Lucas Rita Amplifiers - Differences??

I’ve got several different Rita amplifiers and wondered if some are more suited to my T3 than others.
I have an AB11 4270B with yellow dot
an AB11 48022
an AB11 48022B
and the one fitted to my T3 when I bought her which is an AB5
Does anyone know the ins and outs of these?Normski2012-12-06 14:07:41

You will find all the information available here.

Hi Brian,
I’ve had a look through the website you’ve put a link to already but I can’t see much information about the different amplifiers and their suitability for my T3

i.e. Yellow panel - Bistable amplifier for some total loss battery applications and Triumph and Ducati twins, doesn’t tell me whether that amplifier is suitable for the T3
All the amplifiers work when fitted to the bike I’m just worried about incorrect advance etc.Normski2012-12-06 17:36:37

Well I know no more than you. But if you look through the wiring diagrams you will see that the bistable model runs two 12 volt coils in parallel, the remainder run two 6 volt coils in series. The AB5 has an external ballast resistor, so cannot bedirectly swapped with the AB11 which has different wiring.Other than that, there may be differences in advance curve for different bikes.

Thanks Brian,
The info I’d like may not be out there but there is a chance someone knows the different characteristics of the amplifiers and can explain how they would suit or not as the case could be. I only want one fitted and one to keep as spare for touring and would like to let others go to a good home, before I do that I need to know which is best to keep.

There’s A. O. Services, in Norfolk, advertises in Gambalunga, repairs and services Ritas among other stuff. That’s where I would try. is probably the best person to speak to.

If I remember rightly that all depends on the profile of the rotor, as you’ve said already I also think any amplifer should work.

MOTO GUZZIV35, V50III, V65 (points models - SEE NOTES)
LE MANS 1, 2 LR125
LE MANS 3, 4, 5 LR141
Motoplat in distributor LR144
T3 LR124

Have you looked here it does list the different amplifier part numbers-bikes guzzibear2013-01-20 18:49:27

I think they are kit numbers, not amplifier numbers. (?) I only know of 3 distinct amplifer types including the Moira which I know nothing about. However of the 2 preceding types I’ve traced the circuits of both and they’re both identical in basic function. AB5 or AB11 whatever were used in lots of different kits for all the various bikes. The circuit is so simple no way can it include any additional timing alteration function. There are only 3 transistors, all dedicated to how to get a nice fat spark from a weedy little input signal. It does however have rev limiting. If a bit crudely, ingenious nevertheless. HTH