New to me banshee need help

[MGRAM]

Hi new to the site and new to the banshee but not new to quadding, i have a 2008 yfz 501 and a 2007 raptor 700 modded to the extreme on stock bore and stroke, but just got my hands on a 2003 banshee 421, but unfortunetly previous owner had no clue how to tune it, so this where my problem lies since i'm at square 1 and not sure where to start in tuning this machine, starts with 1 kick runs strong besides the feeling of needing a tuning baaaaad, has a bad bog top end and doesn't hit as hard as it should IMO

The current mods on the 2003 banshee are as follows

trinity big bore/stroker kit with 421 cc's compression is 150psi both cylinders(not sure what domes it has or pistons exactly)

Trinity timing plate currently set a 4 degrees

Dynatek programmable ignition(set at stock)

38mm PWK carbs

Trinity billet manifolds

V-FORCE 3 reeds

Trinity billet stator and clutch covers with lock out clutch

K&N pod filters with outerwears

FMF GNARLY pipes and FMF silencers with fresh packing

 

so basically not sure where to start with this, what jets are recommended for this build, mixture screw turn out, timing plate and ignition set to and so on, sorry but a lot to ask i know lol my elevation is 2500' above sea level, haven't checked current jets yet since the quad is less then 2 weeks old to me

 

Thank you in advance for any help and advise for making my banshee run perfect

[volcrano]

what type of riding do u do?me personally i would set the timing to 0 and advance the dynatek to the 4 degrees advance.i would have to say those gnarlys are definately holding back power potential.they are a low mid pipe.ive heard good things about the trinity stage 4 pipes and i believe they were built to work well with the 421.i think a dude even has a set for sale in the for sale section.what is ur jetting.if ur bogging up top u need fuel.if ur sputtering ur too fat.so i would see what jets are in there and start going up.what do the plugs look like?get ur main jet richened first,in doing so it will also richen needle settings to an extent and u should start to feel a nice hit in the mid and pull up top.

[LS3 Machine]

Welcome to BHQ! Im pretty new here, but Ive been tearinig into my Banshee and I just re-jetted my PWKs. I got a lot of great advise here, and I feel Im actually getting good at the jetting process. The Banshee is easy to work on IMO, as this is my first experience with adjusting carbs and jetting, and it's not hard at all.

 

First read the jetting forum FAQ sticky about what is jetting.

Make sure the carbs are synced up good before you start messing with the jetting, also make sure you have a good mix ratio (most like around 32-40:1), of fresh premium gas, and a new pair of properly gapped spark plugs installed.

 

 

1. First pull the main jets and get the size. It really easy on a PWK, you can just pull the carb off the manifold, turn the carb upside down (gas will spill, so have a rag underneath it), and unscrew the 17mm plug in the bottom of the carb bowl. Then the brass jet looks like a hex nut with a hole in it. I use a jet wrench (FAST sells them cheap) to remove the jet, or you can use a real small socket wrench (Maybe 4mm???).

 

2. Once you know the size, order up some jets 2-3 sizes bigger and smaller. Turn your air jet screws all the way in, then back out 1.5 turns. You can do this part when your syncing.

 

3. Once you get the new jets, go up one size, test ride the bike... if it gets better, you know your heading in the right direction (it may only get marginally better on one jet size). If it gets worse, you probably went in the wrong direction.

 

(I wouldn't mess around with needle clip location until I had both the top end and bottom end pulling smooth)

 

4. Check out the plug chop info available in the jetting forum.

 

Here is some troubleshooting info I got of the net:

 

DIAGNOSE WHICH AREA YOUR PROBLEM IS LOCATED

 

1. Start to Idle - Replace Pilot Jet

 

2. Idle to Mid Range - Needle Jet Adjust Clip

 

3. Full Throttle – Replace Main Jet

 

 

 

BIKE TOO RICH

 

Smaller Size Pilot or Main

 

Adjust Air Screw Down or in makes Minor Adj.

 

Moving Clip on Needle Up

 

 

 

BIKE TOO LEAN

 

Larger Size Pilot or Main

 

Adjust Air Screw Up or Out makes Minor Adj.

 

Moving Clip on Needle Down

 

 

 

 

Good Luck and keep us posted... we need pics of your bike as well.

Remember to come here if you have questions.

[MGRAM]

Thanks for the reply's guys, i ride trail and some sand dunes, but most of my trail riding is done by my raptor and bought the banshee to have to 2 stroke fun I haven't checked out my jet sizes jet but will pull them off later today to see what i have and check the plugs and go from there and will get it all cleaned up and post some pics. I have been running 32:1 mix, with 94/111 race fuel mix with amsoil interceptor oil

[MGRAM]

Finally checked my jets last night

162 main

55 pilot

[LS3 Machine]

Finally checked my jets last night

162 main

55 pilot

 

55 pilot is very big... Especially at 2500 above sea level. I would imagine you might have a bit of a stumble just above idle? No wonder it smokes. definitely consider going down to a 50 or maybe a 48 (possibly smaller even), when it pulls clean from idle to 1/4 throttle, you have the right size pilot jet. The main seems big to me as well.... Im not sure what you need for that setup, since its quite a bit different from mine. Im sure someone with a similar setup will chime in. Post in the shout box for help if necessary. I would buy some jets in each increment, 3-4 sizes smaller than what you have, sync the carbs real good, get fresh gas and plugs, and go to town on it. Good Luck and keep us posted.

[MGRAM]

It is a little boggy off of idle, sounds like I'm gonna be buying lots of jets tomorrow lol, can't wait to get this thing running a 100%

[MGRAM]

I finally got around to jetting my banshee, I thought it was running lean with the way it was running so i put in 172 main jets and made it worse so i added 155 mains and it was a major improvement in the right direction, i ended up with 150 main jets since the "flat" spot in top end wasn't improving, i'm thinking the flat spot is being caused by the FMF Gnarly exhaust since they are a low end pipe. I still have to adjust the pilot jets and the needle but not sure if i should upgrade my pipes to another set

[LS3 Machine]

I finally got around to jetting my banshee, I thought it was running lean with the way it was running so i put in 172 main jets and made it worse so i added 155 mains and it was a major improvement in the right direction, i ended up with 150 main jets since the "flat" spot in top end wasn't improving, i'm thinking the flat spot is being caused by the FMF Gnarly exhaust since they are a low end pipe. I still have to adjust the pilot jets and the needle but not sure if i should upgrade my pipes to another set

 

 

Good for you. Keep us posted on how its running. I dont think there should be a flat spot? Is it in the mid to top, or just the top end? I wonder if at your altitude if maybe one more size down might help? The higher the altitude, the smaller the jets u need (less air at altitude equals less fuel required). If your mid range is hesitating, you may need to lower the needle a bit (by raising the clip).

[MGRAM]

Pulls strong all they way to the top and then just seems to peak out at the very top having a flat spot in power, was thinking of different pipes to help, I have some 145 jets but didn't want to go too lean

[LS3 Machine]

Pulls strong all they way to the top and then just seems to peak out at the very top having a flat spot in power, was thinking of different pipes to help, I have some 145 jets but didn't want to go too lean

 

Your at 2500 ft, 145 might be just right. I would give that a try. Just dont wail on it all day if it gets worse. I think some people try to blame their bike no7 running perfect on pipes, when in reality their bike isn't tuned right.

[MGRAM]

I will throw the 145's in this weekend and will report back, thanks again for the help it's much appreciated

[MGRAM]

Ran the 145main jets and 48 pilots and quad ran really good but could tell the top end was lacking, bottom end was awesome. So I ended up selling my gnarly pipes yesterday and went to purchase the shearer big bore in frame pipes but seems like I made a mistake with going to the bansheedepot.com anywhere else to purchase the shearer pipes that deal with paypal?