Coil compatability 79 850

[AF_Bill]

So the coils on my 850 went out and I'm about to replace them with a set I got from my parts guy. The new(ish) coils came off an 82 650g. Now they ain't the same PN and I also noticed that the + & - wires are hard wired into the original coils where the 650 coils have 2 blades on the back.
I'm wondering of the coils from the 650 will work if wired up correctly for my 850. Please help.

[BassCliff]

Hi,

They'll work fine. The newer models went with the connectors instead of the soldered joints. My '80 850G still has the original coils with the soldered joints. I'll upgrade if they ever go out.


Thank you for your indulgence,

BassCliff

[AF_Bill]

Cliff, thank you very much. I'm guessing that the white is NEG and Orange/White is Pos?

[BassCliff]

Hi,

Cliff, thank you very much. I'm guessing that the white is NEG and Orange/White is Pos?

Yes. The other side should have a black/white wire for the negative.


Thank you for your indulgence,

BassCliff

[AF_Bill]

So I got the coils installed and wired up. BUT there's still an issue. When I get her to fire up, she idles at ~500rpm. I try to slowly roll the throttle and she dies. Is it possible that I have the two POS leads to the coils mixed up? HELP!!!!!!!!!

[BassCliff]

Hi,

The positive leads don't matter. It's the negative leads from the igniter that fire the coils.


Thank you for your indulgence,

BassCliff

[AF_Bill]

White is for the white coil and black is for the right correct?

[BassCliff]

Hi

Drat! I was going to look at a wiring diagram but my website it down. I'll have to call my ISP.

But I think you're right. The white wire is for the left coil and the black/white (black wire with white tracer) is for the right.



Thank you for your indulgence,

BassCliff

[AF_Bill]

Ok thats the way I hooked them up. Could it possibly be that the boots aren't making good contacts with the wires?

[BassCliff]

Hi,

I suppose that's possible. Did you use new plug caps? Did you install suppression wires?


Thank you for your indulgence,

BassCliff

[AF_Bill]

The caps and boots look in great shape so I didn't get new ones. What are theses supression wires you speak of?

[BassCliff]

Hi,

Suppression wires have the resistance "built in". They are used mostly to cut radio interference in cars. You can use either NGK plug caps (usually 5K ohm) or suppression wires, but not both. Normally you'll want a regular copper spark plug wire and the NGK plug caps.


Thank you for your indulgence,

BassCliff