I recently purchased a 1979 CX500 for $100, needed a triple bypass, which has been done.
When I bought it the previous owner said it wasn't charging, which I confirmed after I got it running once, before I did the bypass.
It was very difficult to get it running then, but I did manage to get it fired up (somehow) to test the Voltage output. THe three yellow wires coming from the stator where all shorted to ground.
So I did the triple bypass, put in a second hand stator that I got off ebay - this stator was a fresh, unused rewind from Custom rewind, never used since rewound.
The stator resistance check was perfect when I had it mounted in the rear case, before assembling the engine and putting it back togeather. FWIW, now I just checked it again, bike fully assembled, and all the resistance checks are within spec except for the last one (5/9) which is the "Source Coil Low Speed". it should be in the range 315-385, I'm getting 190 ohms. Don't know if that is related to my "won't start issue now though. The three yellow wires test good, none have continuity to ground, and they all have continuity to each other.
I did get it to run once after reassembly from the triple bypass engine R&R, but it was not charging which I suspect is due to a fried voltage regulator, now that it has a good stator. It was very hard starting like before, and it wouldn't idle under 1500 rpm. I took it down the road a bit and it ran really good above about 5 or 6k right to redline, but below that it was a bit doggy. It ran, but it was lacking any power below 5 or 6K, Idle was ok, as long as it was set to 1500-1600. When I shut it off after that ride, I have not been able to get it to fire now, not even a pop or spit.
I took apart the carbs and cleaned them, they didn't look all that bad inside, and blew out all the air and fuel passages and everything seems to be fine. Also, if I try to start by spraying starting fluid in the carbs, I still don't get any fire. Take the plugs out and crank it, I get blue spark, although it may be a little weak. I don't know what to expect visually on these things.
There are obvious indications of wiring overheating near the two red connectors, down near the starter solenoid - red and red/white wires and the two associated plugs, one attached to the regulator, the other to the fuse holder and battery. I have replaced/repaired those wires. At some point in time it looks like there was a short to get these wires melting, but no short now.
I just did the CDI test that Reg in Bristol describes here:
CDI test in other thread
I get about 25 volts initially when I start cranking and it drops off to about 3 or 4V, both sides the pink and yellow leads off the CDI box. He says I should see 150-200V??
If that's the case, is my CDI Box shot?
The way I see it now, I need a voltage regulator and a CDI box. If anyone has any additional tests I should run to help verify, or other input, I would greatly appreciate it. Thanks .
I wish I had a spare CDI box to try....that would make it a lot easier.
Dave
When I bought it the previous owner said it wasn't charging, which I confirmed after I got it running once, before I did the bypass.
It was very difficult to get it running then, but I did manage to get it fired up (somehow) to test the Voltage output. THe three yellow wires coming from the stator where all shorted to ground.
So I did the triple bypass, put in a second hand stator that I got off ebay - this stator was a fresh, unused rewind from Custom rewind, never used since rewound.
The stator resistance check was perfect when I had it mounted in the rear case, before assembling the engine and putting it back togeather. FWIW, now I just checked it again, bike fully assembled, and all the resistance checks are within spec except for the last one (5/9) which is the "Source Coil Low Speed". it should be in the range 315-385, I'm getting 190 ohms. Don't know if that is related to my "won't start issue now though. The three yellow wires test good, none have continuity to ground, and they all have continuity to each other.
I did get it to run once after reassembly from the triple bypass engine R&R, but it was not charging which I suspect is due to a fried voltage regulator, now that it has a good stator. It was very hard starting like before, and it wouldn't idle under 1500 rpm. I took it down the road a bit and it ran really good above about 5 or 6k right to redline, but below that it was a bit doggy. It ran, but it was lacking any power below 5 or 6K, Idle was ok, as long as it was set to 1500-1600. When I shut it off after that ride, I have not been able to get it to fire now, not even a pop or spit.
I took apart the carbs and cleaned them, they didn't look all that bad inside, and blew out all the air and fuel passages and everything seems to be fine. Also, if I try to start by spraying starting fluid in the carbs, I still don't get any fire. Take the plugs out and crank it, I get blue spark, although it may be a little weak. I don't know what to expect visually on these things.
There are obvious indications of wiring overheating near the two red connectors, down near the starter solenoid - red and red/white wires and the two associated plugs, one attached to the regulator, the other to the fuse holder and battery. I have replaced/repaired those wires. At some point in time it looks like there was a short to get these wires melting, but no short now.
I just did the CDI test that Reg in Bristol describes here:
CDI test in other thread
I get about 25 volts initially when I start cranking and it drops off to about 3 or 4V, both sides the pink and yellow leads off the CDI box. He says I should see 150-200V??
If that's the case, is my CDI Box shot?
The way I see it now, I need a voltage regulator and a CDI box. If anyone has any additional tests I should run to help verify, or other input, I would greatly appreciate it. Thanks .
I wish I had a spare CDI box to try....that would make it a lot easier.
Dave
