Brain fart, need clarity - Coil / CDI problems? : SOLVED

Hey guys,

Long time, no post.

Since my last time on here I have built maybe 50 bikes, all with fully customized wiring. As many times as people say "Yeah the CDI is dead" or "The coils are fried" when I buy parts bikes...I always get spark out of them and get them running without needing to replace anything. Usually just crappy old wiring, fuses, etc.

I am working on an 1980 SR250 right now and I cant get any spark out of it. I have tested everything as listed below and it all seems to check out fine.

Here is the brain fart. Without pulling any other bikes out of the shed and buying batteries, testing, etc...

The coil has +12v at the Red/White wire ... but also has +12v at the Orange wire. Both are always +12v. Is that normal? I would think the Orange wire would see pulses from the CDI, not be a constant +12v. Have I found my first officially toasted CDI?

Do the pickups need some sort of voltage fed to them? Usually done by the stator... Which does show DC voltage out of the R/R when cranking the bike so I figured this was all good.

Coil Primary: 3.5 ohms
Coil Secondary: 26,000 ohms
Pickups (G/W to R/W): 700 ohms
Good grounds
CDI has +12v @ Red wire

Re: Brain fart, need clarity - Coil / CDI problems?

Wiring diagram is too small for me to see properly. If you have service manual it may have basic CDI tests?
I think in 1980 Yamaha was using 'cartoon' manuals which were pretty worthless though.
I was running workshop at Suzuki /Yamaha dealers in 1980 but have very little information from that time.
I think you had to send CDI to Yamaha for testing, I'll try and find out.
I remember there was a wiring fault that resulted in good CDI's being replaced under warranty, dealers got real pissed when they got charged for them when there was nothing wrong with part.
Check the wiring harness, it may have internal break at a connector,we fitted dozens of new ones, most before bike was sold or even on showroom floor

Re: Brain fart, need clarity - Coil / CDI problems?

The harness has been chopped to fit the new electrical I am running so its all 100% fused, soldered, and shrink wrapped well. Connections should all be rock solid... key word... SHOULD, I will check this first thing tonight.

Any chance someone has some insight on weather or not I should have +12v on both the "+" and the "-" side of the coil?

UPDATE:

So the salvage yard next to my work (yeah talk about convenience) had a CDI. Bought it and figured it was worth a shot...bingo

Plug it in, bike fires up no problem. Guess sometimes the parts are in fact just busted.