1981 KZ1000 J-to-K build

Started getting into the carbs tonight... hmm... Got the floats pulled, one of the valves didn't have a filter screen under it, and two had the screen upside-down. There were some bits under the screens that needed flushed out. Didn't find any more grit around the idle jets, but the jets were almost completely clogged again. I'll get to the pilot screws later and see what things look like there. I also noticed that one of the towers for the float pins has broken off. No sign of the piece, and I haven't a clue if that was broken before. It split around the pin so half the support is still there, Ugh.

Another odd thing... Yesterday after pulling the tank I ran the engine until the carbs were dry. I figured there was still a little gas in each so I drained the bowls on the bench. Most were nearly empty but the #2 carb was still pretty full of gas. I'm guessing that means I'll find a lot of junk behind the pilot screw. Hopefully that means #2 wasn't working at all and the bike will run smoother once I get this figured out. It would also explain why the left side was running so much cooler, if only one cylinder was firing.

I decided to crack open one of the carbs from the other set, wow that's nasty. Gas sat in there so long it turned to varnish and really gummed it up. I think cleaning up this set might be a good Winter project, see if they're in better condition. The set I'm using now were the originals for the J, I *think* the other set were original to the K. There are some subtle differences, like the J carbs have air adjustment screws on the sides. There's several parts that I only have one good set of, hopefully the bodies of these other carbs don't have any flaws like the float mounts.

So for now I'll see what I can clean up the original carbs, at least get some practice with their insides, and see if I can make the bike run with them.

Finally got in the new air filter today... hmm I feel like I'm missing something. It fits loosely in the air box. There's like a 1/2 inch gap behind it so the foam at the front side doesn't seal up tightly against the air box. The parts diagram doesn't show anything there. Should I just wedge in some foam behind the filter to keep it in place? Is there supposed to be a rubber piece at the back of the airbox to take up the space? Erg.

Can you upload some pics of your air box / filter gap
Some plastic parts , why ever, shrink over the decades and have to be re fit in position.

There is supposed to be a slot for the bottom to fit into.
Steve

A slot...? Hmmm ok I'll have to look again, but as far as I've seen the insides on this airbox have not been tampered with. It even came with a filter of the same size, albeit wrapped in washable foam instead of paper. I'll get some pics tomorrow though. I did notice on the parts page there is suppose to be an intake duct, looks kinds like a squashed pipe, which I'm missing. They're available on ebay though, so I'll add it to my list of things to grab when I have some money again.

I threw away the silencer years ago. I should have kept it. $$$ now.
Steve

Silencer? Is that all that thing does? I thought it was another bit controlling the airflow. So I probably don't need it?

I think on yours it's called the snorkle. It's to deaden the sound. Mine runs better without it.
Steve

Well considering I've been running without the seat, airbox cover, or filter, and I still can't hear anything from the airbox over the sound of the pipe... yeah I think I'm good without it.

All right, I saw the slot you were talking about, got the filter to seat down in it and when you screw the top on it locks the filter in place... just what I was expecting. Thanks for the tip!

Now another problem... after having the carbs apart on the bench all week, the O-rings on the plugs over the idle jets have shrunk, so they're falling back out of the holes. I've had them soaking in gasoline for the past hour thinking that would make them expand, but so far no luck. I'm not sure why they decided to shrink now, they've been sitting dry on the bench for the last three years and always fit snugly back into the holes.

Any thoughts on getting the O-rings to expand again? I'm anxious to get it back together because I found a lot more gunk and corrosion on the mixture screws after I got the caps off. One of the holes was completely plugged. With that all cleaned up, I want to fire up the bike again!

Do the bowls hold them in? Pic?
Steve

Well damn, I was typing up notes for the day earlier, and completely forgot to post the comment! Hold that thought...