kz900 1976

1976 KZ 900 starts but won't idle, plugs looked wet when i took them out. Static timed the engine, carbs looked synched. (29 mm smooth bores) Cylinders don't all seem to be firing until I rev the engine. Dyna S ignition with 3 ohm accel coils. Done all the things I have been told on this site. Have not repacked coils yet. Any ideas for me here.

Need more info.
Have you checked for quality of spark ? Did you put in new plugs and recheck how motor runs
Define sync looks OK ??????
Condition of carbs and rebuild status.
Compression ?
Condition of valves and seals
Valve lash ??

Also, have you done the water spray test on the exhaust pipes? That will tell you which cylinders are firing and which aren't, if you can get it to run long enough.

Sounds like your bike is running a fat air/fuel mix.
One of the float needles is stuck or enrichment circuit Problem.

checked spark and all 4 have spark, have to rev engine to keep it running so sync is at 2500 rpm or so, new 8 bes plugs, Carbs cleaned and all jets cleaned and no new parts except for float bowl gaskets and o ring on air screw adjusters. Checked compression and all cylinders seem ok, may have to get a new compression checker. Valve clearance within tolerance or real close. Don't know about valve seals. What is valve lash?
Thanks for your help

Checked float needle when I cleaned carbs all seemed fine.

what is enrichment circuit

Do you have a manual ?

Valve lash is clearance between cam lobes and valve shims which are in valve buckets over valve retainers and valve stems

You need compression, spark and fuel, and you say you have all three. The engine starts and runs but won't idle. Sounds like a carb issue...possibly float height.

Check your ignition Timing/Points gap

Scirocco wrote: Check your ignition Timing/Points gap

No Points Dyna S

He do a static Timing only.