Motorcycle Repair: Kawasaki 500, two cycle engines, flash rust

Question
Last fall at the end of the season, my bike worked fine. I parked it in October, and tried to start it in nov and it would not start. It is  an older bike and I bought it after it had been stored for 3 years. The tank had a bit of rust in it  so I thought it was needing a good cleaning. I removed the tank and did an awesome clean with Phos acid, and then sealed  it with mineral oil to stop the flash rust. Before I reinstalled the tank, I used a syringe and injected fuel into the gas line prior to the carbs. It will not start.I checked and I am getting a good spark to the plug I know that there is fuel getting to the carb. I tried ether and I got no fire up but some "smoke". So in summary. I have spark to the plug. I have fuel to the carb I have a good battery, but I have a bike that will not start  any suggestions

Answer
Tim,

Having the year and model make it easier to
diagnose due to changes in design through
the years. Is this a single, twin or triple?

-It needs reasonable compression
to start and run well.
At very least 100 PSI.

-it might be flooded with fuel and need
to be cleared out or aired out.

-could be a faulty choke.

-ignition timing may be off.

-air filter plugged.

-bad spark plugs.

-plugged exhaust system.

-sucking air by carb intake tubes.

-two cycle engines can leak by crankcase seals
causing starting problems and smoke.

-four cycle engines need correct valve timing.