What are the differences in the older CDIs?

[sleddineinar]

I bought an '80 Enticer 340 for my son, as a project sled. It's a complete sled, minus a seat cover, but has no spark. I think I've narrowed it down to the CDI, the "little black box". It's an 8H4-20. I see that it is no longer available from the dealer. Are there other CDIs that might work? Or another source for them? I have found a place that makes an aftermarket ones, Fireplug CDI, I might try them. But I'm wondering if there is another model I could pull the CDI from and try it, to make sure that is the problem. Also the manual I have isn't real clear about testing the external coil, how would I test that?

 

[shaggyzr2]

Here is a list of sleds that used the same CDI
1979 EC540C
1979 ET250C
1979 ET300C
1979 ET340C
1979 ET340EC
1980 EC540D
1980 ET250D
1980 ET300D
1980 ET340D
1980 ET340ED
1980 SR540D
1981 EC340E
1981 ET300E
1981 SS440E

 

[Yamaha Nutz]

I should have a few good ones if needed

 

[Sleddugd]

If my tunnel starts with 8N6 and my engine 8H9 do I have a 79 engine in a 83 frame ?
My question is what mag/coil should be in it ?
Has 4 wires out of current one but 79 shows 5 ?