Quick little carb question...

[maverick31210]

I've read that these things come a little lean from factory because of emissions.

I have a CA bike, so I know I'll have to pull the idle mixture screw plugs before I can adjust anything...no big deal at all.

My question is, what do I do to a little more low to mid? Assuming there is even anything there to work with at all.

Thanks fellas!

[csmith12]

Yes, lean from factory.

Mods for cheap;

Adjust mix screws 2.5 turns to start and go from there
Shim needles (search here, many have done it #4 washers from radio shack are your minimal investment)

[maverick31210]

Originally Posted by csmith12

Yes, lean from factory.

Mods for cheap;

Adjust mix screws 2.5 turns to start and go from there
Shim needles (search here, many have done it #4 washers from radio shack are your minimal investment)

Do I have to do both at once or just start with the screws and see how I like that? Stupid question but clockwise or counter?

[csmith12]

No, you can do them in any order but since you got the carbs off, might as well save you some work ya know.

Turn mix screws all the way in (right) until closed. Open them back up 2.5 turns (left) and adjust up or down as needed.

[maverick31210]

Originally Posted by csmith12

No, you can do them in any order but since you got the carbs off, might as well save you some work ya know.

Turn mix screws all the way in (right) until closed. Open them back up 2.5 turns (left) and adjust up or down as needed.

Once I pull those plugs out, I should be able to adjust the carbs on the bike with a stubby little screwdriver right?

[csmith12]

Originally Posted by maverick31210

Once I pull those plugs out, I should be able to adjust the carbs on the bike with a stubby little screwdriver right?

Yep, that is what I do.

[maverick31210]

Originally Posted by csmith12

Yep, that is what I do.

Right on! Just have to yank them to pull those plugs out.

[SLOWn60]

Originally Posted by maverick31210

Right on! Just have to yank them to pull those plugs out.

...that's the hard part! LOL!

[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.**

The #4 washers work nicely, start with one, then try two under each needle, after you have the idle mixture screws adjusted.

http://faq.ninja250.org/wiki/Washers_for_carb_needles

The picture below shows what effects what, as you can see idle mixture screws are good to almost 1/2 throttle position.

Link to original page on YouTube.

[maverick31210]

Originally Posted by Ghostt

The #4 washers work nicely, start with one, then try two under each needle, after you have the idle mixture screws adjusted.

http://faq.ninja250.org/wiki/Washers_for_carb_needles

The picture below shows what effects what, as you can see idle mixture screws are good to almost 1/2 throttle position.

Link to original page on YouTube.

Much thanks for that! That will be very helpful.

I'll start with the screws first and go from there. What can I expect to get out of that? I know individual mileage will vary...

Originally Posted by SLOWn60

...that's the hard part! LOL!

LOL, is it that bad? I figured I could drop some screws in there and pull the whole thing out? Maybe drill lightly and use a pick? Suggestions?

[Ghostt]

With my current setup I'm avg. About 47 mpg.

Gearing +1/-2
Stock jets, 2 washers per needle,

[maverick31210]

Originally Posted by Ghostt

With my current setup I'm avg. About 47 mpg.

Gearing +1/-2
Stock jets, 2 washers per needle,

What if I'm not so much concerned about mileage and more about a little more pickup in the lower revs? Gearing is stock FWIW.

[dcj13]

Originally Posted by Ghostt

With my current setup I'm avg. About 47 mpg.

Gearing +1/-2
Stock jets, 2 washers per needle,

You must have a heavy hand or a really short commute. I was running
+1/-1 sprockets and stock exhaust and carb settings (never tampered with) on my '03 and typically got 59 mpg (not being particularly gentle with the throttle).

Originally Posted by maverick31210

What if I'm not so much concerned about mileage and more about a little more pickup in the lower revs? Gearing is stock FWIW.

Get a 13 tooth front sprocket, maybe.

[Ghostt]

Originally Posted by dcj13

You must have a heavy hand or a really short commute. I was running
+1/-1 sprockets and stock exhaust and carb settings (never tampered with) on my '03 and typically got 59 mpg (not being particularly gentle with the throttle).



Get a 13 tooth front sprocket, maybe.

Yes to both, my commute is about 11 miles, and on country roads, on the long interstate I get about 55mpg.

If your looking for more acceleration, go with 13 teeth, it's a noticeable difference for sure.

[SLOWn60]

An observation regarding the 13 tooth front sprocket:

I run a 13:47. My stock was 14/45 (2012).
I have an adjustable ride height shock and set my swingarm at about 12.5 degrees. My chain, when under tension, just kisses the swingarm chain guard.
In plain english: if you drop to a 13 front sprocket, check to make sure the chain is not sawing into the chain guard. Going up a tooth or two on the rear sprocket will offset the drop in height that results from the smaller diameter front sprocket. It may not be an issue but it was something I noticed when I set up mine.

[Rifleman]

carbs are voodoo, like cooking with Julia Child... If you don't have a 1/2 cup of Bordeaux 1 cup of Pinot Noir will do.

Electronic Fuel injection is actually science

[spooph]

Don't mix up the needles from the carbs, they are different as the stock exhaust has cylinder 1 tuned for power and cylinder 2 tuned for torque. For more low-end pickup, and I don't think anybody else has ever tried this yet, but you could just adjust the cylinder 2 carb, and then synch them again....

If however you are going to swap out, or have swapped out the exhaust, that is now negated and the jet kit from DynoJet is awesome as it includes needles with a completely different profile providing a much more linear response.

washers a good place to start.

This is also spectacular for adjusting the idle mix screws while on the bike:
http://www.motionpro.com/motorcycle/partno/08-0229/

[choneofakind]

Spooph, I was under the impression that the pregen needles were the same on each side, where the newgen needles are different on each side, like you suggest?

[spooph]

Originally Posted by choneofakind

Spooph, I was under the impression that the pregen needles were the same on each side, where the newgen needles are different on each side, like you suggest?

werps, thought it was a new gen. I don't know specifically for the pre-gen. Woops! My bad!