1985 Honday Odyssey has no spark. It will turn over. The following has been replaced:
Stator
CDI (Capacitor Discharge Ignition)
Rectifier
Grounds have been cleaned
Replaced old wiring harness with another one
Spark plug
Coil
Each wire has been inspected on both harnesses
Each connector has been cleaned
Engine switch has continuoty in off position. No continuity in run.
Key switch has no continuity no matter what (open or with a jumper wire).
Getting 3-4volts to coil
Getting volts to the plug
It's in neutral (not drive or reverse)
What are your thoughts or ideas?

Welcome new guy.
This site is very very dead now but there is an incredible amount of info here.
Most of us old timers have left but make an occasional appearance.

Here is a thread I did in 2019 that has a LOT of info in it.
viewtopic.php?f=2&t=18393
You can click on anything highlighted in blue and it will take you to a thread.
Also there are a lot of pdf downloads with important info. One of them is a color wiring schematic.
It sounds to me like a wiring issue. Somebody screwing around with the wiring and now it's a complete mess. That's what it sounds like to me.
The Engine is in rubber mounts. Make sure the wire from the Engine case is going to ground. There must be one attached. It's located right next to the counter balancer dip stick.
The key switch is why I believe what I believe based on what you are telling us here.
CO

I have to check on my 91yr old mom so I will check in here later tonight.
You have to be very very patient now for replies due to the fact this site has lost most of it's members due to age.
CO

Hello,
It's new lady! :)
Thank you for the additional info. The wire from the Engine case is grounded out. The ground has also been cleaned and put back on. I will dig through the other items that you provided. I do have the schematics already.

Well then welcome new lady
I'm a certified millwright and not an electrician. Electrical is my weakest trade.
I have tried to read your intro slowly.

You said: "Engine switch has continuoty in off position. No continuity in run."
That makes sense because in the off position it grounds the CDI (Capacitor Discharge Ignition) box and kills the ignition so you get continuity.
In the run position, no continuity so it don't kill the ignition. So this seems to be working.

You said: "Key switch has no continuity no matter what (open or with a jumper wire)".
I don't understand this part because you said: "Odyssey has no spark. It will turn over" so the starter works.
Starter can't work if key switch ain't sending power to the start switch.
CO

Just for fun have you tried to see if you get a strong spark at the spark plug by using the pull start ??
That would indicate that your battery crap ??
Just wondering.

On a side note: I have actually had to replace the entire tension lead on the ignition coil. The wire was damaged and corroded inside the rubber coating. These things are ancient. I know you replaced it but it's just another thing to look at. Not likely that two are toast. You did say that you get a small amount of voltage at the coil so I wonder if the battery is junk which is why I asked you try the pull start.
CO

Did you shear the key on the flywheel ??
Did you check it ??
CO

Verify you have the key on and the on off switch on

Verify the spark plug your using is good on another machine, even a lawnmower can be used. Have found brand new plugs bad from the factory...

On a FL350 first check for spark by removing the spark plug and pulling the recoil starter, using my fading memory the FL350 had problems if you have a weak or bad electric starter you will not get spark, the extra current draw from the starter affected the spark.

The next thing I do on a NO SPARK situation for Pilots, odysseys, motorcycles, snowmobiles, is to unscrew the spark plug boot from the spark plug wire then strip back about 3/16" to 1/4" of the spark plug wire and check for spark using the recoil starter, just hold the stripped end about 1/8" away from the head, if you have spark then cut the wire flush with the end of the spark plug wire, screw the spark plug boot back in and check for spark again with the spark plug attached. The problem usually is a bad connection between the wire and the part of the spark plug boot that screws in. (corrosion)

NOTE: Have a second person handy to pull the recoil starter so you DO NOT GET SHOCKED

Let us know how you made out.

Any luck?