Time for new coils?

[Ericthejet]

1984 Ninja 900.
71000 miles.
Engine is fine all around, plug color is a dark copper, even on all four plugs.

From what I can tell the coils are the stock set that came with the bike.
Over time do they start to weaken enough to have an effect on matters of combustion?

Would it be a good idea to source new(er) coils?

Thanks.

[Kurlon]

If it's not having problems, RUN IT. Coils can and do wear out, but they are so unpredicatable that I wouldn't do preventative swaps on a clean running machine.

[richw]

What do turn to crap are the resistor caps and wires

Change them 1st to silicone wire and new caps

Throw in some Iridium plugs while you at it

clean the coils and maybe some spray water proofing

[butcher bergs]

Adjusted the air mix screws lately?