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Quick jetting advice

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Hello buddies

 

I just put a quiet insert in my SM. It makes it quieter, but also obviously less air is coming through. It is now running much too rich, I can even smell the gas. It barely wants to start, whereas before it would start after first or second turn. 

 

Right now (before any changes) I have:

 

Jetting (from JD jet kit, remaining pieces available):

Stock mikuni carb

160 MJ

25 PJ

Blue needle 3rd clip?

Extended fuel screw (uknown turns out, i just futz with it until it feels ok)

 

Fuel system:

FMF Powercore 4 muffer (V1 Universal)

FMF Powerbomb header

K&N high air flow filter

 

Conditions:

Wisconsin

~700 ft elevation

Summer temps ~70-80

 

I am imagining I will just go down to a 155 MJ and 22.5 PJ. So I need advice on if those jets sound good, as well as what needle and clip position to use. I am not really sure about how the needle effects performance.

 

Let me know what you think!

 

Thanks

Edited by Zeeno

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Yup its definitely blue needle third clip. Is it the farther you make the clip from the tip of the needle, the leaner it becomes because it blocks more of the main jet?

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Well I reinstalled it. I looked at the JD jet kit advice and kept the 25 pilot jet.

 

Now it will run but starting is difficult. It will die unless I have the throttle on. Is this something I can fix with the fuel screw and idle speed or do I need to change jetting again?

 

Now it has

155 MJ

25 PJ

blue needle 3rd clip

 

I also realized I had the spacers on the needle flipped around so the thick washer was on the wrong side of the clip so I fixed that.

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Try installing the 4th clip position if it still feels weird. 22.5 pj with ex fuel screw the sweet spot for me is around 2.5-2.75 turns out

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Try installing the 4th clip position if it still feels weird. 22.5 pj with ex fuel screw the sweet spot for me is around 2.5-2.75 turns out

+1 I run 155 MJ / 22.5 PJ + ext fuel screw / 4th clip / with quiet core.

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Anyone else have input before I take the bike apart and back together again?

 

Main jet: 155

Needle: Blue on clip 3 (move to clip 4 if you encounter surging while cruising)

Pilot jet: 22.5 

Fuel screw: 2.75 turns out then fine tune using this http://www.thumpertalk.com/topic/271735-how-to-confirm-your-pilot-circuit-setting/

 

 

ScreenShot2014-04-21at121205PM.png

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Main jet: 155

Needle: Blue on clip 3 (move to clip 4 if you encounter surging while cruising)

Pilot jet: 22.5 

Fuel screw: 2.75 turns out then fine tune using this http://www.thumpertalk.com/topic/271735-how-to-confirm-your-pilot-circuit-setting/

 

 

ScreenShot2014-04-21at121205PM.png

What does surging feel/sound like? I hear about it a lot but don't know if i've ever experienced it or not.

Edited by Zeeno

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What does surging feel/sound like? I hear about it a lot but don't know if i've ever experienced it or not.

 

Trust me, when it happens you will know. It kind of feels like somebody has a rope tied to the back of the bike and they keep tugging on it.

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