Misc: Ignition Best Place for a Coil

Monkeypants

Well Known and Active Forum User
Non-VOC Member
My OZ Rapide has Norton twin coils under the mag cowl. They are mounted to the side-stand casting with a metal bracket and couple of thick O rings. The O rings are stretched over the bracket and coils to hold them in place.
On first inspection it seemed pretty hokey, but it worked fine, so I left it alone. The rubber O rings are twisted in a figure 8 so the coils are truly rubber mounted.
One small nicety is that the coils and wiring stay in place when the mag cowl is removed, no wires to get yanked on when moving the cowl aside. My other Rapide has the coil mounted to the cowl and you have to be a bit careful with that when removing or replacing the cowl.
That Norton twin point twin coil setup went on when the bike lived in Scotland in the 70s.
It's done a lot of miles since, including a decade or two in Australia with a young owner who used it as daily transport then crisscrossed OZ with it for his annual holiday.
The location doesn't seem to be a problem, Ive had it out in every kind of weather.
There is a plastic deflector piece mounted to the bottom side of the sidestand casting.
This runs back six inches or so under the engine.
At some point I recognized this piece to be part of a plastic milk jug!
Its important to change the Orings every 20 years and change the milk jug every quarter century or 100,000 miles, whichever comes first :)

Glen
 
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Dave61

Well Known and Active Forum User
Non-VOC Member
My OZ Rapide has Norton twin coils under the mag cowl. They are mounted to the side-stand casting with a metal bracket and couple of thick O rings. The O rings are stretched over the bracket and coils to hold them in place.
On first inspection it seemed pretty hokey, but it worked fine, so I left it alone. The rubber O rings are twisted in a figure 8 so the coils are truly rubber mounted.
One small nicety is that the coils and wiring stay in place when the mag cowl is removed, no wires to get yanked on when moving the cowl aside. My other Rapide has the coil mounted to the cowl and you have to be a bit careful with that when removing or replacing the cowl.
That Norton twin point twin coil setup went on when the bike lived in Scotland in the 70s.
It's done a lot of miles since, including a decade or two in Australia with a young owner who used it as daily transport then crisscrossed OZ with it for his annual holiday.
The location doesn't seem to be a problem, Ive had it out in every kind of weather.
There is a plastic deflector piece mounted to the bottom side of the sidestand casting.
This runs back six inches or so under the engine.
At some point I recognized this piece to be part of a plastic milk jug!
Its important to change the Orings every 20 years and change the milk jug every quarter century or 100,000 miles, whichever comes first :)

Glen

It's amazing how inventive some people are Glen, love the bit about the plastic milk jug.
I did wonder about the concerns about the vulnerability, after all the original mag lives under the cowl & my coil has fully encapsulated ht leads & I'll be sure to cover the feed wires with rubber boots, though I don't think Wellies will be suitable !
Cheers
Dave
 

BigEd

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VOC Member
VOC Forum Moderator
It's amazing how inventive some people are Glen, love the bit about the plastic milk jug.
I did wonder about the concerns about the vulnerability, after all the original mag lives under the cowl & my coil has fully encapsulated ht leads & I'll be sure to cover the feed wires with rubber boots, though I don't think Wellies will be suitable !
Cheers
Dave
;)
I have a BT-H magneto and the two small coils mounted under the cowl. Never had an ignition problem in 40,000 or so miles riding in all weathers.
It has been known to rain a bit in the UK. Perhaps I'm just lucky.
 

Dave61

Well Known and Active Forum User
Non-VOC Member
This is what I came up with, I used a piece of Stainless pipe I`d been given & cut a wide slot in it to fit the coil.
I`ll see how this goes & can always come up with a MK II or MK III version.
Cheers for all the advice.
Dave
IMG_20190427_144814.jpg
IMG_20190427_144830.jpg
IMG_20190427_145012.jpg
 

Dave61

Well Known and Active Forum User
Non-VOC Member
Dave61, I would worry about the HT leads touching the barrel and head fins in your photos as they could melt through the insulation. It has happened to me in the past.
Simon
Thanks for the warning Simon.
I`d draped the leads out of the way to take the photos so it probably looks worse than it is, hopefully when I`ve got the cover in place I can make sure of the clearance.
If I can keep making progress it won`t be long before I pester you for help in getting it re registered.
Cheers
Dave
 

Oldhaven

Well Known and Active Forum User
VOC Member
You may need to whittle away some of the bracket metal where the mag cover gap meets those brackets. or you may be lucky. I know I did, but that method works well. nice job.
 
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Dave61

Well Known and Active Forum User
Non-VOC Member
You may need to whittle away some metal where the mag cover gap meets those brackets. or you may be lucky. I know I did, but that method works well. nice job.
Thanks for that Ron.
I had tried to fit the tube lengthwise between the Mag & Filter with a Stainless strap round the long mag bolt, it looked good but I couldn`t get the cover to sit right, might have another go, keep forgetting I can pump the bike bench up to get a better view of things, there`s no hope for me !
Cheers
Dave
 

Dave61

Well Known and Active Forum User
Non-VOC Member
Had a rethink as I didn`t like the way the Mag cover was sitting & reverted to my original idea of mounting inline with filter & ignition.
Think it looks neater & cover fits well now.
Cheers
Dave
IMG_20190526_161144.jpg
IMG_20190526_161117.jpg
 

macvette

Well Known and Active Forum User
Non-VOC Member
My OZ Rapide has Norton twin coils under the mag cowl. They are mounted to the side-stand casting with a metal bracket and couple of thick O rings. The O rings are stretched over the bracket and coils to hold them in place.
On first inspection it seemed pretty hokey, but it worked fine, so I left it alone. The rubber O rings are twisted in a figure 8 so the coils are truly rubber mounted.
One small nicety is that the coils and wiring stay in place when the mag cowl is removed, no wires to get yanked on when moving the cowl aside. My other Rapide has the coil mounted to the cowl and you have to be a bit careful with that when removing or replacing the cowl.
That Norton twin point twin coil setup went on when the bike lived in Scotland in the 70s.
It's done a lot of miles since, including a decade or two in Australia with a young owner who used it as daily transport then crisscrossed OZ with it for his annual holiday.
The location doesn't seem to be a problem, Ive had it out in every kind of weather.
There is a plastic deflector piece mounted to the bottom side of the sidestand casting.
This runs back six inches or so under the engine.
At some point I recognized this piece to be part of a plastic milk jug!
Its important to change the Orings every 20 years and change the milk jug every quarter century or 100,000 miles, whichever comes first :)

Glen
Here's my coil set up with BTH CDI system. Two plastic coated pipe clips fixed with small screws and nylock nuts so two 4mm holes in the cowl. Ive been a little generous extending the low tension leads.
This set up allows the cowl to be removed and filter change made easily.
 

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