Screaming Meemie Posted August 24, 2012 Report Share Posted August 24, 2012 So i brought my 'Shee from MN (elev. 900ft) to MT (elev. 4900ft) and switched the carb settings to 300 mains, needle on clip #4 and air screw 3 turns out. I tried the jetting calculator on here and used 330 mains & it was rich & real shitty on the mid/top end, the 300's seemed to have fixed that & the bottom is pretty crisp too. It runs well, sounds good, and isnt fouling plugs, but the power i had in MN isnt quite all there. I ran 230 mains, stock pilots (25), stock needle and 2 turns out on the screws in MN & it ran just perfect.. tons of power & just peachy. Does the 4000ft increase make that much of a difference in power or should i re-tune? Quote Link to comment Share on other sites More sharing options...
2004LEBanshee Posted August 24, 2012 Report Share Posted August 24, 2012 Less Oxygen per volume the higher you go up. 4000 ft is a lot and will make less power. Need to drop the jetting as you go up. you have a lot less compression now and you probably suffer on the low end. Quote Link to comment Share on other sites More sharing options...
BUILDER Posted August 24, 2012 Report Share Posted August 24, 2012 So you went up in elevation and also went up in jetting is that really what you are saying? If that is really what you did then you went backwards you need to drop your jetting when you go up in evelvation. Quote Link to comment Share on other sites More sharing options...
Screaming Meemie Posted August 24, 2012 Author Report Share Posted August 24, 2012 So you went up in elevation and also went up in jetting is that really what you are saying? If that is really what you did then you went backwards you need to drop your jetting when you go up in evelvation. I was going off of what the calculator told me, as a start point.. it said 330 which was way rich so i went down to the 300's which is what i originally put in after i added the pipes & other mods. Then i took it to the dealer this past april cuz i couldnt get it to idle (bent needles) and they put in 240's cuz it was rich with the 300's evidently. Thats what i was running in MN & it ran perfectly all summer. Quote Link to comment Share on other sites More sharing options...
Screaming Meemie Posted August 27, 2012 Author Report Share Posted August 27, 2012 anybody running at similar elevation & conditions as Bozeman, MT? just looking for suggestions on how to find my missing power gonna try 280 mains, 27.5 pilots & stock needle & screw settings & go from there. any help from you gods of the twin cylinder would be choice. Quote Link to comment Share on other sites More sharing options...
Nightmare Posted August 27, 2012 Report Share Posted August 27, 2012 Is it ported? Im riding at 5000ft and im running 290 mains, stock needles in the middle clip, 25 pilots and 1.5 turns out on a non ported motor. Hope this helps. Quote Link to comment Share on other sites More sharing options...
Screaming Meemie Posted August 28, 2012 Author Report Share Posted August 28, 2012 Is it ported? Im riding at 5000ft and im running 290 mains, stock needles in the middle clip, 25 pilots and 1.5 turns out on a non ported motor. Hope this helps. nope, not ported. thanks for the help, im gonna try the stock pilots with the 280 mains in the morning to see if i'll need the 27.5's at all. probably just put the needles & screws back to stock for starters. Quote Link to comment Share on other sites More sharing options...
Nightmare Posted August 28, 2012 Report Share Posted August 28, 2012 Quote Link to comment Share on other sites More sharing options...
dave5.0 Posted August 28, 2012 Report Share Posted August 28, 2012 You aren't gonna have the power u had. Unless you add something to make more power. Just the way it works with elevation. If you wanna be safe on your jetting though keep going up jet sizes till it starts to sputter, then back it down till it clears out. You can do that with your mains and the needle. Your pilots you should end up somewhere around 1 1/2-21/2 turns out on your airscrews. If its less your jets are too big. If you go out further your jets are too small. The way I always set the airscrews is get the motor warm and idling decent speed. Then start with both screws in the same position. Turn both screws equal amounts in or out till u get the highest idle. If you end up where I told ya in turns you're good to go. Then after that set your idle speed where u want it. Quote Link to comment Share on other sites More sharing options...
jbooker82 Posted August 28, 2012 Report Share Posted August 28, 2012 Higher Evevation = Less Oxygen = Less fuel. You dont go up in elevation and increase the main jet size. I would start out with how you had it jetted at 900 ft and work down from there. Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted August 29, 2012 Report Share Posted August 29, 2012 ...wait, so when did 4900ft become elevation? LOL! Quote Link to comment Share on other sites More sharing options...
Screaming Meemie Posted August 29, 2012 Author Report Share Posted August 29, 2012 Higher Evevation = Less Oxygen = Less fuel. You dont go up in elevation and increase the main jet size. I would start out with how you had it jetted at 900 ft and work down from there. Yeah duh right? haha. trying that tomorrow.. the 300s didnt really make sense to me but i decided to try the calculator thing. im a pro at carb tear downs now at least Quote Link to comment Share on other sites More sharing options...
jbooker82 Posted August 31, 2012 Report Share Posted August 31, 2012 (edited) Yeah duh right? haha. trying that tomorrow.. the 300s didnt really make sense to me but i decided to try the calculator thing. im a pro at carb tear downs now at least Well let us know how it goes. You will still see a little loss due to the lower compression but that can be fixed using a cool head with smaller domes. It will bring the compression back up if you plan on running at that elevation for a while. Edited August 31, 2012 by jbooker82 Quote Link to comment Share on other sites More sharing options...
Screaming Meemie Posted September 7, 2012 Author Report Share Posted September 7, 2012 Welp, i think i got 'er as good as she's gonna get! Did a plug chop with 200 mains & it was too lean so i went with 220's. I havent done a chop with em, but the engine feels good. I kept the stock pilots and moved the clip one position leaner on the needles (2nd from top now) and im at 3.25 turns out on the screws. She's a tad rich at real low rpms (maybe i 'll go 3.75 turns out) but other than that its great. With the +2 teeth (16) front sprocket i can still get 3rd gear wheelies with a little body english... the torque has basically moved down a gear. No more wheelies in 4th like at 900ft, but considering im using my 'Shee as a commuter and a weekend ripper, im pretty ok with it. I was actually thinking about a cool head... if i got different sized domes for different elevations would that help without creating a jetting nightmare? Quote Link to comment Share on other sites More sharing options...
dave5.0 Posted September 7, 2012 Report Share Posted September 7, 2012 (edited) Welp, i think i got 'er as good as she's gonna get! Did a plug chop with 200 mains & it was too lean so i went with 220's. I havent done a chop with em, but the engine feels good. I kept the stock pilots and moved the clip one position leaner on the needles (2nd from top now) and im at 3.25 turns out on the screws. She's a tad rich at real low rpms (maybe i 'll go 3.75 turns out) but other than that its great. With the +2 teeth (16) front sprocket i can still get 3rd gear wheelies with a little body english... the torque has basically moved down a gear. No more wheelies in 4th like at 900ft, but considering im using my 'Shee as a commuter and a weekend ripper, im pretty ok with it. I was actually thinking about a cool head... if i got different sized domes for different elevations would that help without creating a jetting nightmare? 3.25 turns on the air screw is past the point of doing anything. Sounds like your pilots are too big. How are you tuning the air screw? Did you ever tell is what parts are in this thing? Edited September 7, 2012 by dave5.0 Quote Link to comment Share on other sites More sharing options...
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