CDI is Toast. Payday is FRIDAY. Anyone have any dirty hacks?

[Wisski]

So I'm very sad. I had just gotten the entire peddle assembly replaced on my Frankenbike, and accidentally jimmied the sparkplug boot. Took it off to re-seat it, and the guts of the boot just fell right out (actually, pushed out by the spring inside). This disappointed me, as I have no replacement, but I figured I'd just slide the wire (which has a copper core) over the spark plug tip (which was a perfect fit). I thought it was working fine, as the bike started right up, but it appears that the CDI didn't much like this, because about two miles down the road I lost all power. I tried a couple hill-assisted starts, and amazingly, i managed to get spark, but only above 25mph. Found out the hard way that engine RPMs had to stay high, otherwise, no fire, engine stall, and Mo' Peddling. I'm guessing heat conducted into the CDI through the wire, and destroyed something, I can't imagine what.

So now I have a Mo' Peddle, and a CDI that the multimeter confirms is shot. I still have a week worth of work to go to, and an 8 mile bike ride to get there. Anyone have any dirty hacks for getting spark? I have no SCRs, and the only HV transformers I can get my hands on are the kind that sit on the circuit boards inside CRT and LCD monitors. I'm handy putting circuits together, but maybe not so much on designing them. Also, I'm lazy as heck and don't like peddling 16 miles a day. PLEASE HELP!

 

[G-Superior]

Never seen that happening because of that but you can try to take it apart and rewind it all up with new (second hand from something else like a transformer but it has to be the same diameter and lenght!)
Poople used to do that a while ago with old engines and some still do, so you can give it a try plus the cheap copper that the chinese use is probably no good compared to copper from a high quality transformer
All you have to do is:
Get rid of all the plastic that there is around it to seal it and remove the wire put some new one in and then seal it up again with electrical tape! Easy!
Godd luck
G-Superior

 

[adb140275]

bake it in the oven at 350 degrees for 25 minutes, and allow it to cool completely off before trying to use it again. this normally doesnt work, but my friend got it to work once. good luck

 

[Wisski]

All you have to do is:
Get rid of all the plastic that there is around it to seal it and remove the wire put some new one in and then seal it up again with electrical tape! Easy!
Godd luck
G-Superior

:-/ I was under the impression the entire box was filled with epoxy...Excuse me, I have to go cut open my CDI now!

 

[Al.Fisherman]

Something else must of happened. There is no way that a wire hooked from the CDI directly to the plug would cause the CDI to burn up. It has to be something else like a CDI ready to go. Every engine that the spark plug wire is made with actual wire in it connects from the CDI to the spark plug itself. The wire in the CDI or plug might of been having interment contact, and that caused the CDI to die. You could use bare wire from the CDI to the plug and run the engine..it will be a shock hazard but will run.

 

[G-Superior]

:-/ I was under the impression the entire box was filled with epoxy...Excuse me, I have to go cut open my CDI now!

tells us how it goes! If people used to do it and it worked you should be able to get it back to life! Hehee
G-Superior

 

[Wisski]

Al - It was just a guess (I'm not a mechanic type, but trying to become one). I found the REAL problem when the new CDI came in...

The ground connection on the magneto coil is totally buggered. Intermittently it will be conducting, and that's what threw me, cause when I tested resistance on the coil, it was about where it should be instead of wide open. I tested it again after the new CDI came in, and NO GROUND. grrr. Some creative use of solid core wire and solder has solved the problem, somewhat. I can't take it above 25, otherwise vibration and/or heat compromises the connection, but it'll run now...with either of the 2 CDI units I've got -.-;

So new magneto coil is on the way. *sigh* I HATE trying to troubleshoot a system that has a sporadic-contact issue I'm unaware of. WAAARGH!

 

[GearNut]

The ground connection is notorious for being what is called "cold soldered" from the factory. The worker melts solder onto the connection until it looks good.
This type of solder connection has poor adhesion between the parts and a higher resistance through it.
A proper solder connection is made when the connector and wire are both heated to the point where the solder will melt when touched to both of them, soldering iron removed first.
The wire and connector parts will have a very good bond to the solder and a lower resistance will be had throughout the connection.
It will also be darned near vibration proof.

 

[Al.Fisherman]

The ground connection is notorious for being what is called "cold soldered" from the factory. The worker melts solder onto the connection until it looks good.
This type of solder connection has poor adhesion between the parts and a higher resistance through it.
A proper solder connection is made when the connector and wire are both heated to the point where the solder will melt when touched to both of them, soldering iron removed first.
The wire and connector parts will have a very good bond to the solder and a lower resistance will be had throughout the connection.
It will also be darned near vibration proof.

Out of all the engines I've bought ALL had a crimped terminal, secured under the coil mounting screw, for their ground connection. As far as the White wire, I cut it at the coil. The blue and black wires are removed and replaced with a single non spliced higher grade wires to the CDI, which is under my gas tank. I do this before gas is ever put into the tank.

 

[machiasmort]

Gearnut describes a process called tinning. What you do is heat up and coat both joinging contacts with solder sepperately.

You then proceed to heat them both together (to join them) so a good electrical bond is obtained!