Jetting 101.

83679 Views 158 Replies 113 Participants Last post by qes, 17 d ago

Duane

Discussion Starter · Jul 7, 2006

How to jet the carb on the YFZ.

Step 1: Drain the carb of gas.

Step 2: Unplug the TPS and carb switches to spin the carb. Unplugging is optional. You may have enough room to rotate carb without removing the plugs.

Step 3: Loosen clamps that hold the carb. One on the intake side (not shown) and one on the leaving side of the carb.

Step 4: Spin carb to access the jets by removing the 17mm nut at the bottom of the carb bowl.

Step 5: Replace jets as required. In these pics I removed the bottom of the carb to get better pics. YOU DON'T NEED TO DO THIS!

Step 6: Getting to the needle and clip. Remove the plate on top of the carb.

Under the plate you'll find an allen head screw that needs to be removed to get to the needle and clip.

Remove allen head bolt to remove the needle and clip.

Reach inside the back of the carb to "lift" the needle out.

Needle and clip.

WARNING: DO NOT MOVE THE TPS SWITCH WHILE DOING THIS!

That's my basic "jetting for dummies" tutorial. Make sure everything is clean before doing any of this because dirt is your worst enemy. After you're done make sure everything is put back in place and all switches are plugged in.

EDIT: This is what you'll see on the 06-07 YFZ's when it comes to the fuel screw access. Thanks to Fever2ride for providing the pics.

Yamaha blocked off the access with a plug and you can either pop the plug out by screwing in a sheetmetal screw or take the bowl off and punch it out from the inside.

[attachment=4730:effects3.gif]

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101 - 120 of 159 Posts

popeto93

· #101 · Oct 30, 2009

YFZrider69 and sidewinder thanks for the help boys, i did wat u said and it runs so much smoother and no backfire,

yama450yfz

· #102 · Jan 12, 2010

Ok so I have an 06' YFZ450 with a DASA Classic and a velocity intake with K&N this intake eliminates the airbox with a metal tube. The jets I have in there now are The Dynojet DJ146 main and the DPJM048 pilot with the needle on the second clip does this set up sound ok I am at about 800ft above sea level. I was told I would need a 170 main and a 48 pilot for my set up I know the Dynojet kit is measured by diameter but what does it equate too in cc

JIMMYMAC

· #103 · Jan 25, 2010

Hi, I know this is an old thread,but any chance anyone would still have the photos for the jet change procedure?
Thanks,Jimmy

SlinG

· #104 · Jan 25, 2010

Yama pm me with your email and ill send you a document that will help you out.

MattCanada

· #105 · Jan 28, 2010

I could use the pictures from this tutorial aswell lol

SlinG

· #106 · Jan 28, 2010

matt pm me your email

gamble

· #107 · Jan 28, 2010

Me also please.

[email protected]

Thanks.

jswr81

· #108 · Feb 21, 2010

could some one email me the pics too. [email protected]

JIMMYMAC

· #109 · Feb 26, 2010

Hi, Could someone please email me those pics as well? [email protected]

r6realtor

· #110 · Apr 15, 2010

I could DEFINITELY use the pics as well if possible?? thank you!!!!
[email protected]

yfz12led

· #111 · May 6, 2010

If you spin the carb how do u replace the needle I can't seem to get a tool in there to get the top of the carburetor off. Thanks
Pics too please!

[email protected]

Thanks

gomer450

· #112 · May 7, 2010

please help i em goin crazy tryin to figure this out
i have hmf slip on hot caMS stage 1 k&n air filter with no lid stock box
i em at sea level
some people say i need 180 m but only got a 178 and take few days to order a 180 in but most people saY it would be way way to rich
i tried 42, 48pilot & 4th notch ncvq needle 2 to 3 turns air fuel 168.170.172.175.178 i find aounrd the 168 to 172 the bike works better but stumbles up top like 5th gear wide open and its nto the rev limiter i can power threw it and hit the limiter just like a miss like runnin out of gas for split second like a sputter
what do i do or go with
also my plug is a creamy paigy colour on the steel peice but the porcalin part is white

bjbkc

· #113 · May 10, 2010

can someone put the pics back up they dont seem to be workin anymore

TylerZ06

· #114 · May 26, 2010

Well I really did something wrong last night... I have been messing with the jet settings for the past 2 nights. We are getting ready to go to lil sahara this weekend and I wanted to fine tune the jetting to make it run better and get rid of the top end bog I was having. Well I keep trying different jets ands went last night to yamaha to get an NCVQ needle (mine is 06 non adjustable) and a few more jets.. well they didnt have any jets I needed and didnt have the needle either.. So I took my needle out to see if it was ever changed by the previouis owner and it was not.. I though to my self why dont I notch my own..I did with a dremel and clip went on!! back to gether and it would not idle.. Adjusted and adjusted jets..got so bad I put the clip back on the stock part of the needle and still will not idle.. ANY IDEAS on what I did or what could be wrong??? Is the carb slide supposed to close all the way when the throttle is not pressed? mine dosent.. I just dont know what I screwed up.. I leave in 2 days and dont know what to do.. I wish I would have left it alone LOL..

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leo.vasquez

· #115 · May 26, 2010

QUOTE (TylerZ06 @ May 26 2010, 09:33 AM) index.php?act=findpost&pid=857407

Well I really did something wrong last night... I have been messing with the jet settings for the past 2 nights. We are getting ready to go to lil sahara this weekend and I wanted to fine tune the jetting to make it run better and get rid of the top end bog I was having. Well I keep trying different jets ands went last night to yamaha to get an NCVQ needle (mine is 06 non adjustable) and a few more jets.. well they didnt have any jets I needed and didnt have the needle either.. So I took my needle out to see if it was ever changed by the previouis owner and it was not.. I though to my self why dont I notch my own..I did with a dremel and clip went on!! back to gether and it would not idle.. Adjusted and adjusted jets..got so bad I put the clip back on the stock part of the needle and still will not idle.. ANY IDEAS on what I did or what could be wrong??? Is the carb slide supposed to close all the way when the throttle is not pressed? mine dosent.. I just dont know what I screwed up.. I leave in 2 days and dont know what to do.. I wish I would have left it alone LOL..[/b]

Have you removed your carb or just turned ? Maybe you have misplaced the TPS Switch. I am not sure but I have seen some where here that you can bypass it or just disconnect. Try to search in the web or in the forum for keywords such as "not idle" "tps switch" "bypass". Or you wait for some more solution from other members.

TylerZ06

· #116 · May 27, 2010

QUOTE (Leo Harmen @ May 26 2010, 07:45 AM) index.php?act=findpost&pid=857408

Have you removed your carb or just turned ? Maybe you have misplaced the TPS Switch. I am not sure but I have seen some where here that you can bypass it or just disconnect. Try to search in the web or in the forum for keywords such as "not idle" "tps switch" "bypass". Or you wait for some more solution from other members.[/b]

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well i am still stuck..i did not remove the carb just turned it to install the new needle and jets.. it is a jd jet kit and i am using the blue needle and pretty much have tried every combo and adjustment possible... it will not idle.. i can get it to where i just barely hold the throttle just a tad and it is where it needs to be but i can not seem to get it to that point. I tried up and down on jets, needles, fuel screw and the idle up adjustment and still no dice.... my fingers hurt and tired and dont know what else to do.. gonna try moving the needle a little further but then i need some sleep.. sucks i was supposed to leave friday for lil sahara and now I may not... if I could just get it back to where it was i would b happy..

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leo.vasquez

· #117 · May 27, 2010

QUOTE (TylerZ06 @ May 27 2010, 10:34 AM) index.php?act=findpost&pid=857533

--------------------------------------------------------------------------------
well i am still stuck..i did not remove the carb just turned it to install the new needle and jets.. it is a jd jet kit and i am using the blue needle and pretty much have tried every combo and adjustment possible... it will not idle.. i can get it to where i just barely hold the throttle just a tad and it is where it needs to be but i can not seem to get it to that point. I tried up and down on jets, needles, fuel screw and the idle up adjustment and still no dice.... my fingers hurt and tired and dont know what else to do.. gonna try moving the needle a little further but then i need some sleep.. sucks i was supposed to leave friday for lil sahara and now I may not... if I could just get it back to where it was i would b happy..[/b]

What needle is there now and what pilot and main jets (Brand and size) ?

TylerZ06

· #118 · May 27, 2010

QUOTE (Leo Harmen @ May 27 2010, 09:50 AM) index.php?act=findpost&pid=857536

What needle is there now and what pilot and main jets (Brand and size) ?[/b]

Leo right now it has the stock needle and stock jets. I bought a JD jet kit and I tried the red and blue needle and 48 pilot and up a few sizes and down to a 45 and 168 to a 175 main.. had the needle on 2 thru 6 clips on both needles.. fuel air screw 1 all the way to 4 turns out.. It fires up on any of the settings but it will not idle.. if I hold the throttle cracked open just a lil bit it is where it needs to be but when i let it go that lil bit it dies. I took the bowl off and checked the float, the lil pin holding it in came out and I put it back in. Checked vacumm leaks.. still dont know what else to look at. I have take this thing apart over 20 times trying different things but cant even get it back to where i was before this all started. Did I miss something? when I turned the carb on its side did something get blocked? should I remove something to see? just need some help and very frustrated.

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jchase2004

· #119 · Jul 21, 2010

HI CAn someone please email me those pics, Im a visual learner!! [email protected] thanks

xjmacx

· #120 · Aug 2, 2010

Can someone email me the pics too please? [email protected]
Thanks!!!

101 - 120 of 159 Posts