The carb settings following are starting points for the High Torque engine:

For the WT668 it is 1-7/8 on the low and 5/8 to 3/4 on the high

For the WT603 it is 1-7/8 on the low and 1 to 1-1/8 on the high

For the WT644 it is 1-3/4 on the low and from 7/8 to 1 on the high

For the WT488 it is 2 on the low and 1/3 to 3/4 turns on the high

For the WYK33 it is 7 turns on the low and 1-3/4 on the high

When setting your carburetor, you must realize that the low speed needle needs to be set so that the engine sounds rich and dirty when it is on the stand.  It will even sound this way when it is in the water when you are running at low speeds.  If you try to set the low needle so the engine is real crisp and responsive, in other words it sounds really good on the stand, this is too lean of a low setting and it will bog in the water when you try to accelerate.  For the most part you can set your low needle to our recommended settings and just leave it there and not adjust it at all. 

 The High Speed needle is another story.  You will need to move the high needle to find your best performance.  If you get the high needle too lean, you will have less mid range torque. A slightly rich setting gives your engine more torque. Too lean of a setting on the high speed needle will also make the engine flatten out on the top end.  

FOR OLD WYK33 CARBURETORS BEFORE 6/15/11, not applicable after that date

The low speed needle of the WYK33 carburetor is in the center of the carburetor barrel.  Use a small precision flat blade screwdriver to adjust it. You must use Loctite #222 on the low needle threads. Do not use any other Loctite other than #222.  If you do you may never be able to move the low speed needle again.  Make sure you clean all of the threaded surfaces with contact cleaner or carburetor cleaner and dry them before you apply the Loctite. If  you want to adjust the low speed needle after the Loctite has dried, only move it a little bit in the direction you want to go. Do not run it all the way to the bottom and then back it out, this will wipe all of the #222 Loctite off and the low needle will be loose again. All modified WYK33 carburetors and replacement bored out barrels come from us already Loctited and the low needle is set at 7 turns out. 
With this carburetor, you can set your low speed so the engine is fairly clean and responsive.  Don't over do this, lean the low speed needle so the engine just cleans up and no more on the low end.  If you get the low too lean, this carburetor will bog also (see info above on the butterfly carburetors).  You also may have difficulty shutting the engine off if the low needle is too lean.  Usually opening and shutting the carburetor quickly will allow the engine to quit.  If you want to have a reliable shut off, hook your throttle linkage to a kill button.  You should have the kill switch hooked up to your radio anyway, it is the safest thing to do.  Setting the high needle has the same characteristics as the butterfly carburetor info above.  See below for instructions for Loctiting the low speed needle.

This is where to look to see what model butterfly carburetor  you have.  Note the WT is the type of carburetor and the model as shown here is the 644.  The carburetor type will be on the top and the model will be directly below the type.  The number to the right of the WT is NOT relevant, ignore this number.  This is a WT644 carburetor in the photo.

The carb settings following are starting points for the Pioneer shipped after 6/15/11

For the modded WYK33 carbs, the 26cc Pioneer     High 2-1/2 turns     Low is 2-1/4 turns
                                                        the 29cc Pioneer     High is 2-1/2 turns    Low is 2-1/4 turns,
                                                                                            see below for settings for older carbs

The low speed needle of the WYK33 carburetor is in the center of the carburetor barrel. Use a small precision flat blade screwdriver to adjust it. The newest versions of the modified WYK33 carburetor use a longer spring under the low speed needle. No Loctite is needed with this longer spring. With this longer spring the starting setting for the low speed needle is 2 turns out.

+2 mm Stroker Pioneer 30.5 cc Needle settings.

Very important, you will notice that you are going to probably need a lot leaner needle settings with the +2 mm Stroker engine.  2 to 2-1/2 turns out is not unusual at all.  As you continue to lean the high needle it will get faster on the top end, if you lean it too much it will start to flatten out and you will need to back up a little.  The tricky thing is if it is too rich, it still sounds and runs fine.  It just does not make as much power as it could if you set it right.  This makes it a little bit hard to nail down because there are no obvious signs that you are too rich.  The bottom line is don't worry about what the turns are, just set it so it goes the fastest.
As far as the low speed needle goes, set it so you have your absolute best launch from a slow idle.  If it is set right, it will just snap right out of the water when you pull the throttle.  If it is too lean or too rich it will be boggy.