How about needle position, and a plug check? If he didn't do this, and PROPERLY do it, he needs to.

And yes, often the pilot needs to be changed with adding pipes to a Banshee.
Needle position is also VERY important.

The main jet only controls from 3/4 to full throttle. Also, just because those jets came with the kit does not mean they are correct. Sounds like somebody needs to read up on jetting.....

Read this......Carburator theory 101

Reading sparkplugs

Another great plug reading guide



Here is my recommended method step by step on how to do a plug check.
Print it out and give it to your friend, or take it along when going to different riding places in different weather conditions.

Setting up your ATV for the correct jetting in ALL circuits...............................
FIRST OFF MAKE SURE THE FILTER IS CLEAN AND YOU HAVE FRESH (PROPERLY GAPPED) PLUGS ON HAND!!! Do NOT assume they are already properly gapped!

Find a wide open area where you can go full throttle for at least 10-15 seconds.

PILOT CIRCUIT:
You turn the air screw out till you get a crisp throttle response from off-idle.

If you have a hang-idle, you are too lean and need to either turn the air screw back in, or go to a larger pilot jet.

If you open up the air screw, and it still does not improve the throttle response, try going to a smaller pilot.

Adjust the pilot circuit first using the air screw and pilot jet as described above. You want a crisp throttle response with no bogging.
You can drop the pilot jet size till you get a "hang idle" (this is where the motor does not come down from a high RPM very quickly). It means you are LEAN.

You can adjust from there by either turning IN the air screw till the idle settles down, or if you have to turn in the air screw too far (less than one turn out) then move up to the next size pilot jet. You want a crisp throttle response without the hang idle.

You can do the above while in neutral, and letting the bike idle.

Next you want to take the quad out and get it up to operating temp.

When warm, shut off the quad, pull the plugs and install FRESH WHITE PROPERLY GAPPED ONES.

NEEDLE/CLIP POSITION:
Now, we are going to check the midrange also known as needle position.
Take the quad out and hold it at half throttle for at LEAST 10-15 seconds.

While still at 1/2 throttle, pull in the clutch and kill the motor at the same time. Leave your thumb on the throttle holding the same position till you roll to a stop.

Pull the plugs and look at the color of the INSULATOR (the formerly white ceramic portion).
Look down into the insulator between the ceramic core and metal outer body.

You want to see a light tan to paper bag brown color on the insulator.

If the insulator is LIGHTER than this, you are too lean.
Go DOWN one position on the CLIP. This will effectively RICHEN the mixture of the midrange.

If the insulator is DARKER than this, you are too rich.
Go UP a position on the CLIP. This will effectively DROP the needle and LEAN out the midrange.

MAIN JET:
Once you have the midrange set, you will go for the FULL THROTTLE run. This will determine the MAIN JET size.
Once again, following the procedure as above, get the motor warm and do a FULL THROTTLE run.

Hold the throttle WIDE OPEN for 10-15 seconds.

Pull in the clutch and kill the motor at the SAME TIME. Keep the throttle pinned till you roll to a stop.

Pull the plugs and look at their color.

Use the same colors to guide you for main jet selection.

Dark brown to black = too rich. Go down a size on the main and continue to do the checks like this till it is the correct color (light tan, or paper bag brown).

White to very light tan = too lean. Go up a main jet size and do another plug check. Continue to go up in main jet sizes till you get the proper plug insulator color.

Now you are jetted correctly.

 

Very informative post 2fun [img]i/expressions/face-icon-small-smile.gif[/img]

 

spark plug reading

heres another link to spark plug reading

 

omg this is too funny