TOPIC:

I just purchased a 1981 kz550 that fires up real nice. But, she dies right away when the choke is taken off. She has air pods and a Kerker 4-into-1. So, I was thinking that the jets needed to be bumped up a few sizes. Am I even close to being right? And, what size should I bump them up to? I read that they were 92 or 94 for the mains and 32 for the idles.

Thank you for your help. I look forward to digging into the bike and through this website.

switch back to an air box pods with just be trouble i would also check the fuel lvls in ur bowls.
here is a link to the sfm thanks to loudhvx home.comcast.net/~loudgpz/GPZweb/Mnls/Kz...ase99924_1018_06.pdf

There may be some other issue. It won't run well with stock jetting, but you should be able to eek out some sort of idle.

If ytou are keeping the pods, after you fix any other basic problems (ignition, vac leaks, valve lash, etc.), I'd start with raising the needle to the 3rd notch from the top, 34 pilots, and 94 or 96 mains.

There are several manuals in my signature. Get them all.
Read the valve train warning before doing any engine work.
Check out my carb website for jetting and maintenance details.

Do you still have the airbox? If so, I recommend you get some nice, soft carb boots, new rubber holders for the head, clean the carbs carefully, and put the airbox back on.

These things are cold-blooded at best, and putting pods on makes them worse with stock jetting.

If you're keeping the pods, carefully (really careful) drill out the mixture screw covers, and you'll have to set them out farther than a turn-and-a-half, you'll want to get a set of Canadian jet needles, and bump them up to the middle clip, and you'll want to bump up the main jet to about 105. And after disturbing the needles/slides, you'll need a careful carb sync.

Good luck, and have fun !

GPzEric wrote: ...and you'll have to set them out farther than a turn-and-a-half,

That will make it leaner. Is that what you meant?

Since it's not a gpz, 105 will likely be too rich, especially at WOT where the throttle stop is set to overshoot the throat. Even 102 will be a little rich, but if he keeps stock pilots at 32, he may need to compensate on the main to run smooth.

If the bike only runs on choke the carbs are dirty and clogged. Clean the carbs pay special attention to the idle circuit. Your pilot jets will be clogged. Do not try and jet around a clogged carburetor, it will only frustrate you.

"That will make it leaner. Is that what you meant?"

No - on the TK22 carbs the mixture screws are not air screws, they are fuel screws. Turn them all the way in, and you turn off the fuel at idle.

On the several sets that I've done jetting on, the factory settings were about 1-1/4 to 1-1/2 turns out from the bottom, and I've richened up all of them a little bit.

had the same problem...my issue was as baldy110 has stated. my carbs wear gummed up especially my pilots from fine rust particles ..after complete cleaning and 2 new pilot jets i added inline fuel filters and was good to go.

Did you have to scrub & coat your tank too, or did you get lucky ?

GPzEric wrote: "That will make it leaner. Is that what you meant?"
No - on the TK22 carbs the mixture screws are not air screws, they are fuel screws. Turn them all the way in, and you turn off the fuel at idle.

I think you are confusing different carbs. The TK22 screws only ever have air flowing through them, no fuel. Look where they are located, they are on the air horn side of the slide. Fuel screws would be on the engine side.

But that aside, I have the ports mapped out if you'd like to verify.
home.comcast.net/~loudgpz/GPZweb/TK22mai...TK22portRouting.html
The pilot air at opening "G" goes directly to the air screw, before any fuel gets to it.

When I do jetting, I use an ega to set idle, then use a wideband to do the rest of the jetting. it's clear to see the effect of turning the screws out, it goes lean.

Not that it matters, but the screw is clearly listed as an air screw
"16014-1024 Screw, Air Adjusting USA".

And the FSM is also very clear on the subject: