Regulator Rectifer Question

Can the rec cause ignition/timing/firing issues on our bikes?

Seems pretty unlikely.

Simply unplug it and try. Your bike will run without it long enough to perform the test.

The only way the RR will cause running issues is if it has died and the system voltage is getting to low to make good spark. It is a simple test to check the voltage across the battery with the bike running at above 2000 rpm, it should be about 14V.

I had an ATV in the shop last fall that would fall on its face, buck and backfire if you tried to accelerate. Only happened after it warmed up.

Checking with a timing light it was obviously dropping spark. Turns out the R/R was letting the voltage come up above 17V which caused the ignition module to act up. Voltage wouldn't come up until the battery recharged from starting the machine.

It took awhile to sort out because the service manual refers to the ignition module as a "CDI", and CDIs are isolated from the electrical system. There were no test procedures for the module so I started going through the electrical diagram to figure out what I could test. That's how I discovered it was connected to the electrical system and either a TCI or computerized module. That led me down the path to eventually finding the over voltage.

Your 2nd gen has a computerized ignition module. I can see where it might be susceptible to over voltage or noise. Unplugging the regulator/rectifier will eliminate any of that. This presumes the battery is fully charged and in good enough condition to run the motorcycle for a few minutes.

BUT - a failing ignition won't make white spark plugs. They'd either be normal color or wet with fuel. Your spark plugs are screaming fuel/air.

Yep..thats not it