1981 carb Wont rev out. intermittently...

razmo99 wrote: I know for a fact that the Timing Rotor is a bit iffy, 3/4 are on the F mark but 1/6,2/5 are before F by a bit. Really want to fix this but cannot source a new rotor. Kinda certain that this wouldn't cause it to drop cylinders just make it run rough, have less power and a bit retarded .

What are your concerns about the rotor?? I seem to remember something posted in the past but.....

The window of the rotor passes by all 3 pick up coils and triggers the spark. If the window is the same for all then it's not the rotor.The 1981 model (your bike) has electronic timing advance which is part of the ignitor. If the timing is spot on for 1 coil and off for the other 2, then I would think the ignitor is the problem.

You couldn't have measured the applied voltage to the pick up coils as per page 327 of the manual. 8 volts is not the spec. 5.6 - 6.2 V across the white and gray lead.

Also note that the dwell for the coils is also controlled/ altered by the ignitor and maybe that part of the circuitry is messing with the ignition coil outputs.

The concern is that the alignment Grooves on the rotor and starter clutch is a bit chewed from it chattering as it was lose, meaning it has slop. Hence it may be out of alignment when tightened either a bit advanced or retarded...

Cylinder 1&6 ,2,5 are intermittently sparking and 3,4 are spot on.

What I got done this arvo;

All Coils are getting the same Voltage and have the same resistance.
Rechecked applied voltage to the Pickups its 5.4-5.6v, sorry for incorrect info before.
The continuity of the pickups was checked when hot and they are in spec.

At this point its either the igniter, or the Timing being slightly off is screwing with the igniter making it malfunction.

Thoughts?

Pretty sure this will all boil down to the pulser coils.

You've measured the applied voltage and it's fine -good.
You've measured the continuity -good.
You had a wobbling pulser coil rotor -bad.

so let's talk about those pulser coils.
They have 2 parts. I suspect the outer part is the coil itself meaning the 2 wires are attached to that outer lump and your testing has ensured that they are intact -good

The inner lump is a magnet. when the rotor windows pass through the magnet and coil, the window allows the magnet to act on the coil and trigger a "pulse" so what's critical here is the magnet affects the coil. If the air gap between the magnet and coil is out then it's possible the magnetic signal is not affecting the coil to generate a positive pulse. The wobbling rotor may have knocked a couple of the pulser coils and "altered" that air gap.
I would be checking that air gap. You have one good "sparking" ignition coil so you know that pulser coil associated with that ignition coil is good so use the air gap in that pulser coil as a reference and check the air gaps in the other 2 pulser coils against that "spec".
I'd also check the magnet strength in the pulser coils. Use a small screwdriver and check the magnet strengths (touch the pulser coil magnet and pull the screwdriver back off) and see if you have dead magnets on the 2 pulser coils in question.

I'm shooting in the dark here. I understand the theory. I believe all your troubles are related to that wobbling rotor and what may have happened because it was wobbling.

Did you check the primary side resistance of the ignition coils? If you have the original resistor (white ceramic block) in place, then your primary resistance should be ca. 2.7 ohms combined. (resistor block + Coil)
If the coils have been replaced and the resistor block removed, then the primary ohm rating must be higher than 2.5. If it is lower, the output transistors will be damaged.
The power supply of the Hall sensors comes from the input card of the igniter.
Output transistors are located on the other card of the igniter.
The Hall sensors are mounted into the black plastic housing, magnet on one side, the sensor on the other side.