Carb Problem?

My 78 KZ650D1 has become hard starting from cold, instead of firing and revving to 4k on choke it slowly chugs up, rough running at cruise (4-5k) and backfires on deceleration. The idle hunts and its likes to quit at lights and to top things off, it likes to piss a little gas out of #1's overflow tube when put on the sidestand after a run.

I had the carbs cleaned and float valve seats replaced a season ago.

Running relatively new Dyna S, Dyna coils and wires. I've owned it since new and it ran like a top at the beggining of the season

Plugs #1 Very black and carboned and sooty
#2 Somewhat black and sooty
#3 & 4 Light tan

Compression - #1-130,#2-135,#3-130,#4-135

I'm not thinking ignition as #1&4 and #2&3 run off the same coil and pickup.

I've pulled the carbs, they seem clean (102.5 mains and 15 pilot), air screws- 2 turns out. Shot carb cleaner thru the pilot circuts.

What could be the problem, float levels?? I was plan to get some carb kits from Z1 and replace the 30 year O rings, gaskets, jets. Is there a simpler solution?

Maybe a vac leak somewhere like the carb boots? I'd go ahead and check the float levels also.

Air leaks will cause the engine to race... yours doesn't sound like it is racing. Try cleaning the carburetors focusing on the pilot and choke circuits and DO check the float level in each carb using the service fuel level method.

Thanks, I saw a diagarm in a thread for the Fuel Service Level method and will give the circuits another cleaning

I cleaned he carbs, shot cleaner through Pilot system and Choke system air jets in the venturi and checked the float levels (they were ok) Everthing is close to normal. No backfiring, cold starting ok. The carbs didn't appear dirty but must have been, maybe a dirty tank of gas.

One thing still, the #1 and #2 sparkplugs are still carboned up, #1 worse than #2, so I ajusted the air screws out for those carbs which diminished the carbon after a number of test runs
#1 - 3 turns out
#2 - 2 1/2 turns out
#3 - 2 turns out
#4 - 2 turns

Is this normal, what could be causing this? - worn jets, more cleaning required.

I cleaned he carbs, shot cleaner through Pilot system and Choke system air jets in the venturi and checked the float levels (they were ok) Everthing is close to normal. No backfiring, cold starting ok. The carbs didn't appear dirty but must have been, maybe a dirty tank of gas.

One thing still, the #1 and #2 sparkplugs are still carboned up, #1 worse than #2, so I ajusted the air screws out for those carbs which diminished the carbon after a number of test runs
#1 - 3 turns out
#2 - 2 1/2 turns out
#3 - 2 turns out
#4 - 2 turns

Is this normal, what could be causing this? - worn jets, more cleaning required.