[fmcmla]

Hi,

Been doing lots of reading and troubleshooting but still can't figure out if my '88 750 really needs a replacement CDI. Bike has been running fine for several years straight. Rode it for the first time this year about a month ago. No issues at the time. Wasn't able to get it started the other day. Can get spark from ignition wires going to cyl 1 and 4 but not 2 and 3. Same results when the coils were swapped, indicating that coils aren't bad. Primary and secondary resistance for both coils are within specs. Also tested resistance at signal generator terminal and that's within spec. Continuity between wires at ignition coils end and CDI plug end all are solidly connected. Anything else I should try before buying a replacement CDI? Any other tests I can perform on the signal generator at the rotor end? I don't have or know anyone with a compatible CDI to test with.

 

[mark_E]

I think you've covered everything. Sounds like you need a new cdi.

 

[fmcmla]

I should also add that voltage at both ignition coils' 4 spade connectors (2 connectors per coil) were approx 11V when ignition is turned ON and approx 7V when cranking.

 

[Gixxerider86]

I went through the same problem on a slabby Im currently fixing up. you can slide the circuit board out from the CDI box. look carefully at all the solder points, check for even the slightest, smallest of defects. My slabby had the same problem and wouldnt fire on cylinders 1 & 4, it turned out to be the white wire coming from the coil that goes directly to the CDI, the solder on the circuit board had a hairline crack. soldered it back up, now it runs like a new bike. look at a wiring diagram and verify that the power wire from the coil goes directly to the CDI

 

[icprey]

There's quite a few guys on here from Alberta, I'm sure someone has one to test try. If you were here in QC I'd be glad to help. Not sure how you can search those guys out?