needle carb setting. kinda weird

[meatgrinder]

so guys, im almost finished with my pk80 btr build. just waiting for the springer fork to arrive & just ran to a weird problem. i fabricated a custom air filter with lotsa holes like this one made by silverbear except mine is made from a vintage kiwi shoe polish can

http://motorbicycling.com/showthread.php?t=17262

so while running, noticed that the bike is kinda sluggish (still running the 20:1 mix) and inspected the NT speed carb for the needle setting and found it to be on the factory setting, 2nd to bottom and tried to raise the needle to the middle and the bike ran awful! 3/4 throttle and the motor would die. tried raising the needle one more notch (2nd to top) and the bike keeps on bogging down. anybody heard of too much air? do i need to somewhat compensate the gas for the too much air being sucked by the engine? btw, sealed and checked all the possible airleak spots but found none.. any help would be much appreciated!

 

[MotorBicycleRacing]

Go back to the standard air filter and see how it runs.

 

[Ilikeabikea]

Try a 32:1 mix. I bet that will make a world of difference......

 

[crassius]

tuning an engine that has not yet run in is pretty much useless - live with it till it's ready to run right

 

[maniac57]

Raising the needle is just making it richer. Drop to the second from the top slot and let it break in fully (3-400 miles) Then you can see what it wants.
Every single engine I've ever bought was blubbery rich from the box. The chinese do this to minimize failures under warranty.
Your extremely rich oil ratio also contributes, try 32:1 like ilikeabikea said.
Personally, I run 40:1 from the start and have good results.

 

[meatgrinder]

thanks for the helpful info guys, maybe im just gonna live with it and tune it once broken in. i'll also try 32:1 mix for my next tank. im gonna use a "76" 2 cycle oil, non synthetic and see how it will turn out..