This post is gonna make me look stupid, but, can someone explain.....

how to properly use the fuel/air screw that the Kouba goes onto? I have never adjusted it in the past year and am gonna get a Kouba due to everyone's raving about it. What in the hell do I have to adjust? I assume that I use the screw to change the mixture according to altitude, temperature, and humidity. but, how do I know when it needs a little tweaking? Please let me know, I really appreciate it.



Your engine will let you know when an adjustment is needed...It could be a rough idle, a decelleration popping (lean Condition), or a cold weather starting problem (Rich Condition), all of these issues are centered around the fuel screw located on the bottom of the carb. The Kouba Tool makes it a snap to adjust, even with the bike running (Which makes it invalueable for rough idle situations. It's easy to reach, no more burning the hands. The T-Handle makes a great reference point when counting the number of turns.

Good Luck

Bonzai :)

thanks kazi, I appreciate your input.



I will be the first to tell you that is not a stupid question. I too was wondering what all the hype about this Kouba thing was. I for one haven't had any of the problems associated with needing one after finding the correct jetting. That itself made a HUGE difference. I know the airscrew can make subtle changes for some problems, but I've never messed with it. Probably due to a lack of knowledge on my part. Who knows, maybe I just THINK my bike is jetted right. Anyway, I don't think any question in TT is a dumb one. That's why we all communicate in here.

Originally posted by WRoost:

don't think any question in TT is a dumb one. That's why we all communicate in here.

Think of this site as your big brother. You could ask him anything....right??!! :)


:) The ONLY Dumb question the one you DONT ask ! If you need an answer ask away, the quest for knowledge involves asking questions, if you dont ask you wont learn :D

This site is great I am quickly becoming addicted to it cause I wouldn't have asked the question but I definately wanted to know.

Used to be I didn't get online for months at a time now I gotta check out all the dialogue, just about every other day or so.

That certainly isnt' a dumb question if you don't live in the mountains. Here in Colorado we ride from 7000 feet to 14000 feet on one tank of gas and the screw needs constant adjustment to avoid that annoying popping.

In flatter country, you probably don't have to adjust that little sucker too often.


go half a turn forward and back and try snap tests in first gear. if you're on really high gearing like 14/52 try it in second. ride along at tickover and just blip it to try a little "pop wheelie".

presuming you've done the BK or Taffy mod first you will start to get valid results.

the idea is to see which gives you the sharpest response. if you genuinly feel you need two full turns the chances are that you have a slightly lean low speed mixture.

this can be caused by the PC (pilot circuit) ratio of the PJ/PAJ being out. lean =too small PJ or too large PAJ. it's been tested by me that the vast majority are rich here so we can say that it's too large PJ/too small PAJ.

the last one to effect this lean condition is the needle. if this is lean you're more likely to stall or find it hard to start even.

if and when you've got your low speed jetting right you should come back to 1 1/2 turns out (from closed).


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