jetting Q

[Bansheerook]

i got my fatties delivered today. Tomorrow I'm going to install them with turbine cores. I have a k&n and I'm going to rmove my snorkel. FMF sent 260 mains and told me to get 30 pilots. The 30s sound ok but the 260s sound small. What do you guys think?

[biggun6ss]

Well lets see. We need to know around what elevation you are riding at and do you have any aftermarket reeds, porting. If I were you I would by main jets that range from 260-350. That way if you ever get any more mods you have the jets for it. Best way to check jetting is look at your plug. I spent a lot of time swapping jets, ridding, pulling plugs, and looking for the right color.

 

I don't think you will be needing 30's for the pilot if the pipes and filter are all you have for mods.

[Bansheerook]

ok. im off to buy some extra plugs also then.I'm eager to get my baby fixed today so i can ride her. My elevation is about 500. Its in the sixties right now but when summer comes its damn hot.high 90s-100's. dry heat though. oh yeah, htose are the only mods I have........for right now

[banshee tuner]

I'd say start with a 300 main and the 27.5 pilot and that should get you close enough to dial it in from there.

[Bansheerook]

Well I picked up my mains and pilots. Im going to try what fmf said to do I guess. The biggest main I could get was 280 and I got a 27.5 & 30.0 pilot. Fmf said to use the 260 their pipes came with and to get a 30 for the pilot jet. Everyone is saying to start at a 300 main and work down, and that a 30 pilot is prob. too much. Does installing a 30 pilot make up for installing a small 260 main. Its crazy. Thx for the help.

[Hilarious]

If your K&N filter is clamp on, I'd suggest getting finding some 300's on up to 340's and pull that lid off your air box. It will run a lot better. My fatties hit pretty hard as soon as pulled the lid off. You can try magic racing or dennis kirk on the internet to order yourself some more jets.

Edited March 12, 2006 by Hilarious

[midnite]

If your K&N filter is clamp on, I'd suggest getting finding some 300's on up to 340's and pull that lid off your air box. It will run a lot better. My fatties hit pretty hard as soon as pulled the lid off.  You can try magic racing or dennis kirk on the internet to order yourself some more jets.

485431[/snapback]

Word.

[Bansheerook]

ok. threw my back out this weekend and haven't had enough energy to update. Here goes. Since I could only get 280 mains sat. i went ahead and tried them. I used the stoke mount for my K&N. Just cut the cage off of it. It calmps onto that. I guess thats a clamp on. The pilots they gave me were the wrong ones so I left in the stocks. I removed the snorkel but not the lid. It seemed to idle kind of high. It smoked a lot when it was cold but after the bike warmed up just barely smoked at all. But evenly out of both pipes. It seemed to run decent but havent had a chance to go somewhere and go through all the gears. Put new plugs in and checked them. They were a creamy brown color. Only got 3rd gear pinned. Seemed to hesitate a couple of times. Definately more power. Wheres the idle screw at on an 05? Should I adjust it. Still think I should throw 300 mains in there?

[Wicked98Shee]

if ur runnin the lid and no snorkel 280 should be real close depending on ur altitude. im at 850ft and for 70deg. my 98 has, fatty's, k&n w/ proflow and no lid, vf3's and it jet's out at 280 main,stock pilot,1 turn on air screw.

[Bansheerook]

ok thx, im at about 500 feet. I havn't gootin her in the dirt yet still. I did get her in 5th gear though and a pretty good ways through. My plugs look good. She needs a little more throttle takin off in first but the rest of the gears (only most of the way through 5th)are very responsive. In first it needs a little more gas than before or she'll try to stall out. I've only changed the main jet, should I turn the air screw and do I turn it out or in from the point its at right now. Thx for the help.

[Hilarious]

ok thx, im at about 500 feet. I havn't gootin her in the dirt yet still. I did get her in 5th gear though and a pretty good ways through. My plugs look good. She needs a little more throttle takin off in first but the rest of the gears (only most of the way through 5th)are  very responsive. In first it needs a little more gas than before or she'll  try to stall out. I've only changed the main jet, should I turn the air screw and do I turn it out or in from the point its at right now. Thx for the help.

486924[/snapback]

 

Turn your air screws in to richen your carbs. Whatever adjustment you make to one carb make sure you do to both carbs. Make your adjustments with the bike running and allow about 10 or 15 seconds for the engine to respond to the new settings.I'd say if you get to turning your screws in to half a turn from closed, then you need to get the next size pilots and start the process over.

WHen you turn your air screws in, do not fully tighten them as you will ruin the screws.

Also read this.......JETTING FAQ

Edited March 15, 2006 by Hilarious

[Bansheerook]

Ok, I'll try turning the air screws in tomorrow. I'm not understanding the science though.

If I turn my air screws in I'm getting less air, right? I put a k&n on to get more air. Why am I cutting it off now? If i'm just barely stalling a little bit, and only in first, how far off am I? Why would I go to a bigger jet just from adjusting the air screw?

Thx for everyones help. This site has and is teaching me a lot.

 

PS. wheres the jetting for dummies book when I need it

[Hilarious]

Q#10:I have a bog or hesitation right off idle, OR an erratic idle, OR a very high or low idle...

A#10:Since the problem is between 0 and 1/8 throttle, the pilot/airscrew circuit may be rich or lean, and you may need to also adjust the idle speed screws and check the carb synchronization (see Q#23 & 24).  Start by adjusting the airscrews; on each carb turn them in (clockwise; which is richer) a half turn (180 degrees); adjust both airscrews the same amount.  If you have the motor idling allow about 20 seconds for the motor to react to the new setting.  If the condition gets worse, try going out (counterclockwise; which is leaner) on the airscrews and see if it improves.  If going in on the airscrews helps but the problem persists after you turn the airscrews all the way in, or to within a half turn out from seated (don't torque the airscrews!  the tip is pointed and overtightening them can cause damage!), try the next size larger pilot jet, and start over with the airscrews 1.5 turns out; tune the airscrews from there to get a clean idle and off-idle response.  Conversely, if going out on the airscrews helps but the problem persists after you get to about 3 turns out from seated, try the next size smaller pilot jet and start over with the airscrews 1.5 turns out; tune the airscrews from there to get a clean idle and off-idle response.  Once you acheive a clean idle and crisp off-idle response (no bog or hesitation right off idle), you may need to adjust the idle speed up or down by adjusting the idle screws.  If airscrew adjustment does not have any affect on the bog or hesitation, and you are certain the problem is below about 1/4 throttle, check the carb sync, make sure the pilots aren't clogged (it only takes a speck of dirt to block the tiny passage), and insure that both airscrews are set the same number of turns out from seated.  Be advised that the stock Banshee carbs have a pilot jet that is specific to Banshees; a standard Mikuni pilot jet will not work (see next section for pilot jet details).  To verify your pilot/airscrew circuit jetting, start the motor and let it warm up fully; install fresh spark plugs, start it (without using the choke) and let the motor idle for about 10 minutes; pull the plugs and look at the center electrode and base ring; they should be a light chocolate brown color if you're dialed in.  As a side note, since the pilot jets are flowing fuel throughout the throttle range (they are solely responsible for mixture at idle to about 1/8 throttle but continue to deliver fuel above 1/8 throttle) changes made to the pilot jet size MAY have an affect on the main jet jetting; if you change pilot jet sizes it's a good idea to verify your mains as well, and to a lesser extent the needle clip position.

 

Here. I know its a lot to read, but you didnt seem to have clicked on that link that I provided you.

[Bansheerook]

Hilarious You're the man. I didn't even notice that was a link. I get today(thurs) and friday off from work. I'm off to go figure it out now. Thx for the help.

 

It all makes since now.

[Bansheerook]

Ok. I got it into 6th with new plugs. I turned the air screws a half turn in so now their 1.5 turns out. It doesn't stall out at all in first anymore. I took the plugs off after getting it through all six gears w/WOT( all 6 felt good) and putting to my buddies house about .25 miles away. The plugs seem really dark brown. Really dark. My plug chop sucks ass. There is no silver in it I just didn't have a hacksaw and improvised. I will do the other plug after buying a HS if need be. The color goes all around the plug. Looks rich to me. I have 280 mains, stock 25 pilots and air screws 1.5 turns out. I'm tempted to put the 260 mains and 30 pilots ( like fmf recommended ) in to see what happens. What do you guys think? Thx.