i have an o3 fiddy modified air box and spark arrestor removed and now my bike smokes. i took out the spark plug and it is black. With this setup it should not be running rich or should it? i thought it would be lean. throttle response is good and bike seems to run good. any help would be great. i have not adjusted the carberator at all.

 

NOT UNLESS YOU MIXED UP SOME PREMIX, PUITTIN THE KLOTZ IN THE FIFTY WILL MAKE IT SMOKE EVERY TIME

 

do u change ur oil

 

I had the same problem when i first bought my fiddy.
If you can, take a look at the piston. There should be 3 sets of rings. The last set should have 3 rings in it. 2 straight ones that sandwich a wavy ring.
If the 2 rings are not there, it will make it smoke like a beatch.

Hopefully its something simple as you put the wrong oil.

 

Too rich jet that bad boy