do i need to re jet?

[sickOne]

im not sure if this is a dumb question or not but here I go..i have a 2005 banshee  that besides some cosmetics upgrades is bone stock im gonna install some bills pipes with pro circuit 304 silencers and gonna remove only the snorkel the filter is an aftermarket factory foam replacement I ride between sea level and 250 above sea level, temps between 70 to 90 degrees..do I need to re jet my carbs for this set up and if I have to where is a good point to start.Im a weekend rider and the quad has plenty of power for the kind of trails we ride I just want to upgrade for a better sound but still keep my quad as reliable as its been so far with the factory settings any info would be appreciated..

[wayne_smith97]

Yes you need to rejet. Start with 260 mains and work your way down. Might need to go up to a 27.5 pilot also

[BUILDER]

Yes you will burn it up if you do not rejet. Like Wayne said a 260 main should be pretty close. They come factory with a 190 main so that gives you an idea of how far off your jetting would be if you just tried to run it stock. 

[swhitey917]

Yes you need to rejet. I would start with a 260-270 and work my way down from that. Might need to bump the pilot up a size also but the main will definitely need to be changed before testing.  

[Larry's Shee]

OP, any time you change the amount of air in or out of engine you have to re jet. Bone stock, remove snorkle, +1 jet size, remove lid, +1more maybe 2. Unexact science as all engines are different as are conditions. Read up on how to do a plug chop or how to "read" plugs.

 

There's a sticky in this section "What jets are you running" , or something like that. Look through it, might find simular set-up. At least you will gain some knowledge about set-ups and jetting.

[uman1030]

http://www.dfn.com/agservices/jetfaq.html scroll about 3/4 down the page and there is this. When using this method i find they usually air on the side of too rich. Its just a baseline and it will probably be slightly leaner mains then this suggests

 

Assuming that your jetting is dialed in perfectly, add the following for each mod:

Air filter
Remove snorkel:1-2 sizes larger on the mains, adjust airscrews
Remove airbox lid:1-2 sizes larger on the mains, adjust airscrews
Add foam air filter:0-2 sizes larger on the mains, adjust airscrews
Add K&N air filter:4-6 sizes larger on the mains, adjust airscrews, add one size on pilots if necessary
Add 2 into 1 Foam air filter OR dual carb-mounted foam filters (removing entire airbox, NOT in addition to removing snorkel and airbox lid above):2-4 sizes larger on mains, adjust airscrews, add one size on pilots if necessary
Add Dual K&N carb-mounted air filters (no airbox, NOT in addition to removing snorkel and airbox lid above):4-7 sizes larger on the mains, adjust airscrews, add one size on pilots if necessary
Add Outerwear:no change
Add TORS elimination kit:no change

Pipes
Add Pipes & silencers (all except 2 into 1 pipes):8 sizes larger on the mains, 2 sizes larger on the pilots, adjust airscrews
Note:Some pipes, like CPI and other “drag” pipes, may need even larger mains, midrange pipes may only need one size larger on the pilots

Add 2 into 1 Pipe & silencer:4-5 sizes larger on the mains, 0-1 sizes larger on the pilots, adjust airscrews

Reeds
Add Reeds, Aftermarket reed cage, or Ported reed cage:Move needle clip one position leaner, adjust airscrews, 0-2 sizes larger on the pilots

Electrical
Add Degree key or Timing plate with advanced ignition timing:0-1 sizes larger on the mains, adjust airscrews
Switch coil wires (A lot of Banshees come from the factory with the orange positive wire on the “-“ terminal of the coil, and the black ground wire on the “+” terminal of the coil, switching the wires would put orange on “+” and black on “-“):0-1 sizes larger on the mains, adjust airscrews
Add Aftermarket ignition system:4-8 sizes larger on the mains, adjust airscrews

Compression
Add Coolhead with smaller domes or shave stock head:no change
(be advised that your octane requirements may change)

Miscellaneous
Overbore:no change
Re-ring pistons:no change
Forged pistons (stock crown, port timing and pin location):no change
Weld crank/rebuild crank:no change
Lighten flywheel:no change
Rewind stator:no change
Boost bottle/aftermarket intake manifold:no change
Clutch/transmission:no change

Elevation
For every 1500-2000’ above sea level, add to above:1 size smaller on the mains, adjust airscrews
For every 1500-2000’ change in elevation after jetting is dialed in:1 size smaller on mains for higher elevation, 1 size smaller on mains for lower elevation, adjust airscrews

Temperature
For 60-90 degrees F:no change to above
For every 20-30 degrees F colder than 60:1 size larger on the mains, adjust airscrews
For every 20-30 degrees F warmer than 90:1 size smaller on the mains, adjust airscrews
For every 20-30 degrees F temp change after jetting is dialed in:1 size larger on mains for colder temp, 1 size smaller on mains for warmer temp, adjust airscrews

Humidity
Very low humidity to very high humidity:0-2 sizes smaller on mains, adjust airscrews
Very high humidity to very low humidity:0-2 sizes larger on mains, adjust airscrews
 

Premix Ratio
32:1 ratio:no change to above
Higher ratio (40:1, 50:1, etc.):0-2 sizes smaller on mains, adjust airscrews
Lower ratio (20:1, 24:1, etc.):0-2 sizes larger on mains, adjust airscrews

Example

Your Banshee is bone stock, 32:1 premix, you’re at sea level and it’s 60-80 degrees.  You add a K&N air filter, remove the airbox snorkel, remove the airbox lid, and mount Pro Circuit pipes & silencers.  IF your current jetting is 25 pilot, 200 mains, start by going up to 340 main jets (14 sizes larger; 8 for pipes, 4 for K&N, 1 for snorkel, 1 for airbox lid), 30 pilots (2 sizes larger for the pipes), leave the needle clip in the stock location, and start with the airscrews 1.5 turns out.  If you got some reeds at the same time, everything would be the same except you’d start with the needle one clip position leaner than stock.

[sickOne]

thanks everybody for the info I would be ordering some jets and spark plugs this weekend and see how that goes, this is gonna be my first time jetting so hopefully I don't screw it up..lol

[BUILDER]

It is really easy to do just make sure you only take one carb off at a time and only pull one slide at a time. You pull them both and you may end up putting the slides back in the wrong carb so if you have never done it before it is easiest just to do one side finish it and move on to the other side. It is as easy as getting carb off pull 4 screws out of the bottom of the bowl remove the main jet that is right in the middle sticking out at you and putting the new jet in. Make sure you use the little brass washer under the main jet when you install the new jet. Just bolt the bowl back on install carb and ride the hell out of it.