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jetting at 3,000 feet..


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Hey guys nice site I have a question for one of my banshe e's today... it's a 2000 with fmf sst v force 2 reeds boost bottle stock air box but completely cut off with the 1 big k&n air filter at 3,000 feet.. it's my girls bike and I'm trying to dial it jn.. I know the main jet is a 320 and all others are stock.. what is the proper jetting for this stock bike??? thanx looking forward to the responds

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Personally I'd go 30 on pilot 25 is stock and stay at 320 due to your elevation And having no air box and thats at 70deg maybe more on main depending on how cold it is

 

Sent from my Galaxy Nexus

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pilot will be set by how far you have to have your airscrew set at, if the sweet spot on air/fuel screw is 1/2 turn or less then you need a larger pilot*, if its more then 2.5 then you need a smaller pilot. Ive found that aftermarket reeds usually need a fatter pilot to start out with or you end up with an off idle dead spot. i have pretty much the same set up as you described fmf pipes and my airbox lid is removed with a k&n filter but im at 800ft asl and i found that 30/300 was perfect for me and with every 1500ft-2000ft of elevation you need one size SUBTRACTED to main with the same base temperature.

 

 

EDIT: mixied up effects on elevation change. edited should be accurate now. also meant pilot not airscrew

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pilot will be set by how far you have to have your airscrew set at, if the sweet spot on air/fuel screw is 1/2 turn or less then you need a larger air screw, if its more then 2.5 then you need a smaller pilot. Ive found that aftermarket reeds usually need a fatter pilot to start out with or you end up with an off idle dead spot. i have pretty much the same set up as you described fmf pipes and my airbox lid is removed with a k&n filter but im at 800ft asl and i found that 30/300 was perfect for me and with every 1000 ft of elevation you need one size added to main with the same base temperature. thats why i suggested that 320 was probably really close already. pilot is definately too small tho.

 

I agree with everything you said except ^^^.

With every 2000ft asl you need to go down 1 main jet size due to thinner air so you need to lean out the main jet not richen it, so probably a 280 main jet would be where he needs to be, not 320.

 

Try a 30 pilot jet, but if you find yourself unscrewing the airscrew more than 2.5 turns out to get a crisp throttle snap go down to a 27.5 and start off 1.5 turns out and see how that feels.

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And if you really want to tune the carbs, get a Carb Sync Tool from FAST.  http://www.farmandsandtoys.com/partdetail.asp?partid=59

And also a cheap tachometer for setting idle.  http://www.ebay.com/sch/i.html?_trksid=p2050601.m570.l1311.R1.TR4.TRC2.A0.X2+stroke+tach&_nkw=2+stroke+tachometer&_sacat=0&_from=R40

I have 1 just like the 1st one.

Helps with setting idle and carb syncing at 5500rpm.

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I agree with everything you said except ^^^.

With every 2000ft asl you need to go down 1 main jet size due to thinner air so you need to lean out the main jet not richen it, so probably a 280 main jet would be where he needs to be, not 320.

 

Try a 30 pilot jet, but if you find yourself unscrewing the airscrew more than 2.5 turns out to get a crisp throttle snap go down to a 27.5 and start off 1.5 turns out and see how that feels.

you are correct sir, what was i thinking yes it should be less jetting for more elevation due to thinner air. good catch

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