Odd starting issues

The bike was parked last season with hard starting issues and bad fuel delivery problem, but with choke and enough turning over it fired up and idled a bit high/roughly.

Before trying to trouble shoot it this season I decided new spark leads could only help so I took some leads out of a parts car and cut them to size.

Now when I try to start it it BARELY turns over and will stop until I let go of the ign button and then push it again, I might get 1-3 revs before I have to push it again and I smell a bad smell... like eggs, I'm assuming it's the battery venting into the overflow tube. What gives? The battery tested just under 13V with a multimeter so it's not undercharged.

I put it away running and now it's FUBAR, I think my KZ got miffed at me for not paying it any attention over the winter...

BUMP

This is an 82 650 CSR, elec ignition.

when batteries start to smell like rotten eggs it means they are junk.time to buy a new one.put the charger on it and it will probably get hot to the touch.also indicates a bad battery.

The battery is less than a couple years old. I tried to keep it charged over the winter but it may have gotten a little low, but it still turned the engine over normally until I changed the plug wires?

I have no idea why it could possibly be doing this?

Anything worth looking at before I spend money on a battery?

I hear parts of the charging circuit (regulator etc.) can cause the bad smell as well? Like I said, my multimeter read a normal-ish 12-13V?

If not already done ---

Check fluid level in battery, add distilled water if needed, and charge the battery. Assure good solid ground connection where wire from negative battery terminal attaches to the engine or frame.

Would install brand-new NGKB8ES sparkplugs and try again to crank up the engine.

With battery fully charged, check visually for good fat blue spark at plug tips.

Measure voltage at coil primary. Compare with battery voltage across terminals.

Then -- assure correct ignition timing (static method if won't crank; dynamic method with strobe-type timing light if will crank and run). Also assure proper operation of advancer unit by watching it move back and forth with changing rpm.

When running, measure voltage across battery terminals. Should be about 12 volts when at rest with ignition turned OFF. With engine running, should measure about 14-15 volts at 3-4000 rpm.

Next -- do compression test, and assure correct valve clearances.

Last -- address carbs. Might be a clogged pilot circuit.

(Undoubtedly other things I'm overlooking.)

Good Luck!