Lucas ignition testing

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mizike77
860 GT / GTS
Posts: 272
Joined: Sun Jul 06, 2008 9:37 am

Lucas ignition testing

Post by mizike77 »

My 78 GTS has a Lucas system. The bike has been great until yesterday. 70 mph down the highway the ignition cut out. I have all lights and systems, but no spark. All connections look good. How do I go about testing the Lucas system? The bike has Accel wires and coil.
79 Darmah
78 900 GTS
86 F1B
80 SSD
02 Harley FXD
72 H2 750 triple
08 KTM 300XC
there has yet to be a motorcycle line made that is as satisfying to ride, hear and look at as the ducati bevels

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BevHevSteve
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Post by BevHevSteve »

Michael used to be the NA distributor for LR systems, his website is still up, go have a read.. http://eurospares.com/elec.htm
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Ducati/Euro Spares -> https://Store.BevelHeaven.com
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mizike77
860 GT / GTS
Posts: 272
Joined: Sun Jul 06, 2008 9:37 am

Post by mizike77 »

Fantastic, thnak you.
79 Darmah
78 900 GTS
86 F1B
80 SSD
02 Harley FXD
72 H2 750 triple
08 KTM 300XC
there has yet to be a motorcycle line made that is as satisfying to ride, hear and look at as the ducati bevels

User avatar
Geoff
Parallel Twin
Posts: 103
Joined: Mon Jul 26, 2004 11:43 am
Location: London, UK

Post by Geoff »

I don't think Eurospares can help anymore. I've used (from the US and UK) the guy here both for spares and once for testing my unit:

Mistral Engineering
Unit 12 Taylors
Gravel Lane
Chigwell, Essex
England IG7 6DQ
+44 20 8501 2161 voice

He's very helpful. In the end there was nothing wrong with the unit, rather the coil had gone (I was using a dual output green dyna).

The other thing you should watch out for is the voltage; the Rita MUST have at least 12V at the coil and unit to work. Lights will work fine, but not the Rita so watch out and check. Not just at the battery either, do voltage drop tests from the battery to the coil and unit and identify if there are any areas of high resistance dropping volts unecessarily. I ran a direct line from the fuse box to the unit bypassing the switch in the end...
Good luck
Geoff

mizike77
860 GT / GTS
Posts: 272
Joined: Sun Jul 06, 2008 9:37 am

Post by mizike77 »

Hello Geoff, after a few hours of surfing the internet and testing various components on my own, I decided to take the coil off and bring it to my local shop for testing. Sure enough, it was bad. Its a yellow accell supercoil dual output. I ordered a new one up and so far so good. Mike
79 Darmah
78 900 GTS
86 F1B
80 SSD
02 Harley FXD
72 H2 750 triple
08 KTM 300XC
there has yet to be a motorcycle line made that is as satisfying to ride, hear and look at as the ducati bevels

User avatar
Geoff
Parallel Twin
Posts: 103
Joined: Mon Jul 26, 2004 11:43 am
Location: London, UK

Post by Geoff »

Good! What's the resistance of the coil you're using? The green dyna is 3ohm and it's probably to low. After much discussion with Mistral and Dyna I ended up putting a 1.5 ohm (I think) ballast resistor in series with it and it's been fine for starting and running. If the resistance of the coil is too low it will overheat and possibly fail.

Good luck.
Geoff

mizike77
860 GT / GTS
Posts: 272
Joined: Sun Jul 06, 2008 9:37 am

Post by mizike77 »

3 ohm here also. The bike came to me with this setup. I have no idea how old the coil that failed was. If the paperwork I got with the bike is correct, according to mileage the coil would be around 10 years old at the very least.
79 Darmah
78 900 GTS
86 F1B
80 SSD
02 Harley FXD
72 H2 750 triple
08 KTM 300XC
there has yet to be a motorcycle line made that is as satisfying to ride, hear and look at as the ducati bevels

User avatar
Geoff
Parallel Twin
Posts: 103
Joined: Mon Jul 26, 2004 11:43 am
Location: London, UK

Post by Geoff »

still, based on my conversations with Dyna and especially Mistral, I'd recommend chucking either 4.5ohm coil on or a 1.5ohm ballast with a 3phm.

It doesn't harm anything but will almost certainly extend the life of the coil. (I used to think that the lower resistance on the coil the better for spark, but that doesn't appear to be true)

Good luck

Den
Mach 3
Posts: 89
Joined: Fri Apr 09, 2004 6:02 pm
Location: Florida, USA

Post by Den »

Geoff wrote:...still, based on my conversations with Dyna and especially Mistral, I'd recommend chucking either 4.5ohm coil on or a 1.5ohm ballast with a 3ohm.


"...ballast resistors don't have a fixed resistance."

http://www.ducatimeccanica.com/articles/coils.html

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