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Re: Lambretta advance and retard
Posted: Wed Mar 06, 2013 10:50 am
by Minority
giankx wrote:My mtech did the same too, only retarded from 23 to 17 in the fully retard position.
I initially tought it was due to a bad earth contact, but the unit didn't worked well even on other earth points.
Now i've bought another unit with 2 earth wires. Hope it works!
I have a bgm stator with a Beedspeed midweight flywheel and blue Ducati CDI.
That's three of us with the same symptom. My unit has two earth wires and I have earthed them to seperate positions, one to the magflange/cowling bolt and one to the frame (my general earthing point and where the CDi and regulator are earthed to).
Re: Lambretta advance and retard
Posted: Tue Mar 12, 2013 4:17 pm
by Bren
Wonder if we have been unlucky enough to simply have faulty units! ?
Re: Lambretta advance and retard
Posted: Tue Mar 12, 2013 6:45 pm
by Adam_Winstone
Not exactly why you buy such a unit but the limited advance/retard is in some ways a vary good thing as too much of a range means that you throttle off to cruise and the ignition retards back to a point that the motor starts to overheat. Lots of people with temp gauges on bikes with auto advance retard ignitions have found that their bikes need to be revved hard to run cool! Problem with this is that too much of a range means that you re-set the stator so that the low rev advance is less, then find that a wide range means it retards too far at higher rev, losing you power there too! As such, a wide range can cause more harm than good
That said, that's not the point of buying one of these units that has different maps to choose from.
Adam
Edit: Soz, the other thing that I meant to add to that was that many people are looking to fit longer gearing (higher ratio) to give a more relaxed cruising speed. With these advance/retard ignitions, low revs = greater advance (or less retard) and that puts your motor back into the hot zone. Having too much of a range of retard really can cause you issues unless unless you are riding everywhere at maximum revs

(settings dependent).
Re: Lambretta advance and retard
Posted: Tue Mar 12, 2013 8:10 pm
by drunkmunkey6969
I like to set them up on the lower settings, usually ticking over at 19 degrees and moving back to circa 14/15 on fast road bikes. Keeps the heat down, but maintains power without extending over rev and flattening the curve too much. Each bike is different, but that's a common result.
Re: Lambretta advance and retard
Posted: Wed Mar 13, 2013 10:20 am
by nelson pk
drunkmunkey6969 wrote:I like to set them up on the lower settings, usually ticking over at 19 degrees and moving back to circa 14/15 on fast road bikes. Keeps the heat down, but maintains power without extending over rev and flattening the curve too much. Each bike is different, but that's a common result.
100% agree. The best way to use them in my opinion.
Re: Lambretta advance and retard
Posted: Wed Mar 13, 2013 1:32 pm
by stokky
When I got my M Tech from Martin at Chis, asked him best start point for a tuned bike now not 100% sure, but 95% sure he said,
set to 19% and set MTech unit to B setting
Re: Lambretta advance and retard
Posted: Wed Mar 13, 2013 1:59 pm
by fishi