200 needle starting point

[ia426]

I've been reading the 200 jetting database trying to decide where to start with the needle on my 200.

 

Here's where I'm at;

 

Year: 2003

Model (E,W,XC,M): MXC

Carb size (38 or 36mm): 38

Elevation: 800ft

Slide: 6.5, stock

Main jet: 175

Pilot Jet: 42

Air screw (turns out): 2.0

Needle model/Clip position: NOZE, 4th (second from top)

Reeds: V-Force

Pipe/silencer:  FMF/FMF I'll post a pic of the pipe at some point, it doesn't fit quite right.  SX pipe?  It was on the bike when I got it.

Head mod: stock

Other mods: mildly ported jug, basically just cleaned up, PV in the Langston setting

Type of fuel: 91 pump, Used to run 87 when it was easier to find non-ethanol 87.  Lucas 32:1  Just started using Lucas. 

Where in the powerband do you ride (Lugger - for technical stuff, or wide open - desert / MX):a mix, lug when it's tight and open 'er up when it widens. I generally stay just off the pipe though, riding in the meat of the power.  Yep, me too.

Degree of satisfaction: ambivalent

And finally: how much spooge;  Very tolerable, just barely runs down the cap now. Plug is black, very black. 

 

Started out a couple weeks ago feeling like it was rich everywhere.  Smaller pilot, main, lowered the needle, much more responsive and luggable than it was.  Runs fine, but based on the plug there's at least as much more to get as I already have.  Got jets from a local dealership.  They came out of their generic jet assortment.  Wonder if I should get OEM Keihin jets so know I'm dealing with a known quantity.

 

What I'm looking for is maybe an overall recommendation as a starting point.   I'm thinking about getting 40 pilot, DDL needle, 180-182 on the main

Edited April 27, 2014 by ia426

[jersey_devil]

The rich issue your having is the needle itself.

There are many excellent needle choices to choose from. The DDK and DCK work together as 1/2 clip twins and are an old standard.

Suzuki NEDG is another and of course JD jetting kits. There are more choices but I'll stop here.

While generic jets work, it's adviseable to use genuine Keihin brass so your working with a known "standard". Generic jets are known to deviate some in their flow rate. Genuine Keihin have that fancy K that looks like a star stamped on them.

[kbob999]

I'd also go to 40:1 or 50:1 on your oil, using a full synthetic. This will richer the fuel and clean up the plug.

[ia426]

jersey_devil, thanks for your input. I've read a lot of your posts in the 200 jetting database.

I ordered 40 & 42 OEM pilots, DDK & DCK needles, and 175, 180, & 182 OEM mains. Have of course the original 45 pilot and 178 main. We'll see what I can make with those parts.

kbob999, Less oil may be where I go eventually, but I'm going to see what I can do with 32:1 first. I'm a believer that more oil = more power and I've never blown one up @32:1.

Also last night I talked with a local shop about modding the head. They're a couple weeks out. My plan is to get the jetting close with the parts I've just ordered(to the rich side) and then see just how much the head mod cleans it up. Sort of a learning experience.

Also ordered a new choke plunger. Bent mine a while back in a wreck. Straightened it out and it's seemed fine but it's always been in the back of my head whether it sealed properly after that.

Edited April 30, 2014 by ia426

[Larry63r]

2003 200 mxc/exc jetting chart

[ia426]

So tonight I switched stuff around;

 

Pilot: 40

 

Air Screw 1 turn out

 

DDK needle 3rd clip position

 

180 main

 

New choke plunger, going to be so nice to have a working detent on the choke again.

 

Too dark to ride it by the time I got done.  The local PD sort of looks the other way when I ride on the street but not at 10pm w/no lights.

 

What I was able to do was warm it up on the stand.  Seems like it starts better.   Wacking the throttle from an idle creates a lean bog.   My take is that A. you'll never do that riding and B. with no accelerator pump if you jet it rich enough to cover that hole it will be rich under normal conditions.

 

Anyone have an opinion on that?^^^^

[jersey_devil]

You probably need a 45 pj. The single taper needles have a rather long straight length, almost to 1/4 throttle before the taper begins. The engine is "wanting" more fuel as the throttle opens, certainly by 1/8 throttle. The long straight length doesn't allow additional fuel, so this is where needle starting diameter and the pj comes in to compensate. Multi-taper needles, the taper starts just before 1/8 throttle and is more "forgiving" so to speak but slightly harder to tune and understand. The OEM NOZx series is a multi-taper, but the taper begins the moment the slide moves. In other words there is no significant straight length. The theory of an immediate taper is good, but in practice doesn't lend itself to less aggressive riders. It's good for MX but tends to load up if your a slower technical trail rider.

 

There are a few methods for setting the a/s. The one I like best and suggest is the "wick the throttle" method. With a hot engine while on the stand, wick the throttle. If there is a hesitation immediately off idle, turn the a/s richer by 1/8 turn and repeat the test. Wait for about 20 seconds between tests. You want the engine to respond immediately with no hesitation. If the a/s ends up less than 1 turn out, increase the pj a size and repeat the test. It is very important to have enough fuel right off idle for proper and strong engine response right off idle. It also helps with the lean surging and when you chop the throttle after a high speed run.  

[ia426]

Rode today. Ended up 42 pilot. 182 main. Raised the needle a notch. Air screw's around 1 1/2 out.

Plug's lighter than I would like, but I got into some sand that was third gear WOT to where it was struggling to gain rpm. I figure if it was going to seize it would have then.

Going to leave it where it is for now. The air was pretty good today. It's supposed to get hot and humid so it should fatten up.

My throttle tube is super sloppy. I marked on the grip with a Sharpie 1/4, 1/2 throttle etc. Need to get a new tube if I'm going to try to use that. Realized riding that the slop in the tube makes the marks move around too much to be real useful.