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Can I ask a Jetting Question?

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I saw there was a jetting database thread, where people listed their specs on what was working for them.

 

So I started with an '07450X that was 100% stock and running basically fine before I tore into it (not the motor) to do major mods including opening the TOP of the airbox etc., and now it falls flat when I crack it fast, but runs fine otherwise. Where should I be looking? Here's what I recall, but sorry I don't have all the facts offhand. I was just hoping to get some pointers on where I might want to investigate further to get rid of this flatspot? It sounds indicative of too much air too quickly, but I'm in an area I know not much about.

 

Year: ...'07
Elevation: ...150' - '1,500
Temperature Range (°F): ...70 F
Smog (AIS): ...No
Airbox Modified Top: ...Yes
Airbox Modified Sides: ...NO
Backfire Screen: ...Yes
Air Filter: ...Uni
Pilot Jet: ...JD recommended in Kit
Main Jet: ...JD recommended in Kit
Needle: ...JD recommended in Kit
Needle Clip Position from top: ...JD recommended in Kit
Fuel Screw Type: ...long aftermarket
Fuel Screw Setting: ...Don't Recall
AP Modified: ...No
Leak Jet: ...?
AP Cover: ...boyesen quickshot set at 1mm
Exhaust Type: ...Megabomb with Q4
Exhaust Modified: ...?
Pink Wire Modified: ...?

 

RZ Rob

 

 

 

 

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Remove boyesen quick shot and throw it away....far away

 

Make sure you are running a 45 pilot (stock head/ 48 modified)

 

Change to the JD Red needle 4tjh clip, or better yet (richer) the Keihin NCVS needle 4th clip

 

Upgrade your apump system to 2008 specs

Put in a 50 leak jet

 

Upgrade you apump linkage with the Tokyo mods or Merge or R&D spring

 

Clean the apump nozzle with really fine piano/gutair string wire

 

Lift up the subframe after installing everything to verify squirt aim, distance, and duration, and that it never hits the slide (just barely)

 

Details:

 

http://www.thumpertalk.com/topic/1093495-fuel-screw-and-jetting/

Edited by Kah Ran Nee
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That's a lot to go through, but I don't mind doing it. I was hoping for specific direction on what was causing the situation I was describing. Sounds like you're saying it's a whole bunch of stuff. I'm thinking fuel isn't getting there fast enough when I crank the throttle WOT quickly. In agreement with some of your points that the Accelerator Pump area deserves a closer inspection.

 

RZ Rob

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Hello RZRob.  I know that sounds like a bunch of stuff, but when its with the carb its really all tied into each other.  The Accelorator Pump (AP)needs to be modified to squirt harder and faster so that when you blip the throttle you are getting the fuel you need at that instant.  The list that Kraine adviesed you to do is right on for you issue.  Its very important to make sure that you have the "squirt" timed just right.  It needs to squirt to the right side of the intake when you are looking into the back of the open carb.  It also needs to every so barely miss hitting the slide when you blip the throttle.  The squirt should be strong looking and last about a second.  In order to get the AP set up correclty you will need to do the list of things that Kranie spelled out. Good luck and let us know how it goes.

Edited by WarHammer0106

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That's a lot to go through, but I don't mind doing it. I was hoping for specific direction on what was causing the situation I was describing. Sounds like you're saying it's a whole bunch of stuff. I'm thinking fuel isn't getting there fast enough when I crank the throttle WOT quickly. In agreement with some of your points that the Accelerator Pump area deserves a closer inspection.

 

RZ Rob

 

It's only two things: jetting, and the apump proper tuning

 

...or you could just give up.

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Rob these guys above me are spot on. Follow the advice above and you will be happy. My friends 07 I did exactly as described above and it runs great no bog. Now remember you can always bog it while it's on a stand and cracking the throttle.

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Rob these guys are right however you can cheat a bit. If you mod the accel pump rivet by shortening it and stretching the spring (do a search) until it stays in contact with the arm even at wot. Oring mod, spring is better though I used R&D, you must fit the #50 leak jet. I used a NCVS as mentioned. Then check the spray for duration and that under NO circumstances does it hit the slide at all not even a whisker, check this with both fast and slow opening of the throttle. 

 

 

Marty 

Edited by MartyMOOSE

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Remove boyesen quick shot and throw it away....far away

 

Make sure you are running a 45 pilot (stock head/ 48 modified)

 

Change to the JD Red needle 4tjh clip, or better yet (richer) the Keihin NCVS needle 4th clip

 

Upgrade your apump system to 2008 specs

Put in a 50 leak jet

 

Upgrade you apump linkage with the Tokyo mods or Merge or R&D spring

 

Clean the apump nozzle with really fine piano/gutair string wire

 

Lift up the subframe after installing everything to verify squirt aim, distance, and duration, and that it never hits the slide (just barely)

 

Details:

 

http://www.thumpertalk.com/topic/1093495-fuel-screw-and-jetting/

Did all this. It seemed to wake the bike up nicely, thanks.

 

RZ Rob

IMG_0416_zpsd7b743b9.jpg

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