Air/idle adjustment screws

[buzzlitebeer]

Can anyone point me in the right direction? I have a 1990 Katana that has been sitting for a long time. I have drained and cleaned the gas tank. I took the carbs apart and cleaned/ inspected them, and put them back together. The next step that I was going to do is give it an initial set up to start the bike and then fine tune it. I will sync the carbs, and can find info on that, but I can not find any info on setting the air/idle adjustment screws, or how to set them when its running. I thank anyone who can help.

[Kfreak]

What do you have? 600 or a 750 ? You can set them up with the bike running with a color tune. If it's a 600 go 2 turns out on the screws. If it's a 750 go 2.5 out. It's just a starting point.

[arsenic]

WRONG!!!
600 or 750 do NOT make any difference, thats why the 600 (depending on year) is 31-33mm, the 750 is 36mm. 2.5 whatever you have

[buzzlitebeer]

Katanafreak93, you said ~2 turns for an initial setup. That should be a good starting point. Thanks for the help.

[arsenic]

no, 2.5 turns is perfect. It's not a starting point, thats were they should be

[Kfreak]

WRONG!!!
600 or 750 do NOT make any difference, thats why the 600 (depending on year) is 31-33mm, the 750 is 36mm. 2.5 whatever you have

You kill me! I knew you were going to pop in sooner or later. Shall we get into atmospheric pressure an altitude? Maybe that is one can of worms that we not need to open. Go with the 2.5. If you can use a Colortune, do it. No one will argue with you after that.

Don't mind Arsenic, he knows what he is talking about.

[buzzlitebeer]

Arsenic, you said that 2.5 turns is perfect. Could you give me a little advice on carb tuning? I have one carb that is not matched with the others ( #3 ). I find it impossible to correct by adjusting the idle screw between carbs 3 and 4. My next step would seem to be the air/idle screw, but I can not reach it without removing the carbs.
I guess my question to you is: What should my next step be?

[arsenic]

did you try to sync them? BTW a/f screws have NOTHING to do with that That's NOT an idle screw, that's a sync screw, you can't go messing with that without a manometer and expect to fix it. You're problem is simple, the carbs are out of sync (more so now that you messed with that screw) You NEED to have the carbs synced, call around get quotes.

[buzzlitebeer]

I can appreciate your honesty, but with all due respect, i have done nothing more than put the sync gauge on and read them. That is how I know one of them is off. I will admit that I do not have any experience with this type of engine, but I do have some experience with automotive engines and dual carbs that require syncing. As I have stated before, I would gladly accept any help you can offer, but I do not see "call around to get quotes" as help. Please correct me if I am wrong, but the "sync" screws do nothing more that adjust each carbs individual idle. So syncing these together is nothing more than making sure that carbs 1 & 2 match and 3 & 4 match. If all of them match on the gauges.. great. If they don't match or can not be adjusted to match.. Now here's where I was earlier.. What should "I" do next?

[kevin2502000]

Are you asking how to synch them?

[md86]

[arsenic]

the way you sync carbs is there are 3 screws. you match 1 to 2, 3 to 4, and the middle screw adjusts 1&2 to 3&4

I can appreciate your honesty, but with all due respect, i have done nothing more than put the sync gauge on and read them. That is how I know one of them is off. I will admit that I do not have any experience with this type of engine, but I do have some experience with automotive engines and dual carbs that require syncing. As I have stated before, I would gladly accept any help you can offer, but I do not see "call around to get quotes" as help. Please correct me if I am wrong, but the "sync" screws do nothing more that adjust each carbs individual idle. So syncing these together is nothing more than making sure that carbs 1 & 2 match and 3 & 4 match. If all of them match on the gauges.. great. If they don't match or can not be adjusted to match.. Now here's where I was earlier.. What should "I" do next?

NO, they do NOT adjust each carbs "idle" they adjust the vacuum level in each carb, which means you are balancing the vacuum level in each carb so that the whole bank is the same. NEXT is a valve adjustment, the valve clearance is what determines the vacuum levels.

[md86]

But the carb synch comes AFTER the valve adjustment , just so we're clear .....

[arsenic]

correct

[buzzlitebeer]

Now this sounds like good helpful information. Thank you all for the input. I now have the correct steps to take in the correct order, we will see how things turn out. Again thanks