Wildguzzi.com
General Category => General Discussion => Topic started by: baloo on June 28, 2025, 11:16:09 AM
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This is a 1989 MG Mille GT, about 40K miles.
What are the latest recommendations for electronic ignition conversions (and coils) for my bike?
Is it still the Dyna-III?
BTW, bike has been sitting about 3 years - just got it restarted, and lotsa backfire at 5000 rpm. Might be the gas - have not retested it since draining and adding new gas, sooooo, fingers crossed it has magically cured itself, right?
Thanks.
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Backfire or misfire?
5000 rpm under load or in neutral?
I wouldn't jump to any conclusions until you purge the old gas.
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Have you points? If so then Dyna and it'll work with any coils the correct rate. If you have Guzzi's electro dizzy from then, you have to get a Marelli then Dyna.
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That model normally came from the factory with a motoplatt electronic ignition.
the sachs zdg is a good replacement for that and comes in various styles of placement
https://www.elektronik-sachse.de/shopsystem-3/en/digital-ignition-zdg-3-23-for-moto-guzzi-with-bosch-alternator.html
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Have you points? If so then Dyna and it'll work with any coils the correct rate. If you have Guzzi's electro dizzy from then, you have to get a Bosch then Dyna.
That model normally came from the factory with a motoplatt electronic ignition.
the sachs zdg is a good replacement for that and comes in various styles of placement
https://www.elektronik-sachse.de/shopsystem-3/en/digital-ignition-zdg-3-23-for-moto-guzzi-with-bosch-alternator.html
My '89 Mille GT (bought new) had points and a Saprisa charging system, same with my '90 Cal III C.I.
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Fixed it for ya Charlie, I'm just used to saying Bosch instead of Marelli(getting old).
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Thanks to all!!
I was not getting instant notifications via email, so thought no one had replied until I just checked back at this forum -- my bad.
I changed out the gas -- but now dead dead dead battery -- one on order from Amazon (going with Lithium).
Will check type of IGN on the bike. I am not on top of/intimate with this bike like my other vehicles.
Again, bad me, but this time for neglecting the bike for so many years! Damn, how time has flown.
(In the meantime, have been preoccupied with old cars (58 MGA coupe, 51 Hudson Super 6, 72 CItroen SM).
EVERYTHING needs attention, and I have genuinely reached the "elderly" stage where my cognition and energy are fading. I know lotsa youse guys are older than me (75), but everyone has different rates of degeneration, right?
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Backfire or misfire?
5000 rpm under load or in neutral?
I wouldn't jump to any conclusions until you purge the old gas.
Backfire, and in neutral at 5K rpm
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That model normally came from the factory with a motoplatt electronic ignition.
the sachs zdg is a good replacement for that and comes in various styles of placement
https://www.elektronik-sachse.de/shopsystem-3/en/digital-ignition-zdg-3-23-for-moto-guzzi-with-bosch-alternator.html
Yikes -- with shipping, that's about 475 EUros which is well over $500 USD.
Hmmmm, bike's not worth $5000 USD, so 10% of the bike, which has not been ridden over 100 miles since my purchase in 2021, and not likely to get ridden too much in the future (wife refuses to ride).
Might have to rethink this idea, unless there are used e-IGN units (of which I would be wary when it comes to used electronics).
I'm sure youse guyz will have suggestions and opinions. I'm open to comments on this.
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Lithium battery isn't such a good idea, IMO. The stock charging system likely won't have the charging output it needs. An AGM or even SLA would have been better.
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Lithium battery isn't such a good idea, IMO. The stock charging system likely won't have the charging output it needs. An AGM or even SLA would have been better.
"Won't have the charging output it needs"... Do you mean not enough, or is it because Li batteries need some sort of special charging sequence? I have noticed that my battery chargers have a special selection for Li batteries.
Is that why?
I had thought that Li batteries do not discharge like flooded and AGM batteries do when just sitting unused.
No probs, I will cancel the Li and get an AGM. Cheaper anyway.
...but interested in the explanation.
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I just querried AI about using a Li battery in an old motorcycle, and yep, you right -- potential problems.
Here's what AI said:
"Older motorcycles (pre-1990s) often use permanent magnet alternators with simple shunt regulators, which:
May overcharge if the voltage regulator consistently pushes >14.6V.
May undercharge if voltage rarely exceeds 13.5V.
Lithium batteries prefer charging voltages of 13.8–14.6V for full and safe charging."