Has anyone ever heard of K & N filter making a bike run rich??? Here is the story. My foreman where I work has a Yamaha royal star (read arm chair that farts) that he bought second hand a couple of years ago. it had aftermarket pipes already on it. A couple of weeks ago he replaced the genuine air filter with a K & N. Now it only takes a couple of days to foul the plugs. I'm talking soot from an over rich mixture. Sounds strange to me. Any ideas???

 

it wont run rich,it could run lean.the filter by itself wont cause a problem,he may run lean with the pipes and the filter together tho.

 

Exactly my point. But since he put in the filter it's now running rich. I know nothing about the bike & how they are set up so I'm wondering if there is anything he may have inadvertently altered?

 

Hi:
I'm trying to find answers to the same problem. 1978 CB550 k. I just put cone fillters on it and now it will move only with the choke half out but has clearly lost power and throtle response. I'm afraid to pass anything else on wheels. I assume there is now way too much air. I re-set the floats, and the external air jets and gotno change. Now it barely idles unless the choke is on and quits when I try to pull away from a stop.


O_C