Hi Garry,
Okay, so more dumb questions from me:
I had an RGS for many years myself, and since then, I have my SFC.
When I syncronise the carburettors, I use a small gastank on a stand, next to the bike. It contains ½ a Liter of fuel. This way all wires are exposed, so I can work on them.
With wire shaking, I meant the wires that are originally on the RGS, leading from under the seat, to the coil pack. Have you replaced those when you installed the Sachse system? Or do you still have those in place? I would look into those. An old wore can easily break inside the sheath, not being visible, and once under heat/load/vibrations/more Voltage demand (for some wires, not all of course), it gets a very bad or broken connection. So when you move them, one by one, or as a bunch, you Ohm them at the same time (with beep on). Get an extra pair of hands.
Also, some wires break exactly where they are crimped to a thin metal connector leg, and then stuffed inside a bigger hard plastic square connector, such as on Laverda RGS/SFC/any model.
a/ What plugs are you running? Brand and heat number?
b/ Which cylinder is falling out? Flip components if possible between cylinders.
c/ just another thought: On some RGS bikes, or late Jota 120, the small round engine cover that covers the ignition pickups (on original bikes or one that still retains those pickups, like my own DMC system on my SFC), there is simply missing a bit of the casting, so that there is access for water and dirt to enter via the top bolt for that little cover, which must have a bit of casting on it's backside next to the top bolt. I just had an example here in my waters of that problem. That possibly led to the DMC2 optical pickup dying. Unclear, cracked or loose wire connection inside it.
Since I don't know the Sachse system, I would in ANY case look into that too.
d/ Have you had ANY bulbs blowing on you lately?
e/ Did you measure Voltage from the rectifier?
f/ Is it the original rectifier from Nippon Denso?
g/ Is it another rectifier? I run a model built here in Denmark by an unfortunately passed electrician, who built thousands of these for all brands of bikes using Nippon Dense rectifiers, which breaks down (with guarantee) over time. First sign is usually bulbs blowing. But it could show differently.
h/ take off all 3 spark plug caps and measure them for Ohm.
i/ while running the engine at idle, then faster, then faster, move the wires, coil pack, ignition wires (HT).
j/ take off and very carefully inspect the induction rubbers, whether you have them original or changed, do it, and while having one in the hand, press them and look for cracks. When becoming hot, and under load (high revs), they can behave strangely.
k/ please describe with more words, how the cylinder falls out. Does it return immediately to sparking/running when lowered in revs? Or?
l/ What carburettors? What jets, needle and other parts? What setting? And what fuel? When I tried to run modern crap fuel, I got weird behaviour. I emptied it all out, and filled with fresh 100 Octane Shell plus a tiny bit of Castrol valvemaster additive WITH octane riser. Perfect again.
m/ Does your fuel level indicator work or show strange behavior?
n/ Did you Ohm the dead man switch? Did you take that switch block/contact apart and clean it out?
o/ Have you used a genuine electronics contact cleaner such as Contact 60 (the white can with red writing) on EVERY single connector on the bike? Then shake it all again and Ohm it all again. Measure Voltage before and after that to see if there is ANY difference in Voltage. Every single wire.
p/ I don't know the Sachse system. Does the box have a multiconnector you can investigate? If you replaced the box, did you also replace that multiwires leading to and from the box?
q/ sometimes solderings go loose, and shows up when hot, actually especially when vibratingmore/hotter. Inspect any soldering anywhere you can. Sachse box/ instrumentation, ignition switch, all over. I had an ignition switch die on my former RGS. Cracked soldering are sometimes very hard to spot. Resolder-clean with flux, resolder if ANY doubt.
r/ On any pcb, such as inside the instrumentation cluster or on ANY other pcb, for example an ignition box, switch etc, any via-s (tiny cylinders going through the pcb from one side to the other, leading current), can go bad. More so when hot, more voltage, vibrations, coldness etc. Inspect that as well.
s/ Ohm your ignition switch.
t/ And just another dumb question: have you had your carbs apart? Inspected the cables? Inspected the pins/cables that pulls the gas valves (60/2?)?
u/ ANY ground cable can have a lot of green corrosion (on copper) or other corrosion underneath the protection sheath. And it can actually crawl up inside it and reach pretty far. Seen that many times. So off they go, inspect, cut up, inspect, clean, replace, all of them..
Cheers,
Jacques
