I have a 3.8 litre 165 hp Mercruiser in a 1987 Rinker.

I just bought the boat, and it has not been run in three seasons, thus I am
going through things very carefully before proceeding.

At first I had no spark whatsoever. I verified that it was getting fuel, and
it was (granted it could be old fuel).

Next step, rotor, points and condenser, because they were included with the
boat.

At that point, the engine would fire, but would not start. Not a problem
since I assumed I was on my way to a solution.

Today I bought a cap, wires, and plugs. I replaced the cap, but found that
the wires were the wrong ones.

After replacing the cap, the engine seems to backfire when turning over.
Note that it did not do this with the old cap.

I checked the gap on my points, and it is right around .020 with a feeler
gauge.

Admittedly, I might have the wires out of order, but having done this
countless times on my cars I was very careful to remove and replace one wire
at a time to ensure they were not mixed up.

Am I missing something obvious regarding the backfire through the carb, or
should I leave things alone until I replace the plugs and wires?

Thanks In Advance
Tim