I believe CCW makes the mixture richer while CW leans it.

i got a quick question i adjusted my idle mixture screw it solved most backfiring issues screwed screw in cw all the way and turned 2.5 times out ccw  but now my muffler wich is stock is whistling a tad should i be concerned about back pressure, compression ect.?? just bought 06 s40 and luvin it!!!!great bike

cool just didn't know thanx for the advise

thanx ptrider, i gotta question when the engine hasn't been ran for a while and is dead cold it stumbles rite after starting for a sec or 2,does that mean i have the a little mixture screw to rich?????this is in the mourning like 4 am temp bout 65 - 70 degrees, choke also makes it worse so thats why i'm thinkin to rich........................................ later on guys

yeah, usually anything over 3 turns out is too far and you should jet up.

There's so many jet/carb posts, you;ll find all the info there and then some.

Savage_Rob wrote on 09/19/05 at 11:37:33:

I agree

texsam wrote on 05/15/09 at 16:31:51:


Your local dealer should have them available.  If not then beat them thouroughly about the head and shoulders, then politely apologize for the slight over reaction to their lack of customer support and then let your fingers do the walking through the yellow pages to see if another local independent shop has a jet assortment.  If not available locally then go online; their are many parts suppliers listed in this tech section.  
I am away from home and will not be back for 2 weeks or so, otherwise I would just send you one.
Keep after it, someone has one.

**There is one other possible option depending on how far you are willing to go.  If you have a set of the tiny diamond files, usually 8-10 of assorted shapes included, can be had for very low $ at Harbor Freight or Northern Tool stores; one of the files in the set is round and very pointed and the tip of that file may be used to open the brass pilot jet hole.  It must be done gently and carefully lest you open it too far and find yourself in a too rich situation.  The brass is soft and files off very easily, so when inserting the point of the file into the end of the jet you just very lightly turn/twist the file with the fingers back and forth a couple of times; just enough to remove a hair of metal.  Install jet back in carb and test run & readjust the pilot screw.  (If you do this you might as well reset the pilot screw back to a 1.5 turn out position to give you a new starting point).
I find it a fun thing to do, just don't file the first time so much that you can really see metal on the point of the file, because if you can easily see the brass on the file the first time then you have likely gone too far already... I know about that one.  The first time I tried it I think I went up 2 or 3 jet sizes, but I was much to heavy handed and had turned the file probably 8-10 times until I could actually see that the hole was bigger.  That was a mistake.    Working gently and lightly will avoid that.  It is much better to go by touch, you can feel the file contact the brass hole and a couple of gentle turns is enough for each test step.
It is fun stuff.

let me ask one more question,when i bought the bike the brass plug was already removed and from day one i never needed to use choke not even when it's 45 - 50 degrees outside and the bike is dead cold when i adjusted the screw i tested it and it came out to 3 1/4 turns on the mixture screw best idle performance ect. then i turned it in to just 3 turns and it requires a little choke even in 80 degree weather sois that weiird to not use choke in those conditions (to rich) or is it weird to use a little choke 80 degree weather these are only on cold starts i mean dead cold starts