Atomizing backwards out the carb.

So I got a free 81 KZ650.

This isn't my first rodeo; It's gotten personal.

So how it stands:

Turning it is has compression on all 4 enough to sputter.

I rebuilt and boiled the carbs, etc. but they were stored right. And as far as I can tell everything is clean enough to at least run. (I didn't yank the actual choke tubes or pull the little idle air jets but they sprayed cleaner through ok; plugs are wet and it backsprayed fuel so I assume they flow). If there's something janky on these slide carbs let me know and I'll dig in again.

But i do a better job than most shops.
Its also got a jet kit (I hate aftermarket pipes and pod filters) so who knows maybe its that.

Spark is OK on all 4 (maybe weak I can't hear it but motorcycles are weak compared to cars and CDI doesn't always give that fat blue), and I switched both the rotor on the ignition and wires looking for mechanic mess ups. Danacoils are new (Gaps, etc).

Its got a new bat/ crank may be a tad slow but its always hard to tell. I mean if they can kick its probably faster than that.

Anyways, it wont start even if I give it wd40. Spark and fuel... Instead it sputters the wd40 back out the carbs. And it is a 0 no start just plane cranking (timing covers off so I see its moving).

I'm wondering at this point if the ignition cube is shot/ sparks just way to weak or off time badly. Anyone got the test specs/ ideas where in the harness I should dig? Maybe a parasitic rectifier?

It died by sitting so the mechanical things I suspect (lost cam tooth, etc.) are unlikely and with 10 years mechanical experience they at least try to run.

Wd40 is easy to light.

I've a harness diagram but man I hate digging through them...

Just looking to see whose had this.

Could be Tight valves.
Steve

I'll give that a check. But it would be odd if a guide scrubbed while sitting.
Thats more of a breakdown thing. Think they'd sit and get lose in rusty guides...
I've verified they are at least moving.

I just tore down the carbs 110% so its not going to be them.

Make sure the ignition rotor is facing the correct direction.

With 1 and 4 at TDC, the pointer of the ignition should be pointing backward toward the pickup with the black and blue wires.
The coil with the black wire fires cylinders 1 and 4.
The coil with the green wire fires cylinders 2 and 3.

Did all that. Its right.
Waste spark is at least simple.

But... As I was compression testing I figured I'd check that spark again... And none now from both coils.

Battery still had barely enough to turn the motor; it should spark if it can kick a starter. And it turns out with proper starting fluid it can almost go.

So spark is weak but on time. Need the voltages for the signals and coil leads to catch the drop it seems. And resistance for the ignition cube. I put if here because it was seeming electronic and not primary ignition per say.

I just can't find it no matter what kinda google fu I use and the 20 buck manuals don't tend to have that kinda info.

Its probably back atomizing from flooding. Doubt 2 new coils are bad

You can test for spark without turning the motor. You just tap the pickup center with a screwdriver lightly. Make sure both plugs (for each coil) are able to spark. That is make sure there is a complete path for the spark (the plug bodies touching each other or the motor).

If the battery is so weak it barely turns the starter, it will not have enough power left to fire the ignition. It may have enough poop to fire the plugs if the bike is kick or bump started, or it may not.