It sounds to me like you are running lean when putting on the K&N filter, but you should experience the same without no filter on the machine. It doesn't make any sense that the machine would run worse with the filter on compared to the stock or no filter. If that is the case, then it would appear that the K&N is restricting air flow, therefore causing it to run rick, which is very unusual. When you say you 'soaked' it, do you mean to clean it? After you clean a K&N filter, you have to reoil them. And when cleaning them, I would only recommend using the K&N air filter cleaner, you spray on the ouside, let it sit for several minutes and then run warm water through from the inside to the outside to wash it out. The let it dry and spray on the K&N air filter oil....

 

There is no way you are running lean. If you were running lean the machine would usually rev, not bog. Something is restricting airflow, that's simple. Are you using K & N oils on the filter? Something is wrong with the way you oiled your filter or the actual filter. Do you have a way to try it on another machine?

 

Are you putting the air box lid all the way back on? The reason for the question is I put my K and N on and tried driving with the lid off. BIG MISTAKE! It didnt die but it felt like it was going to.