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Discussion Starter · #1 ·
I have a "new" '79 CX500 that I took the valve covers off to clean the chrome as good as possible. Now that I've replaced them with multiple delicate efforts, the bike won't start. Any suggestions or explanation as to what I did or didn't do that wont let me start it?? Please help!
 

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A valve cover won't cause starting problems but what are you really saying. Won't turn over, wont come to life, wont stay running.



Simply forgetting putting the coil wire back on the plug would eliminate one of those.
 

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Discussion Starter · #4 ·
So I've searched high and low and tested for spark in each wire, to no avail. Either both Coils have suddenly gone bad or the CDI has become useless (I called and the service guy said CDIs rarely go bad. I feel like I might have "bumped" a wire or something that might have caused this. It turns over, gets gas, etc, but just won't start. If you any other tips/tests I can do, it would be much appreciated, as I don't want to take it to the shop before I even receive the title! Could I have affected a ground or something simple that I'm just not figuring out, even with the manual's assistance?
 

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Did you trip the kill switch? That's the only way to kill spark on both sides. Most cdi's that I have seen that died still produce spark just at the wrong time or only on one side. CDI's do die but if you just took the covers off and it ran prior then that's probably not the problem.
 

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Did you trip the kill switch? That's the only way to kill spark on both sides. Most cdi's that I have seen that died still produce spark just at the wrong time or only on one side. CDI's do die but if you just took the covers off and it ran prior then that's probably not the problem.


I thought the same thing about the kill.
 

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Discussion Starter · #8 ·
I originally tried the kill switch in multiple positions, just in case. I'll do it again while I check for spark, but I did try to no avail before my first post.
 

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How long was the bike down (offline, torn apart)? Is there fuel getting to the cylinders? Can you open the carb bowl drains and see if there's fuel in there?



Wait, I'm getting waaaaay ahead of myself, I don't know crap about these bikes yet. It's just the UJM troubleshooting button has been pushed. I'll slowly move back into hiding behind the curtains now.....



Sorry...(shuffle shuffle shuffle)...won't happen again....
 

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How long was the bike down (offline, torn apart)? Is there fuel getting to the cylinders? Can you open the carb bowl drains and see if there's fuel in there?



Wait, I'm getting waaaaay ahead of myself, I don't know crap about these bikes yet. It's just the UJM troubleshooting button has been pushed. I'll slowly move back into hiding behind the curtains now.....



Sorry...(shuffle shuffle shuffle)...won't happen again....




Most mechanical is the same just different. Give us as much details as you think are relevant and then all that isn't. Because two bolts on each side and a plug cap shouldn't make any difference in reverse order.



Did you remove anything else on the bike while doing this? Take of the seat? tank? Lets just call this need for overkill.
 

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perhaps.......pull the plugs,bending the HT. leads finally finished off a 30 year old wire
.......



you dont happen to have 2 plugs lying around your workbench,do you
 

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Discussion Starter · #17 ·
Yes, I had the tank and the seat off. Every possible wire I could have touched or that is there, appears to be connected. I tried the kill switch again in all positions, still with no luck. It just seems like there is nothing left to check and/or the cdi and/or both coils mysteriously went bad?
 

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Just a guess but check to make sure the green ground wire that attaches at the coil bolt towards the front of the bike is secure and is getting a good connection to the frame.



Fib
 

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A couple of things you might try. Unplug the black w/white stripe wire at the CDI. This takes the complete kill switch circuit out of the loop. Possibly a wire got pinched under the tank when it was re-installed. And also try unplugging and then repluging the connectors under the seat. You may have some corrosion inside that keeps good contact from being made. I had a situation once when I removed the carbs on my CX. After buttoning everything back up, it would only run on one cylinder. Some careful examining uncovered that one of the coil wires had been partially pulled out of the connector. The plug end was still in the plastic sleeve, but not making any contact with the female end.
 

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After further thought, I believe that green wire is the ground for my fairing so if you don't have a fairing, that wire may not be there. You should make sure those bolts are tight though.



Fib
 
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