V50 II Ignition timing

[Exmembers]

I have been unavailable all weekend and I see that a lot of very interesting stuff has arrived on this thread in the meantime. Very interested to see the RiTA circuit diagram, I have never had any experience of one of these and it turns out that all my preconceptions were wrong - well, that’s how it goes. Having had a closer look at the pickups on the Guzzi V50, they also have coils wound on a magnetic pole piece with a rotating steel “lump” on the crankshaft. Presumably this also produces a wasted spark, but it has the advantage that it’s impossible to set the timing 360 crank degrees out, as so many of us have managed to achieve with cam-mounted pickups! Having said that, due to its position etc, it’s still a pig to adjust!

The Morini differs in that it has a rotating magnet and a pickup coil for each cylinder, wound on a laminated steel core. The box of tricks also differs in that it is a SCR-based capacitor discharge circuit. The pulse from the pickup triggers the SCR directly, but has a potential divider, just two resistors to alter the trigger point by changing one resistor, thereby changing the advance range for different models. In practice it makes no difference that I can detect! Once again, these items are 40 years old and are developing some reliability issues. In good condition though, they perform very well. If anyone is interested in the circuit diagram, let me know and I’ll post it here.

Well my conclusion is that I am not going to attempt to modify a Boyer system, though I think it could be fairly easily done. I see no advantage in using old units which have been kicking around my garage, I don’t see why they should be much more dependable than the existing Bosch units. And I’m not going to buy new Boyer boxes. This leaves me two options. Either I’ll live with the Bosch system, warts and all, but pick up a spare box to carry with me (cheap option). Or I’ll bite the bullet and go for one of the modern German systems. Undecided at present!

Many thanks to all for the interesting contributions to this thread!

Joe.

[Simmoto]

@penman

I.

I have found two after-market electronic systems on the internet from Sachse and “Silent Hektik” - both located in Germany. Both look good and both are eye-wateringly expensive. They both come with multiple advance curves, switchable and one (Silent Hektik I think) is programmable. In both cases it should be possible to select a curve which is a big improvement on the original Bosch system.

Standard Sachse curves offer an improvement,IMO yes. See other post for elaboration

Another consideration is that apart from any shortcomings in the advance curve, the Bosch system is almost 40 years old. I’m not sure that I’d trust it for touring abroad unless I was carrying a spare. Spares do appear on ebay, but at silly prices for a second hand bit of 40 year old electronics!

Bosch pick ups seem to be the weak spot, or at least the heat proof insulation breaks down near the pick ups. Otherwise they do seem reliable. Lots of spare boxes around, not many decent pick ups although reconditioning is possible. Certainly Sachse is well made and plumbs in easily. It uses standard coils (I think the Hektick uses its own?) - maybe a plus or a minus - easy to replace standard small blocks anyway

Cheers

[SCMGuzzi]

Hi,
I do not use Silent Hektik’s own coils. I bought a pair of coils from Gutsibits, (from memory), with the correct ohm rating. Although they recommend their own coils the small print is in the installation instructions.
http://www.silent-hektik.de/E_MG_PB5FH_39.pdf
I bought a kit without the coils, much better price.
Steve.