Ignition Coils.

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Hugh
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Ignition Coils.

Post by Hugh »

Greetings brains trust,

The rebuild of the Commando has been completed and it fired up first kick :D
IMG_20210828_104054.jpg
IMG_20210828_104054.jpg (266.81 KiB) Viewed 1803 times
However on road test at first the bike ran really smooth but as soon as I opened it up it accelerated to around 3000 rpm and then it simply shut off :evil: no misfire nor splutter - just off :twisted:

Rechecked all the wiring, original and replaced and no fault found. Initially I suspected the RITA as there is only the faintest of spark, but when the coils were bench examined, resistance seems equal and within spec, replaced HT lead with new copper lead and cap but still no spark of any value.

So I think that I shall retire the coils, 46 years old, but possibly upgrade. This is where you come in, does anybody have experience of Tri-Spark coils, they are 50% dearer than the original Lucas but are they worth it :?:

TTFN

Hugh.
Richard Simpson Mark II
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Re: Ignition Coils.

Post by Richard Simpson Mark II »

Dunno, but that's a nice-looking bike.

Are the front brakes as bad as I remember?
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Paul_C
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Re: Ignition Coils.

Post by Paul_C »

Hi Hugh.
I recently fitted Dyna coils to my old Guzzi and they seem to be doing the job well enough.
All the best, see you on the green roads again one day soon perhaps?
Paul
Just along for the ride.
Husqvarna 901 Norden. Husqvarna 701 Enduro. Moto Guzzi LeMans II.
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chunky butt
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Re: Ignition Coils.

Post by chunky butt »

Hugh wrote: Mon Sep 27, 2021 8:33 pm Greetings brains trust,

The rebuild of the Commando has been completed and it fired up first kick :D

IMG_20210828_104054.jpg

However on road test at first the bike ran really smooth but as soon as I opened it up it accelerated to around 3000 rpm and then it simply shut off :evil: no misfire nor splutter - just off :twisted:

Rechecked all the wiring, original and replaced and no fault found. Initially I suspected the RITA as there is only the faintest of spark, but when the coils were bench examined, resistance seems equal and within spec, replaced HT lead with new copper lead and cap but still no spark of any value.

So I think that I shall retire the coils, 46 years old, but possibly upgrade. This is where you come in, does anybody have experience of Tri-Spark coils, they are 50% dearer than the original Lucas but are they worth it :?:

TTFN

Hugh.

That is one nice looking bike ;)
Jak*
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Re: Ignition Coils.

Post by Jak* »

The best coils I have used on my Guzzi are Landrover ones, although they are a bit thicker than the normal ones. Cheap as well.
It does not sound like the coils are the fault, usually when they go they tend to be fine when cold and then start misfiring. It does sound more like the electronic ignition or possible fuel, although then it would splutter rather than cutting out.
I once had a fault on my Triumph Tiger 750, when it got to about 70 on the speedo it would cut out. It had been running fine for ages and the fault started sometime in the new year, so I thought it might be cold related. I would stop, check the fuel and turn the bike on and off with a spare plug put in the ignition lead, there was always a spark. This went on for about a month, then I noticed that the new key ring my brother had bought me for Christmas would catch in the wind at about seventy, with it being a side mounted ignition switch it was just enough to turn the bike off.
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Hugh
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Re: Ignition Coils.

Post by Hugh »

Greetings,

Richard, the brakes are standard except for stainless pistons which were fitted back in about 1977, it is possible to fit an alternative master cylinder which looks the same but has a different bore so alters the ratio. I like to frighten myself :lol:

Jak, I have tried moving the ignition key slightly to replicate your unusual fault but to no effect. Waggling the looms makes no difference, nor does fitting a 'slave' lead direct from the battery to the RITA.

I had thought about the RITA simply because of its age but all the readings I get are constant.

Paul I shall consider the Dyna coils depending upon feedback. I am still chasing worms on the Serow and Pampera around the Peak District but I fancied chasing hedgehogs on the tarmac with the Norton for a change.

I know a Alan at M&W Motorcycles, Hyde, and they used to have an old Honda coil tester so I will get in touch with him later in the day.

Thanks for your input so far, I will let you know how I get on.

TTFN

Hugh.
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Re: Ignition Coils.

Post by Paul_C »

Ok Hugh. I always happy to get out on my old Guzzi too.
Just along for the ride.
Husqvarna 901 Norden. Husqvarna 701 Enduro. Moto Guzzi LeMans II.
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Re: Ignition Coils.

Post by bill_qaz »

Hugh, have you tried just manually triggering the coils with it just connected to a battery to see how good the spark is?
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Hugh
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Re: Ignition Coils.

Post by Hugh »

Greetings Bill,

Thank you for your suggestion, yes I have. I disconnected the coils from the rest of the wiring, made a copper ht lead and cap, used a dedicated live and earth with a fully charged battery but still only the very faintest of a spark.

Alan is on holiday so I think that I shall just have to invest in new coils and see where that leads :roll:

TTFN

Hugh.
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Re: Ignition Coils.

Post by bill_qaz »

Hugh wrote: Tue Sep 28, 2021 6:40 pm Greetings Bill,

Thank you for your suggestion, yes I have. I disconnected the coils from the rest of the wiring, made a copper ht lead and cap, used a dedicated live and earth with a fully charged battery but still only the very faintest of a spark.

Alan is on holiday so I think that I shall just have to invest in new coils and see where that leads :roll:

TTFN

Hugh.
It's got to be weak coil then, as you have eliminated outside influence , I assume the motor has a good ground or did you earth plug separately during test.
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