At low revs those plugs should look a lot darker than that because the plug tips are not hot enough to burn clean. CDI/Igniters rarely miss like that but it's possible that yours is bad. Did you already swap that out? NO I HAVEN'T DONE THAT YET.IT'S ON MY LIST TO DO THE NEXT CHANCE I GET. Have you tried new plug caps and cutting 1/4" off the end of the HT lead? MY ORIGINAL COILS HAD THE WIRES AND CAPS REPLACED.NO CHANGE SO I TRIED A DIFFERENT SET.STILL NO CHANGE.Does it always stutter and stumble the same at low revs or is it sometimes OK and sometimes not? ie is it consistent or sporadic?IT IS RANDOM AND SPORADIC.IT SEEMS TO HAPPEN MORE OFTEN WHEN THE BIKE IS HOT AND UNDER A LOAD,SUCH AS PULLING A HILL AT LOW REVS OR PULLING UP A HILL FROM A STOP.You mention that adding and advancer shifted the revs at which it occurs/stops. That's odd, but may point to poor combustion at those revs and lighting the fire earlier seems to improve things. It would be very useful if you could run it with a timing (strobe) light to see that it's advancing properly.I'LL SEE IF MY LOCAL AUTO PARTS SHACK HAS ONE FOR RENT/BORROW.I'LL GET A VIDI could kick my ass for selling my big tool box and all my tools when the shop closed where I was working.I had bills to pay tho and job to use the tools at.
My timing light was less than 50 bucks from Sears, so I searched and found this one. http://www.sears.com/shc/s/p_10153_12605_SPM5125846801P?blockNo=4&blockType=G4&prdNo=4&i_cntr=1319213110272High load, low rpm sounds like jetting or a weak ignition but they are usually good at low revs and drop off as revs rise. Just for giggles, try it with pilot jets one size smaller/larger just to see what happens. Or try the fuel/float level up/down by 1mm.
My multimeter is fooked. It will test voltage but not resistance.Wish I had my old fluke back.Here's the charging system break down.Voltage at batteryengine off 12.8idle 1200 rpm 14.183000 rpm 13.485000 rpm 13.49Battery drain test came in at 0.60 ma.Sevice limit is 1.5 ma.Stator voltage varied between 85 and 89.Service minimum is 75 volts.I still have to pull the tank and check voltage at the ignition coils.
Hate to say it but those figures tell me your R/R ain't working right. They're similar to what mine shows and it's a dud, voltage should be increasing up to 14. something at 5K RPM, not start at 14. something and drop... Could be just connections rather than a faulty R/R, but it's definitely not right... might also be unrelated to your issue...
Cool... and yes that do use dodgy fasteners! They also supply dodgy R/R's... I've just wired up a cheap Taiwanese copy of a good Honda R/R for mine. The Honda ones are a bit more robust and have a sixth wire for a sense wire so they don't over charge or under charge. I got the cheapy because it was new, cheap, and I could get it relatively quickly.