Need help with needle or ????

Questions and Answers about the best carb and Head mods available for the KDX.
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canuckhybrid125
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Need help with needle or ????

Post by canuckhybrid125 »

Guys I have been fooling around with my jetting after rebuild,I have all RB mods plus the 200 is bored to 220.I am getting alot of spooge.Here is what the bike is running on now,im at sea level around 60-80F degrees.Main 150 pilot 38 needle at second slot now which I have'nt tried yet.I just had a look at the needle and it says BEL any help would be great.
Thanks
PS I dont know where or how to buy different needles.
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Post by scheckaet »

Some spooge is normal.
local dealer should be able to hook you up with needles.
Have you jetted the bike properly? check the jetting section and how to jet.
Have you repacked your silencer recently?
38 on the pilot sounds a bit lean but I'm no expert with 220. Ask RBD, might be able to tell you what to start with.
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Post by Indawoods »

Didn't Ron send you a DEK and a CEK with the carb mod? BEL is way off....

With a 200 bored to a 220, the porting will be off.....
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Post by canuckhybrid125 »

This is running down my pipe type spooge,Ron said try 150 main and 40 pilot,which I dont have yet.But the bike is smoking like a fog machine right now at 1/4 and half throttle.Could it be because of the fresh rebuild?
Last edited by canuckhybrid125 on 09:09 pm May 13 2010, edited 1 time in total.
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Post by canuckhybrid125 »

>|<>QBB<
Indawoods wrote:Didn't Ron send you a DEK and a CEK with the carb mod? BEL is way off....

With a 200 bored to a 220, the porting will be off.....
Dont know this is the needle that came withnthe bike.
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Post by scheckaet »

then it's not. Ron didn't send you any other needle and / or jetting recommendation?
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Post by Julien D »

Did YOU have the RB mods done, or did the PO tell you that HE did? I would question this.
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Post by canuckhybrid125 »

>|QBB<[/url]
juliend wrote:Did YOU have the RB mods done, or did the PO tell you that HE did? I would question this.
PO had it done,it has the rb fuel screw divider plate and slide,plus PO told me the head was done.
[img][img]http://i230.photobucket.com/albums/ee35 ... /005-3.jpg[/img][/img]
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Post by Mr. Wibbens »

Whats going on with your vent hoses?
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Post by canuckhybrid125 »

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Mr. Wibbens wrote:Whats going on with your vent hoses?
Its one of those vent hose filter kits which relocates the vent hose into the air box that used to be on the bike.
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Post by canuckhybrid125 »

Got a CEK needle today seems to be better when warmed up.But I have to turn the rb fuel screw out at least 1 3/4 turns or else the engine will stall.When I had the fuel scew out 7/8 to 1 turn the plug was soaked with fuel.
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Post by Indawoods »

That's jetting....
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Post by canuckhybrid125 »

>|<>QBB<
Indawoods wrote:That's jetting....
Inda your not helping me out with these short answers lol.I have a 150main 38 pilot ,do I have to go up or down.I cant get a hand on this jetting stuff.Seems easy on paper.
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Post by Indawoods »

A correctly jetted carb makes a tremendous difference in the torque, midrange pull, top-end pull, and over-rev of your engine. If you have

never jetted your bike correctly, you will almost certainly gain some performance at some point in the bike's powerband. A cleanly jetted pilot

circuit can be the difference between having to clutch the bike out of a turn or not. The needle can make all the difference in the world for the

power of the machine in most situations, as it controls the throttle range that most riders spend most of their time using. A correctly sized main jet

could mean the difference between being able to rev out high enough to not have to shift one more time at the end of the straight, or the power

falling flat on top and requiring you to make that extra shift.

Are you fouling plugs? Many people will tell you all sorts of band-aid fixes,

from running less oil, to running a hotter plug. Both are incorrect fixes for plug fouling. It's all in the jetting.


The only way to know what jetting changes you will need is by trial-and-error. No one can give you jetting specs, because every bike is different,

every rider has a different style, and jetting is totally weather dependent. Unless the person telling you what jets to use is riding an identical bike,

on the exact same track, at the same time, his recommendations are meaningless.

Jetting is fairly simple, and is a useful skill to learn if you ride a two-stroke and want it to perform at it's best.

It's very important that you start with the pilot circuit. The reason is simple. The pilot circuit affects the entire throttle range. When you are at

full throttle, the main jet is the primary fuel metering device, but the pilot is still delivering fuel as well, adding to the total amount of fuel that your

engine is receiving.

Before you start to rejet your bike, you need a clean air filter, a fresh

plug (actually you need several plugs to do plug-chop tests for the main jet), and fresh fuel. One important detail: Make sure the engine is in good

mechanical condition. If your engine has a worn top-end, fix it first. Trying to jet a worn out engine is a waste of time. The same goes for

reeds that don't seal properly, and a silencer that needs re-packing. Worn reeds will mimic rich jetting, and worn rings will mimic lean jetting.

Before you start the jet testing, install a fresh plug. Set the float level to the proper specs, an incorrect float height will affect your jetting all

across the throttle range.

Warm the bike completely, and shut it off.

As already stated, start with the pilot circuit. Turn the airscrew all the way in, then turn it out 1.5 turns to start. Start the engine, and turn the idle

screw in until you get a slightly fast idle, or hold the throttle just barely cracked, to keep the engine idleing. Turn the airscrew slowly in, and then

out, until you find the point where the idle is fastest. Stop there. Do not open the screw any farther, or your throttle response will be flat and

mushy, and the bike may even bog. This is only the starting point, we will still have to tune the airscrew for the best response.

Now is the time to determine if you have the correct pilot installed in your carb. The airscrew position determines this for you, making it very

simple. If your airscrew is less than 1 turn from closed, you need a larger pilot jet. If it is more than 2.5 turns from closed, you need a smaller pilot jet.

Once you have determined (and installed it if it's necessary to change it) the correct pilot jet size, and tuned the airscrew for the fastest idle, it's

time to tune the airscrew for the best throttle response. Again, make sure the bike is at full operating temperature. Set the idle back down (the bike

should still idle, despite what you read in the Moto Tabloids), and ride the bike, using closed-to-1/4 throttle transitions. Turn the airscrew slightly in

either direction until you find the point that gives you the best response when cracking the throttle open. Most bikes are sensitive to changes as

small as 1/8 of a turn.

The airscrew is not a set-it-and-leave-it adjustment. You have to

constantly re-adjust the airscrew to compensate for changing outdoor temps and humidity. An airscrew setting that is perfect in the cool

morning air will likely be too rich in the heat of the mid-day.

Now, it's time to work on the needle. Mark the throttle grip at 1/4 and 3/4

openings. Ride the bike between these two marks. If the bike bogs for a second before responding to throttle, lower the clip (raising the needle) a

notch at a time until the engine picks up smoothly. If the bike sputters or sounds rough when giving it throttle, raise the clip (lowering the needle)

until it runs cleanly. There isn't really any way to test the needle other than by feel, but it's usually quite obvious when it's right or wrong.

Last is the main jet. The main jet affects from 1/2 to full throttle. The easiest way to test it is to do a throttle-chop test. With the bike fully

warmed up, find a long straight, and install a fresh plug. Start the engine, and do a full-throttle run down the straight, through all gears. As soon as

the bike tops out, pull the clutch in, and kill the engine, coasting to a stop. Remove the plug, and look deep down inside the threads, at the base of

the insulator. If it is white or gray, the main is too lean. If it is dark brown or black, the main is too rich. The correct color is a medium-dark mocha

brown or tan.

Once you have a little bit of experience with jetting changes, and you

start to learn the difference in feel between "rich" and "lean", you'll begin to learn, just from the sound of the exhaust and the feel of the power, not

only if the bike is running rich or lean, but even which one of the carb circuits is the culprit.

The slide is also a tuning variable for jetting, but slides are very expensive, and few bikes need different slides, so we won't go into that
here.
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
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Post by canuckhybrid125 »

>|<>QBB<
Indawoods wrote:A correctly jetted carb makes a tremendous difference in the torque, midrange pull, top-end pull, and over-rev of your engine. If you have

never jetted your bike correctly, you will almost certainly gain some performance at some point in the bike's powerband. A cleanly jetted pilot

circuit can be the difference between having to clutch the bike out of a turn or not. The needle can make all the difference in the world for the

power of the machine in most situations, as it controls the throttle range that most riders spend most of their time using. A correctly sized main jet

could mean the difference between being able to rev out high enough to not have to shift one more time at the end of the straight, or the power

falling flat on top and requiring you to make that extra shift.

Are you fouling plugs? Many people will tell you all sorts of band-aid fixes,

from running less oil, to running a hotter plug. Both are incorrect fixes for plug fouling. It's all in the jetting.


The only way to know what jetting changes you will need is by trial-and-error. No one can give you jetting specs, because every bike is different,

every rider has a different style, and jetting is totally weather dependent. Unless the person telling you what jets to use is riding an identical bike,

on the exact same track, at the same time, his recommendations are meaningless.

Jetting is fairly simple, and is a useful skill to learn if you ride a two-stroke and want it to perform at it's best.

It's very important that you start with the pilot circuit. The reason is simple. The pilot circuit affects the entire throttle range. When you are at

full throttle, the main jet is the primary fuel metering device, but the pilot is still delivering fuel as well, adding to the total amount of fuel that your

engine is receiving.

Before you start to rejet your bike, you need a clean air filter, a fresh

plug (actually you need several plugs to do plug-chop tests for the main jet), and fresh fuel. One important detail: Make sure the engine is in good

mechanical condition. If your engine has a worn top-end, fix it first. Trying to jet a worn out engine is a waste of time. The same goes for

reeds that don't seal properly, and a silencer that needs re-packing. Worn reeds will mimic rich jetting, and worn rings will mimic lean jetting.

Before you start the jet testing, install a fresh plug. Set the float level to the proper specs, an incorrect float height will affect your jetting all

across the throttle range.

Warm the bike completely, and shut it off.

As already stated, start with the pilot circuit. Turn the airscrew all the way in, then turn it out 1.5 turns to start. Start the engine, and turn the idle

screw in until you get a slightly fast idle, or hold the throttle just barely cracked, to keep the engine idleing. Turn the airscrew slowly in, and then

out, until you find the point where the idle is fastest. Stop there. Do not open the screw any farther, or your throttle response will be flat and

mushy, and the bike may even bog. This is only the starting point, we will still have to tune the airscrew for the best response.

Now is the time to determine if you have the correct pilot installed in your carb. The airscrew position determines this for you, making it very

simple. If your airscrew is less than 1 turn from closed, you need a larger pilot jet. If it is more than 2.5 turns from closed, you need a smaller pilot jet.

Once you have determined (and installed it if it's necessary to change it) the correct pilot jet size, and tuned the airscrew for the fastest idle, it's

time to tune the airscrew for the best throttle response. Again, make sure the bike is at full operating temperature. Set the idle back down (the bike

should still idle, despite what you read in the Moto Tabloids), and ride the bike, using closed-to-1/4 throttle transitions. Turn the airscrew slightly in

either direction until you find the point that gives you the best response when cracking the throttle open. Most bikes are sensitive to changes as

small as 1/8 of a turn.

The airscrew is not a set-it-and-leave-it adjustment. You have to

constantly re-adjust the airscrew to compensate for changing outdoor temps and humidity. An airscrew setting that is perfect in the cool

morning air will likely be too rich in the heat of the mid-day.

Now, it's time to work on the needle. Mark the throttle grip at 1/4 and 3/4

openings. Ride the bike between these two marks. If the bike bogs for a second before responding to throttle, lower the clip (raising the needle) a

notch at a time until the engine picks up smoothly. If the bike sputters or sounds rough when giving it throttle, raise the clip (lowering the needle)

until it runs cleanly. There isn't really any way to test the needle other than by feel, but it's usually quite obvious when it's right or wrong.

Last is the main jet. The main jet affects from 1/2 to full throttle. The easiest way to test it is to do a throttle-chop test. With the bike fully

warmed up, find a long straight, and install a fresh plug. Start the engine, and do a full-throttle run down the straight, through all gears. As soon as

the bike tops out, pull the clutch in, and kill the engine, coasting to a stop. Remove the plug, and look deep down inside the threads, at the base of

the insulator. If it is white or gray, the main is too lean. If it is dark brown or black, the main is too rich. The correct color is a medium-dark mocha

brown or tan.

Once you have a little bit of experience with jetting changes, and you

start to learn the difference in feel between "rich" and "lean", you'll begin to learn, just from the sound of the exhaust and the feel of the power, not

only if the bike is running rich or lean, but even which one of the carb circuits is the culprit.

The slide is also a tuning variable for jetting, but slides are very expensive, and few bikes need different slides, so we won't go into that
here.
Thanks Inda :shock:
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Post by Indawoods »

All or none baby! :supz:
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Post by scheckaet »

do a search and you shall find...
http://www.kdxrider.net/forums/viewtopic.php?t=1156
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Post by canuckhybrid125 »

OK I found out from Ron,that about 8 years ago when they first did the carb mod they used the BEL needles.This bike must be one of the first hybrids made lol.
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Post by bulabula09 »

Inda..i just read the book you just wrote..it really helped me out!...iv been having the same problems with my bike..fouling plugs and running really rich... so thanks for the instructions!!
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