TOPIC:

Rick H. wrote: Congrats on making this determination Vabi! How did you finally figure this out? What are the floats made of?

Rick H.

Plastic.
I've sinked them forcefully (with small weight) in a glass filled with fuel. Next morning, when I've removed the weights, they emerged, but only by half (2 of 4).
One side was floating, the other was not. So, we can agree that another side is not buoyant. It's probably damaged somehow.

There is a process called osmosis. It's similar to corrosion but it only happens with plastic.

Nevertheless, new floats are installed already. And solenoid valve. With petcock converted to ON/OFF mode, new needless and floats, and solenoid mounted on a tank I don't expect any leakage anymore.

Nessism wrote: Yes, good job. I've never seen a KZ Keihin or Mikuni float sink but these are TK's so...

As an aside, I rehabbed a ZX6 one time where the floats are hollow plastic. One float was filled with gasoline and sinking so it got replaced. Tossed the gas filled float in my tool box where it still sits more than a dozen years later, and it's still full of gas.

Let the fuel in, but don't let it out!

I had to take a break from my bike to take care of my work.
Now, I'm back.
I guess I'm almost there.
After carbs rebuild she runs great warmed up.
She starts immediately (completely cold, within a first second, with full choke on).
When she's warmed up she revs up instantaneously and settle's back down to idle (1100 RPM) without hesitation (Choke OFF).

There is always a but...?

She won't rev when on choke and cold. She bogs down immediately if I try to rev her up when on choke and cold.
It takes at least 5-10 min for her to warm up, and then I have to start her up again without a choke.

Is that normal?

Somebody else here with more knowledge than me might tell me I'm totally on the wrong track here, But I would guess it's bogging down when the choke is on because It's running overly rich when the choke is on. Or it could be that the carbs aren't able to create enough vacuum through the choke to pull fuel when you open the throttle.

Personally, I try to turn the choke off as soon as possible and rev it until the RPMs stabilize where they should.

It's normal for the bike to run sluggishly when cold but what you describe seems a little excessive. When you cleaned the carbs did you make sure the choke passages are all clear? I check them by first removing the choke plunger and putting the carb spray nozzle in the little hole at the very bottom of the plunger passage and squirting. You should see the spray come out the tube on the bottom of the carbs. Then make sure the passage in the float bowl is open. It sounds like you have at least some of these passages plugged still.

Nessism wrote: It's normal for the bike to run sluggishly when cold but what you describe seems a little excessive. When you cleaned the carbs did you make sure the choke passages are all clear? I check them by first removing the choke plunger and putting the carb spray nozzle in the little hole at the very bottom of the plunger passage and squirting. You should see the spray come out the tube on the bottom of the carbs. Then make sure the passage in the float bowl is open. It sounds like you have at least some of these passages plugged still.

I've got it. Carbs had to be synced. They were WAY OFF after rebuild.
When I got the engine warm enough to idle without a choke I've synced them.
What a beautiful music when you rev it up and let it rest at idle.
What a joy when you start your bike at 30 degrees (0° C) and it starts like she's just been waiting for you to push that button.
Me Happy!!!
Thank You Nessism! Thank you for your guidance.