Mattchev Posted January 21, 2016 Report Share Posted January 21, 2016 (edited) 87 banshee fmf fattys and power core II silencers, pro flow air filter (just cleaned), boyesen reeds. Stock carbs freshly rebuilt, jets all cleaned out. spotless. I CANNOT figure this thing out. 27.5 pilot, 290 main. compression test good and no leaks. Im also not the most experienced with jetting. I have another banshee with pretty much the same setup and runs absolutely perfect with 27.5 and 300. the 87 is not even close to running good. Starts first kick and idles all day, very slight bog off the start and will not get on power band. Just doing some experimenting with the needle clip, the bike runs the best with the clip all the way at the bottom. Any suggestions? do I need to go up more on main jet? I thought reeds were the issue at first.. so i pulled them out and what do ya know.. there was a crack in one of them. So went and got boyesens and put them in, and fixed problem slightly but still not all the way. Edited January 21, 2016 by Mattchev 1 Quote Link to comment Share on other sites More sharing options...
Mattchev Posted January 21, 2016 Author Report Share Posted January 21, 2016 87 banshee fmf fattys and power core II silencers, pro flow air filter (just cleaned), boyesen reeds. Stock carbs freshly rebuilt, jets all cleaned out. spotless. I CANNOT figure this thing out. 27.5 pilot, 290 main. compression test good and no leaks. Im also not the most experienced with jetting. I have another banshee with pretty much the same setup and runs absolutely perfect with 27.5 and 300. the 87 is not even close to running good. Starts first kick and idles all day, very slight bog off the start and will not get on power band. Just doing some experimenting with the needle clip, the bike runs the best with the clip all the way at the bottom. (**Gets worse the higher the clip goes on needle**) Any suggestions? do I need to go up more on main jet? Screws are about .5 turns out. Bike wants to die the further out i turn them. I thought reeds were the issue at first.. so i pulled them out and what do ya know.. there was a crack in one of them. So went and got boyesens and put them in, and fixed problem slightly but still not all the way. Quote Link to comment Share on other sites More sharing options...
Phelps Posted January 21, 2016 Report Share Posted January 21, 2016 if it runs better with the needle all the way down it needs a smaller main jet. maybe a little more detail. rough bog with no top is typically rich. crisp bottom with a smooth bog on top as it starts to pull is lean. im use to seeing 320 on main with similar setup, but ive always ran a k&n which requires a bit more main. i would drop 2 sizes on the main and if it's night and day you're going in the right direction. if no improvement or worse go the other way. Quote Link to comment Share on other sites More sharing options...
Mattchev Posted January 21, 2016 Author Report Share Posted January 21, 2016 if it runs better with the needle all the way down it needs a smaller main jet. maybe a little more detail. rough bog with no top is typically rich. crisp bottom with a smooth bog on top as it starts to pull is lean. im use to seeing 320 on main with similar setup, but ive always ran a k&n which requires a bit more main. i would drop 2 sizes on the main and if it's night and day you're going in the right direction. if no improvement or worse go the other way. i appreciate the input. should i put the needle back in the middle and then drop down on the main? of keep it at the bottom and drop it down and see what happens? Quote Link to comment Share on other sites More sharing options...
Phelps Posted January 21, 2016 Report Share Posted January 21, 2016 I would put the needle back in the middle for now Quote Link to comment Share on other sites More sharing options...
Mattchev Posted January 21, 2016 Author Report Share Posted January 21, 2016 I would put the needle back in the middle for now went down to 270 and wasnt much better. tried 300 and seems like it was a little more clear but at 1/2-full throttle theres just no power. ill go up a few more steps on main just to see how it reacts Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted January 21, 2016 Report Share Posted January 21, 2016 Are they genuine Mikuni jets? Have you done a plug chop/read? What temps/elevation? If a person has lack of experience in jetting it's safer to go richer first. Quote Link to comment Share on other sites More sharing options...
Mattchev Posted January 21, 2016 Author Report Share Posted January 21, 2016 Are they genuine Mikuni jets? Have you done a plug chop/read? What temps/elevation? If a person has lack of experience in jetting it's safer to go richer first. yes genuine mikuni jets. its about 35 degrees here at sea level. Plug chop shows very light brown. I'll try to post pic Quote Link to comment Share on other sites More sharing options...
Shee_fast Posted January 21, 2016 Report Share Posted January 21, 2016 Light brown is lean and dark is rich... You want a good chocolate color Sent from my VS810PP using Tapatalk Quote Link to comment Share on other sites More sharing options...
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