Dennis, I'm sorry I'm explaining myself so badly. The long and the short of it is that I took the two coils out and and swapped them left to right and reinstalled them and the problem moved from 1 & 4 not sparking to 2 & 3 not sparking. Since everything else was unchanged and ONLY the coils were swapped, my conclusion is that one of my coils is bad. Do you know of any reason why a coil pulled from an '84 or '85 CB700SC wouldn't work if I put it into an '86? I ask because there are some cheap single coils offered on EBay for $20 that I'm looking at to replace the one I have that I think is bad. Graham, Dennis and everyone else. Anyone got a coil from an CB700SC that you're parting out and willing to let go of? I'd rather buy one from someone on this list than from someone I have no knowledge of on EBay. Cheers all,
Dennis G. - Seattle -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Dennis Hammerl Sent: 06 June, 2009 22:53 To: [email protected] Subject: [Nighthawk Lovers] Re: My CB700SC and the CDI unit OK, everything works, but it doesn't... right ? That is, all components work but they don't. AND, in any combination of inputs. Oh boy.. The coil frames ground to the bike frame at the bolts. Continuity from coil frame to bike frame ? I'm not there, take a closer look and check your work again. Moving the coils physically from one side to the other made one work that didn't before ? Mounting point corrosion ? --- On Sun, 6/7/09, Dennis <[email protected]> wrote: From: Dennis <[email protected]> Subject: [Nighthawk Lovers] Re: My CB700SC and the CDI unit To: [email protected] Date: Sunday, June 7, 2009, 1:19 AM Dennis, Yeah, I can see I did not explain myself well. Let me try it again: Part 1: 2 & 3 were sparking and 1 & 4 plugs were not sparking. At the 3P MINI, the schematic shows that yellow wire drives the coil for the 2 & 3 plugs and the blue wire drives the coil for the 1 & 4 plugs. I swapped the yellow and blue wires at the 3P MINI plug. This reversed which side of the igniter was driving which coil. After this swap, nothing changed. 2 & 3 were sparking and 1 & 4 plugs were not sparking. I made two conclusions from this: (1) Both sides of the igniter were working because both sides could drive the coil that made the 2 & 3 plugs spark. (2) Probably, one of my coils was bad in spite of it passing all my continuity and resistance tests. Part 2: I put the 3P MINI plug back the way it is suppose to be. I pulled the entire coil assembly out of the bike and reversed the two coils; left became right and right became left. I reinstalled the coil assembly. Now the coil that had been driving the 2 & 3 plugs was driving the 1 & 4 plugs And the coil that had been driving the 1 & 4 plugs was now driving the 2 & 3 plugs. I cranked the starter over and the 1 & 4 plugs sparked and the 2 & 3 plugs did not. I concluded that (1) The problem followed the bad coil when I reversed it with the other one. (2) All other components have been proven to work. This includes both pulse generators, both sides of the Igniter, the spark plug wires and the spark plugs. I think the only real mystery, unless I'm missing something here (very possible), is why the two coils both measured correctly on all continuity and resistance tests. I hope that's a better explanation. Dennis G. - Seattle -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Dennis Hammerl Sent: 06 June, 2009 21:56 To: [email protected] Subject: [Nighthawk Lovers] Re: My CB700SC and the CDI unit After reading this a couple of times, I think I get it. The mini plug wire swap didn't do anything but swapping the wires at the coils did ? That's the almost the same thing. Check for continuity in all those wires. At this point, take the wires off the live coil and switch to the dead one.. OK? Now do the same thing with the other pair. Problem moved ? Y~N ? What is the resistance of the plug caps ? From what you say, you can get spark from both coils, using different wiring configurations. That would mean both coils are OK. AND, if I get this right, you are sure both outputs from the CDI work as well. This leaves us with only the wires from the mini plug to the coils. Maybe I'm missing something in your description. --- On Sat, 6/6/09, Dennis <[email protected]> wrote: From: Dennis <[email protected]> Subject: [Nighthawk Lovers] Re: My CB700SC and the CDI unit To: [email protected] Date: Saturday, June 6, 2009, 6:10 PM Dennis, Yes, I think I understand it. I swapped the blue & yellow wires at the 3P MINI connector just before the coils. The problem did not change; 2 & 3 still spark and 1 & 4 do not. If I understand things, this fact is telling me that I have good signal from both sides of the Ignitor because now 2 & 3 are firing using the signal from the other side of the ignitor. So, if both sides of the ignitor are working, then my problem must be beyond the ignitor. I.e., the coils or their wiring. I pulled the coils out again and had a really good look at them. - I remeasured the resistance on both primaries and secondaries - all still good. - I checked for continuity on the wire that carries ground from one coil to the other - it's good. - I tested the primary's resistance and continuity from the coil side of the 3P MINI plug and everything was good from there. - I measured the resistance from the primary to the secondary on both coils and it was basically infinity. So, I can't see by using my VOM where the 1 & 4 coil is any different than the 2 & 3. My next step was to swap the coils and see if the problem moves. And it did. Now 1 & 4 are sparking and 2 & 3 are not. My conclusion is that one of my coils is bad but I'm pretty baffled as to why both coils seems identical when I test their continuity and resistances. . I'm interested on your thoughts on all of this, Dennis. Am I missing something here? Dennis G. - Seattle -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Dennis Hammerl Sent: 06 June, 2009 11:06 To: [email protected] Subject: [Nighthawk Lovers] Re: My CB700SC and the CDI unit You do understand what I'm talking about ? It's very simple, you're trading components to determine which one is at fault. The pins come out of the plastic connectors by inserting a small screwdriver in and moving the tang out of the way. I use a tool made for leather working. Study the plastic connectors first and make notes of where the wires belong for later. Your problem should move to the 2-3 set at some point. That's when you find the bad part. --- On Sat, 6/6/09, Dennis <[email protected]> wrote: From: Dennis <[email protected]> Subject: [Nighthawk Lovers] Re: My CB700SC and the CDI unit To: [email protected] Date: Saturday, June 6, 2009, 1:27 AM Beautiful. I'll be on it in the morning if business here is light. Thanks! Dennis G. - Seattle -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Dennis Hammerl Sent: 05 June, 2009 22:13 To: [email protected] Subject: [Nighthawk Lovers] Re: My CB700SC and the CDI unit I did say you could move the wiring around at the connector plugs to insure your diagnosis was correct. Now you really should. Go to 22-1 and you'll see that the 1-4 pair at the coil is the bl/w and Y. The 2-3 set is bl/w and Bu. Switching those pairs and still having the 1-4 set out would indicate the coil is bad. If the 2-3 set went out, move back to the CDI. Now you switch the yellow and white pair with the blue and white pair. That switches the pulser coils at the CDI. If the 1-4 pair is still out, it's the CDI. If it swaps and the 2-3 set is out, it's the one pulse coil that's bad. Yes, by all means, check for continuity at all wires. A similar failed part ? possible. Use your VOM to eliminate confusion and check all point to point wiring and grounds. --- On Fri, 6/5/09, Dennis <[email protected]> wrote: From: Dennis <[email protected]> Subject: [Nighthawk Lovers] My CB700SC and the CDI unit To: [email protected] Date: Friday, June 5, 2009, 10:46 PM Well, my new Ignitor unit came and I installed it and my bike still has the same symptoms. That is, cylinders 1 and 4 are not getting any spark. I sat down and had a longer look at the schematic and I can see some possible scenarios that might be consistant with the facts on hand. Those facts are: - I've measured the resistances of both my primary and secondary coils and my pulse generator coils and they all show continuity and resitances that are within spec. - I've tried two different Ignitor units (my original and the new one) and the system fails the same way with either (no spark on 1 & 4). Scenario # 1 is that the new ignitor unit is bad in the same way that the old one is, i.e. failing on the cylinder 1 & 4 side. I don't think much of this idea however - seems like too big a coincidence. Scenario #2: that even though the pulse generators both measure good on continuity and resistance, the one that sends the signal for 1 & 4 may, somehow, be out of place relative to the central shaft that spins with a magnet on it to generate the pulses. I'll be able to see this, I think, by cranking the bike and looking for voltage pulses coming up the cable from the pulse generators. If both sides have similar pulses, then I think this won't be the issue. If one pulse is low or mssing, then I'll open the pulse generator cover and see what's what in there. Scenario #3: one of the connectors linking the pulse generator cable to the Ignitor may be corroded and not passing signal. Frankly, this seems remote to me. The surfaces seem clean and I've plugged and unplugged them several times. Scenario #4: The wire that carries the 1 & 4 signal from the ignitor to the 1 & 4 coil may be open. I can run a simple continuity test to demo this. I know the ground wire and the 2 &3 wire from the ignitor to the coils has to be good as I've got spark on 2 & 3. Scenario #5: The wire on the coils that carries the ground from the 2 & 3 side to the 1 & 4 side may be open. Scenario #6: The connection where the 1 & 4 signal from the ignitor connects to the 1 & 4 coil may be corroded and not passing the signal. I've had this disconnected and reconnected and it seems unlikely to me like in #3. Dennis H., are you reading this? I'm looking at page 19-0 in my CB700SC manual and I'm wondering if I'm missing some other scenarios? Dennis - samadhi<soft|coda|muse>.com --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en -~----------~----~----~----~------~----~------~--~---
