K&N air filter

Would changing over to a K&N air filter (in the air box, not the pod type) change the way my engine breathes enough to require re-jetting?

Jim
1985 XJ700X Maxim X
32000 miles and climbing

 

I have one in my xj650 with a bunch of holes cut in the lid, along with the mac exhaust with even more holes cut in the baffle. Seems to run awesome and the plugs still read fine on stock jetting.

 

I've got a K&N air filter in the stock airbox, and a MAC 4-into-1 exhaust.
Factory carb settings were so lean it wouldn't run without leaving the "choke" on all the time.

Installed jet kits to a stage 2, drilled the slides for more air -- runs MUCH better now.

 

I have a K&N airbox filter on mine (simply because it seems you can't buy the stock paper one anymore). Plus I have had good results with K&N flters on my truck and plane and like the fact that they can be reused.

I did not notice any difference when installing this filter, my bike still runs and idles fine (although possibly 100 RPM lower maybe). I have not attempted carb adjustments thus far, however I plan to do color tuning and carb syncing in the very near future.

 

I did not note a change needed when I installed my UNI filter in the stock box. I don't suppose you should need to rejet but the spark plugs will tell you the story. Let your sparklers be your guide.

 

I switched from the foam UNI filter to the K&N in the stock airbox. (Bike was stock, with no other mods to fuel or exhaust.) Forgot to oil the K&N when I first installed it and the bike ran way too LEAN. Oiled the K&N as suggested and it now runs great.