hartleybiker

thanks easternrider i will chec secondary resistance as shown. primary resistance was good. as for the "electro-tester" in the schematic, I don't have one of those,

Yes, I returned it to original connections and rode it up and down the road and only the front two are firing. I should point out that I do get spark on the rear cylinders when the starter is turning over the motor, but not once the motor has begun to fire. Does the TCI have a different behavior when starting the motor, and then switch to a "normal operating setting" or something like that? Just a thought. This has got me stumped. Any ideas or help is welcome! Anyone near Atlanta with a spare TCI I could try?

Ok, so I switched the ignition coil connections coming from the tci front to rear and rear to front, just to see what would happen. I got multiple, reliable spark on all four cylinders (using the extra spark plug method) however, the motor would not crank. I assume it wouldn't crank because the timing was mixed up since the coils were switched. When testing the ignition coil resistance at the tci connector plug, I get 3.2ohms on all 4. That's the primary resistance right? How do I test the secondary resistance, or do I have those two terms mixed up?

Well, I soldered all connections where the pickup coil connector used to be, but no change in symptoms. I will now check the coils and plug wires, etc.

Dingy....Thanks for the wiring diagram link.. it turns out I was testing the wrong plug near the damper knob! I was testing the connector coming from the rectifier (also 6 way plug with one left blank) After comparing the wiring colors, I found that the P.O. deleted the pickup coil connector as I know many people do, HOWEVER, the connections weren't soldered or crimped or anything resembling decent electrical work, they pulled right apart with no effort... Just some electrical tape and a prayer I think! Pickup coils all measured 120 ohms so I'm going to solder all connections and hopefully that will help. I will post results.

Squidley....When you say spark plug caps, am I assuming correctly that you are referring to what I call the spark plug "boot" aka the black rubberized connection point to the actual top of the plug? If so, then yes, they were already part of the wire set I installed. My pickup coil connection point near the damper knob was very clean and I got continuity through it, but i don't remember my ohm readings. Thanks for the tips everyone, I will post my findings with the ohm meter soon.

New to the forum. I have looked over a lot of threads on rear cylinder no-spark conditions and it has been very informative, but here is what I am experiencing. Recently got this bike (83 VR) in trade. P.O. said " rear cylinders aren't getting spark", and that he tried installing new plugs (I removed and confirmed that they are new plugs and gaps are all the same) and believed it was a bad TCI. So I had a tech open up TCI and replace all those problematic diodes and one capacitor that appeared to have "blown". Ok, now with 4 new plug wires here is what I get: Front cylinders fire just fine, rear cylinders only spark once, as the starter is beginning to turn over the motor, and then no spark after that. My testing method is a spare spark plug grounded to the engine case. I have checked the pickup connector along the frame, and the connections to the TCI. None were corroded or dirty, and the inside of TCI showed very little corrosion as well. All TCI harness connections seem to be in spec with what I've read in most of these threads and I got continuity through the troublesome pickup connector on the frame.. I have not yet switched the connections to the coils from front to rear to see if that changes, but the P.O. claimed to have done so and that the rear cylinders worked. Also worth mentioning, on a test ride, I experienced a sudden surge of power at 1/4 throttle that felt as though the rear cylinders kicked in for about a second. Any ideas?????