Needles.

[Saul76]

Hi all!

I'm running a Keihin PJ carb - right now I feel like I have 1/4 - WOT throttle dialed in pretty good.

I have a ever so slight 'stumble' off idle.

Wondering if a needle change might help? Right now I'm running a R1469N needle in the middle position .. I have a DEG needle I can run - it's the same taper and length of the R1469N - but is a slightly leaner diameter ...

Opinions?

[86 Quad R]

what pilot you running? the off idle stumble is pilot issue not the needle. try workinhg with that and then go back and try dialing in the "D" series needle. :cool:

[Saul76]

Originally posted by 86 Quad R
what pilot you running? the off idle stumble is pilot issue not the needle. try workinhg with that and then go back and try dialing in the "D" series needle. :cool:

pilot is 48. Starts first kick cold or warm. Idles like a dream.

[thedeatons]

What is your entire engine setup?

James

[Saul76]

Originally posted by thedeatons
What is your entire engine setup?

James

250cc - any porting unknown
38mm PJ - 155 main, 48 pilot, r1469n needle middle clip
v-force 2 cage and reeds
k&n filter, sealed box
paul turner 89trx race pipe with fatboy silencer
NGK BR8ES plug gapped at 18
40:1 91octane mixed with Amsoil Interceptor.

14/38 gearing running 20x11x9 shoes.

[Saul76]

couple videos of it running on cold start - no warmup time. :ermm:

http://www.youtube.com/watch?v=mSASuQGLFNg

http://www.youtube.com/watch?v=9YJvJuemjtI

[86 Quad R]

i personally think you need some more realastate to be able to open it up in order to do a plug chop on her. it sounds to me that it was breaking up when reaching the mid range. ofcourse that could be due to the fact that it needed its throat cleared so to speak. the pj's are known for that.

my jetting is spot on but i too have to run through a couple or three gears before the throat is cleared after i let her warm up before riding. i too run a pj carb. :cool:

[Saul76]

I was able to open it up a little more on some kinda open road today.

Does it seem to pull the 14/38 gearing OK to you guys? I was told the 14/38 gearing would feel too tall on a fairly stock engine - but - it feels like it has a ton of pull to me.

http://www.youtube.com/watch?v=UBicTkXTQeI

[fulltiltrider]

sounds rich everywhere except the pilot to me. Im a big fan of the cej needle. If your machine idles well, its probably lean on the pilot. To idle well they need to be on the lean side, so when you hit the throttle it has a lean bog to it. As soon as you are past that though you can hear it breakup through the midrange.

[Saul76]

Originally posted by fulltiltrider
sounds rich everywhere except the pilot to me. Im a big fan of the cej needle. If your machine idles well, its probably lean on the pilot. To idle well they need to be on the lean side, so when you hit the throttle it has a lean bog to it. As soon as you are past that though you can hear it breakup through the midrange.

Well, again - running R1469N needle on the middle clip.

I'm pretty much as sea level.

Maybe it's a lil rich - but - sure doesn't 'feel' like it. When this things gets at 1/4 throttle and the pipe comes on it pulls very hard. There is absolutley no hesitation, stumble or blubber when the throttle is 1/4 to cracked WOT.

With winter on the way and everyday it's getting colder maybe it's for the best if I am a little rich then.

I still might try the DEG needle and see how it feels.

If a lean pilot is key to good idle then I'm guessing it'll stay a lil lean - I like my bikes to be able to idle good, clean and long if need be.

Thanks for your input.