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Discussion Starter #1 (Edited)
I am trying to get the jetting right on my 04 660....I live in OH at 100ft. I have a full Yoshi exhaust, Stage 1 Cam, K&N with Outerwears and No Lid.

I installed Vito's Needles with middle clip setting
#25 Pilots
Fuel Screws 2 1/2 out

From 0 to 1/4 throttle everything sounds good finally but It sputters a little at 1/2 to Full throttle and the power feel like stock at best

Im currently running 150L 155R Makumi mains and Iv'e tried 155-160 160-165 all with the same results...So my question is should I bump up to 165-170 or 170-175?

I was running very lean my pipes are dark blue for the first 6-8 inches with flames shooting out of the exhaust and after talking to Yoshi I added a full turn on my fuel screws and the flames went away and the 0-1/4 throttle cleared right up.

I also noticed when I was running the 160-165 jets that only the left head pipe was turning blue and when dropped to the 155-160 both sides started to turn blue. Thats kind of why I was thinking I need to go back to a larger jet setup...if that helps

Thanks Jason
 

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Master of the Electron
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I would think 165L/170R would be a good place to start for you.

Remember that the fuel screws/pilot jets only control idle to 1/4 throttle, needles 1/4 to 3/4 and mains 3/4 to WOT (with a bit of overlap). So you richened up idle by turning out the fuel screws, but this did little or nothing above 1/4 throttle.
 

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Discussion Starter #3
Thanks... I went 165-170 and it made a huge diff. I still have the fuel screws out 2 1/2 and that seems to be the best response I can get for 1/4 throttle without running to lean on a plug test. However when I just hold it at 1/4 while parked I can hear just a slight stumble can you tell me I that's normal? I've never heard a 660 with a stage 1 cam so im not sure if that's just the nature of it. When I just blip the throttle it sounds very crisp and clean.

Thanks
 

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Discussion Starter #4
I decided to go back to 1 1/2 out on fuel screws it still has just a slight stutter when held at 1/4 throttle while parked but the plug came out cleaner instead of on the black side. I'll try this for awhile and see how it goes n
 

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I am unique
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I decided to go back to 1 1/2 out on fuel screws it still has just a slight stutter when held at 1/4 throttle while parked but the plug came out cleaner instead of on the black side. I'll try this for awhile and see how it goes n
You may need to raise the needle some to get rid of the midrange problem.............
 
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