results or if I chicken out.

[jb666]

I'll have to get my coil winder working again!! It was headed for the skip when a friends firm moved premises. Wound a new coil for the Kanguro on it then put it on the shelf - a low one as it is a heavy lump! The only hints I can give is to put a layer of polyester tape around the bobbin before you start winding and then finish the coil with another layer of polyester tape. I then potted mine with Araldite.

John.