d rockwell

~SPONSOR~
Nov 10, 2001
82
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I noticed on the jet needles tips by Canadian Dave diameters larger then 2.745 are omitted, but Kawasaki sells 2 needles with larger diameter; R1175K and R1176K. Aren't these needles leaner because the diameter is larger? I'm presently running a stock R1174K. If I'm rich in the mid range at 10,000 feet wouldn't I want to use one of these needles or would I want to go longer length with a R1174L? My bike is a '96 200KDX shaved head, but premium gas, air box mod, FMF K-35 torque pipe, Boysen 607 reeds. I thought with Boysen reeds it was leaner settings ie pilot, main. The diameter most effects 1/8 to1/4 throttle and transition to the main circuit. Is it really more gas thats making the throttle response snap? Confused.......................
 

canyncarvr

~SPONSOR~
Oct 14, 1999
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A needle with a larger diameter is leaner than one with a smaller diameter.... all other things being equal.

If you've read CDave's needle decoder, then you've seen the throttle opening chart and know that straight diameter is out of the picture by 1/2 throttle...as you stated.

That said, your reference to '..rich in the mid range' is going to be a taper issue (from the same chart) and may well be changed with the clip ('rasing' the clip (lowering the needle) making the circuit leaner).

The 'L' needle is proprietary kawi...it falls between the Keihin 'F' and 'G', or 38.60mm and 39.95mm respectively. That gives you an L1 difference of 1.35mm, while a clip change on a needle gets you .9mm.

Unless you're out of whack on the 'K' (at one end or the other) there isn't any big reason to change to an 'L' unless you are trying to tune between the clips and don't want to mess with needle spacers.

I don't get this:
Is it really more gas thats making the throttle response snap?

Is it throttle response that you have a problem with? Adjust the AS for best throttle response, that 'defined' in this case to mean instant response in 2nd gear from a walking speed with a quick wrist flick to 1/2 throttle or so. Preferably under a bit of load, say a slight uphill.

From the tenor of your question it seems you've done your research and have a pretty good handle on what it is your after. A good bit of what's said above you likely already know. If it all danced around the answer to your question...sorry about that. I'm not sure what you're after with that last sentence.

Oh...and, yes. Boyesen as stated would call for slightly more lean in the pilot and main. Usually. Considering jetting was spot-on to start with.

If you haven't used the AS as a tuning device, give it a shot. Granted, an RB carb seems to make the AS a bit more important (mine is), but while 'set it and forget it' is the mantra of some regarding the AS, I think they are missing out on some primo performance gains. 1/16 of a turn can make a huge difference in the pull I get out of 3rd gear on a fair uphill and in throttle response (off idle) in lower gears.

Good luck.
 

d rockwell

~SPONSOR~
Nov 10, 2001
82
0
CanyonCarvr Thanks for the quick reply. I did forget the straight section of the needle is out of the picture at the midrange and that the air screw not only effects response at slower speeds but pulling a hill in third gear! I guess my real question is looking at the Kawasaki needles '95-'02 200KDX The only thing that changes is the straight section diameter from the R1172K at 2.725 to the R1176K at 2.765, which is omitted as not applicable to KDX owners? I'm assuming the R1175K and R1176K are the leanest, are they too lean? When I ride in Silverton Colorado we camp at 10,000 and ride all day above this altitude. If I'm riding on the #1 clip at 7000 to 8000, wouldn't I want to consider a little leaner needle for Silverton? I usually run a 138 or 140 main. I've been playing around with jetting a long time but mostly with clip position pilot and main. I'm beginning to realize how important the air screw is and it's easy to adjust! I know when everything is right the bike really comes alive. Startin to get it.... Dave
 

canyncarvr

~SPONSOR~
Oct 14, 1999
4,005
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Don't know about the quick part. I get more 'no notices' than 'notices' in email when a thread is posted to. Thought that got better for awhile..now it's iffy. Didn't know you'd posted back to this thread.......

Anyway, I don't know if the term 'leanest' applies to the 75-76K. I'm not looking at a kawi chart. Certainly they are more lean than OEM, and if kawi says they are not applicable to the kdx, they are taking 'normal' jetting reqs into account. I would say 'over 10k ft. el.' isn't going to fit into the normal category.

You've looked at the correction table on CDave's site?

http://justkdx.dirtrider.net/

<tech tips> <carb tuning>

Changing from 8k ft to 10k ft gives you a relative correction factor of .985 or so.

If you want to change the overall A/F ratio, change the main and pilot. The needle is going to have more to do with progression between the two.

138-140 doesn't seem right to me. If I can run a 150 @ 7k ft. with an 1174L-5 and be right on the skinny edge of things, then your running a 140 and over 3 clips leaner seems scarey to me. You ARE running a KG35, which takes a leaner set than a KG30 (that I had with my listed jetset), still...seems too lean to me.

Clip positions are numbered from the blunt end, right. Your being on #1 means your needle is the LONGEST it can be?

IF your jetting is correct (I don't mean you listed the numbers correctly...I mean the numbers listed are verified through plug/response tests to be good) as you listed for 7-8k ft., then you would indeed want to be a bit leaner for above 10k. Using CDave's correction table (for the main) you'd change from a 140 to a 138.

In CDave's example, he's going from 2200 to 9600 ft. That's a lot bigger relative change than what you're dealing with. For the el. change you're talking about, I'd be sticking with the AS.

Something just don't seem right, though. I don't see a pilot #. Exaggerated (I hope) to make the point, but if you're running a 45-138-1174K/1, I think you're out of whack!! Something along the line of overcompensating on the over 1/4 throttle side to make up for a pilot that's too big!

I'm not the driver here...but I'd like to see a start from the basics. I'd like to see a plug out of your bike after a WOT plug chop the way it's set right now. I'll bet it's one white sunnuvagun! You'd have to pay me enough money to big-bore kit my bike before I'd even TRY a WOT the way you're set right now. ;)

Simply put, dropping the main one will put you in the ball part...(starting from the correct point in the first place!!)
I know when everything is right the bike really comes alive.

Amen!
 

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