rd125 weak/no spark

Just picked up a yamaha rd125 twin and it has no spark. I hate electrical, so this is a learning experience for sure. Bike has great compression and is now getting fuel after i cleaned out the carbs. Only thing holding it back is spark. I have a manual for it and i tested the coils. Primary coil is supposed to be 4 ohms + - 10%. Secondary coil is supposed to be 11k ohms + - 20%. Left coil primary was 4.3. Secondary was 8.35 through the wire with no plug boot and 16.88 with a plug boot. Right coil primary was 4.2ohms and secondary was 8.16 through the wire, and couldn't get a reading with the plug boot on.

Plugs look to be brand new. Neither of them will spark. So i pulled a known good plug out of my g3 and can get each coil to make almost invisible sparks. Any ideas? condensers maybe? There was a test for condensers in the manual, but it required a special machine supposedly, and i find it hard to believe that both would be bad. Continuity test on each set of points works when they are closed, but could weak spark be caused by dirty or way out of adjustment points? Any and all help would be GREATLY appreciated. Bike is in very good shape and i am anxious to ride it.

Yes, dirty and/or out of adjustment points can cause weak spark. You can clean the points up with some emery cloth or some very fine sandpaper. And then gap them to specs. If you don't have feeler gauges, set the gap to a business card. It'll be close enough to run.

points looked clean, but i cleaned them anyway. replaced coil wires, and set point gap and ignition timing to the best of my ability with the limited tools i have. (<--READ probably wrong) But i now have what i'd consider healthy spark. Bike starts up and idles. wont go much higher than idle without dying. Didn't seem to be running right. Upon closer inspection (feeling each exhaust pipe after running) i found out only the left side cylinder is firing.

Now the weird part... if i pull the wire off the left plug i can get the engine to start and run off the right cylinder. But if i have spark going to each cylinder, only the left one will fire?!? It's driving me crazy. Any ideas? Should this be posted elsewhere besides electrical?

That is odd
Try shooting Teazer and/or Bradj a pm and ask their opinions. Both are resident 2stroke gurus. You could also post it up in the 1-800-Cafe-Help section. More exposure means more help

I guarantee its the timing. And those bikes royally SUCK to time. A few thousands off and it will barely run. Do yourself a favor and buy a two stroke timing gauge. Screws into the spark plug hole. You're going to need it!

Plus one and throw the yamaha coils at a wall untill there gone. grab a set of 90s or 2000s coils off a ninja twin what ever cc. youll thank me later a 40 year old coil that sucked when it was new will be a bitch to tune