KZ550 misfires

Hey everyone. Last week I adjusted the float heights on my 81 KZ550. The previous float heights were causing gas to overflow into the cylinders and air box. I adjusted it to 18.5mms and put the carbs back on the bike. Now it idles rough and dies when I give it throttle without the choke on. When it idles the rpms are really low and it misfires. Does anyone know what's making it do this?
Thanks

nickleo373 wrote: Hey everyone. Last week I adjusted the float heights on my 81 KZ550. The previous float heights were causing gas to overflow into the cylinders and air box. I adjusted it to 18.5mms and put the carbs back on the bike. Now it idles rough and dies when I give it throttle without the choke on. When it idles the rpms are really low and it misfires. Does anyone know what's making it do this?
Thanks

Would suspect leaking float valves were causing the overflows, and that the overflows were largely unrelated to the float heights.

Would correct the float valves, and re-adjust the float heights, using the clear tube test method.

Good Fortune!

Thanks for the reply. I noticed when putting the floats back on the carbs that the piece with the spring that opens and closes the valve will slide down when the carbs are placed on the bike. It doesn't fall out of place but the whole piece drops down with the floats. Is this normal or are they broken?

Yes, that is normal. If you remove the float they should fall out. If they don't they may be stuck in the seat causing your overflow problem.

They open and close depending on the height of the float. Make sure the seat and tip of the valve are not worn.

Thanks. They were stuck in before I cleaned the carbs so thats how I thought they were supposed to be. It's all freed up now so it should be alright

I've got an 83 kz 550H, which I am going to readjust my float heights on. My manual indicates a fuel level of 6mm +/-1mm below the top of the float bowl.

Because these float needles do not have a clip on them that holds them to the actual floats (like most others I've seen) the needle just falls in and out of place. So what you are seeing is normal.

I just made sure the valves aren't clogged or stuck and I set the floats using the clear tube. I put the bike back together and now it will idle only with the fast idle screw turned all the way out. It'll idle like crap for a few seconds and then dies. Does anyone know what this could be?

It sounds like you could either have set the fuel level incorrectly, or have a vacuum leak, or still plugged up slow/ pilot circuits.

Turns out it was a dying battery. I charged it and the bike will turn on and idle like normal. I believe my #3 cylinder isn't firing because after revving the bike the #3 header is warm while the others are too hot to touch. The first thing I want to check is the fuel level but I can't do the clear tube test because the float bowl drain screw is seized up. Ive been spraying liquid wrench and pb blaster on it for months and it won't come out. Is there another way to check the fuel level?

In my signature, there is a link to my TK22 site. In the maintenance section, there is a description on how to roughly set the fuel level while dry, and carbs off of the bike.

If the fuel needle has a ring aroud the tip with a noticeable ridge, the needle and seat should be replaced.

Thanks Loudhvx. That was helpful. How do you take the float bowls off with the carbs on the bike to make adjustments after I reset them? Mine have the JIS screws that came with the bike and I can't find a screwdriver anywhere that will fit between the crankcase and the carbs

nickleo373 wrote: Thanks Loudhvx. That was helpful. How do you take the float bowls off with the carbs on the bike to make adjustments after I reset them? Mine have the JIS screws that came with the bike and I can't find a screwdriver anywhere that will fit between the crankcase and the carbs

Good question! Here's what I use. A little modified to JIS screwdriver bit in a socket with a 1/4" ratchet. A mirror helps so you can see the screws as you seat the bit. Ed