Jetting

[Drzclaud]

06 400s, I'm running a stock main jet, JD kit, 3x3, Yosh exhaust, will this work at 4000 ft?

Thanks

C

[30x26]

stock main jet is too small for you.

try blue needle at 3rd clip and 155 main

[isu22andy]

stock main jet is too small for you.

try blue needle at 3rd clip and 155 main

Thats what Im running on my stock exhaust .  I think JD says to go to 160 main and 25 pilot for aftermarket exhaust

[OverSquareEng]

Thats what Im running on my stock exhaust .  I think JD says to go to 160 main and 25 pilot for aftermarket exhaust

 

OP is at 4,000 ft, the smaller main jet is to compensate for the elevation.

[Drzclaud]

Thanks for the reply!.....don't know if it makes a difference but I have the DynoJet kit, not the JD. Stock main jet, 3x3 and Yosh exhaust, still apply.

 

Thanks

C

[30x26]

with dynojet needle at your elevation you could try 152.5 or 150 

 

 

<sub>2. Install the Dynojet needle on groove #2 from the top. Use all stock
spacers (Fig. A). The small Dynojet washer is for half step increments and
does not have to be installed at this time. Install the Dynojet slide spring
(DSP026) in place of the stock slide spring. NOTE: The DSP77 spring
does not have to be used, it is supplied in case the stock spring is
misplaced. After installing the slide in the carb be sure to check slide
movement manually before airbox installation.
3. Remove the stock a main jet and replace with the Dynojet main jet
provided. If you are running the stock exhaust install, the DJ150 main jet.
If you are running an aftermarket exhaust or slip-on with a high flowing
baffle, use the DJ155 main jet. Be sure that the jet you are changing is the
main jet.
4. Locate the fuel mixture plug (Fig. . If you see a screw head at Fig. B
proceed to adjusting procedure. With the 5/32 drill bit provided carefully
drill through the plugs. NOTE: The mixture screw is directly underneath
this plug, be ready to pull back on the drill the instant you break through.
Use screw provided to secure and remove this plug. Carefully turn
mixture screws clockwise until lightly seated, then back out 3.5 turns.</sub>

Edited November 18, 2015 by 30x26

[Drzclaud]

Thanks, my kit came with only a 128, 130, 132, 134 and 138. How bad will it run with my stock jetting? Do you think I can get by with just moving the needle ?

Thanks

C

[30x26]

leave the needle at second clip and buy a 152.5 main,

moving the clip it's not the same thing, it does not affect full throttle. 10 points less than recommended is too lean

Edited November 19, 2015 by 30x26

[Drzclaud]

I'll do that.....thanks for your help 30x26 I appreciated.

 

C

[Drzclaud]

30x26....BTW, I've put about 20k miles on it with the current setup ( stock main jet, stock pilot, JD kit, 3x3 and Yosh exhaust,) and it runs very well, should I use the 152 for this weekends ride at 4000 ft and

install a 155 for lower elevations ?

 

again thanks

C

[30x26]

yes.  those sizes apply to main jets by dynojet and are based on dynojet paper coming with the kit. 

 

someone says that a main jet by dynojet flow differently than same size by keihin, someone says there is no real difference.

i'm not 100% sure that a 152.5 keihin will give the best result, if possible buy a main jet manufactured by DJ

[Drzclaud]

Ok, thanks for your help.

C