Question about adjust idle mixture screws

[daverdfw]

So I have read all of the guides and DIY. But am still kinda confused. I am trying to adjust these to their correct spot. From what I read when you turn the screws in the idle should drop or engine would start to miss. When I do that the idle adjust jumps up. So I am confused as to where I would adjust the screw in and then back out a 1/4 or 1/2 of a turn. Thanks!

[jkv45]

Read through this section - http://faq.ninja250.org/wiki/Intake.

There's a lot of general carb info that may help you better understand what's doing what.

The page with idle mixture adjustment is here - http://faq.ninja250.org/wiki/How_do_...dle_mixture%3F

[Ghostt]

Your initial setting should be 3 full turns out from the bottom, remember just slightly tighten them, don't go all Conan on them.



Then warm it up, slowly turn 1 side pilot screw in until the rpms drop, then back out till RPM's peak (and no further)* Twist throttle...see how it reacts...tweak to taste.
Repeat on other side... test ride. You're looking for best throttle response and transition from just cracked to 1/4 throttle opening or so.*

Thats a quickie, 10 cent tutorial on setting pilot screws.**

[daverdfw]

so thats what is puzzling, When I turn the screws in the idle go UP not down.

[Ghostt]

Hmmmm, stupid question time,

Is the engine at operating temperature? Are you turning it the right way? Remember it's upside down so you must turn counter clockwise direction? Are all the parts in place, O-rings, and washers?

What happens when to bottom the screw out?

[SLOWn60]

Is your choke off?

[jkv45]

Originally Posted by daverdfw

so thats what is puzzling, When I turn the screws in the idle go UP not down.

That's not unusual if you are too rich (too many turns out).

Start at 2.5 turns out. Let the engine get fully warm. Add 1/4 turn out - does it increase or decrease the speed?

I like to find the highest idle speed, then go out (richer) by 1/8 to 1/4 turn. Then set the correct idle speed (up or down) with the idle speed screw.

[daverdfw]

Originally Posted by jkv45

That's not unusual if you are too rich (too many turns out).

Start at 2.5 turns out. Let the engine get fully warm. Add 1/4 turn out - does it increase or decrease the speed?

I like to find the highest idle speed, then go out (richer) by 1/8 to 1/4 turn. Then set the correct idle speed (up or down) with the idle speed screw.

yeah I think the issue might be its not warm enough. I am building this for the track, the choke has been removed and replaced with safety wire. I will just set it at 2.5 and then once I get to ride it at the track and its warm I will adjust it.

[daverdfw]

Originally Posted by Ghostt

Hmmmm, stupid question time,

Is the engine at operating temperature? Are you turning it the right way? Remember it's upside down so you must turn counter clockwise direction? Are all the parts in place, O-rings, and washers?

What happens when to bottom the screw out?

if i bottom the screw out on one of the carbs the idle goes up and it keeps running

[Ghostt]

If the bike is track only use, then don't worry about it, anything past 1/4 the pilot circuit isn't doing much, by 1/2 it's not doing anything, it's the mains, and needles job.



Last stupid question, you sure the carburetors are 100% functional? Maybe @ducatiman may have an idea?

[daverdfw]

Originally Posted by Ghostt

If the bike is track only use, then don't worry about it, anything past 1/4 the pilot circuit isn't doing much, by 1/2 it's not doing anything, it's the mains, and needles job.

yeah that's kinda what I was thinking. This bike has a full M4 system, K&N filter KLEEN removed. I went with a Factory Pro 3.0 kit. Using 112 mains 40 pilot and clip in 3rd slot.

[Ghostt]

Then don't worry about getting the idle mixture screws adjusted set to 2 1/2~3 turns out, after all its a track bike, be more concerned about dialing in the mains/needles.

[daverdfw]

Originally Posted by Ghostt

Then don't worry about getting the idle mixture screws adjusted set to 2 1/2~3 turns out, after all its a track bike, be more concerned about dialing in the mains/needles.

makes sense. Thanks for the advice!

[Ghostt]

If you have access to an exhaust gas analyzer then your set, otherwise seek advice from fellow forum racing members, whom should have insight about jetting for track use.

[Ghostt]

SIDENOTE:

I know NewGen carburetors are set-up different from Kawasaki, with two different size needles, and other such changes.

Unfortunately that's all I know about NewGen, hopefully someone will clarify the differences between them.