One of the first things I would like to do for my 05' is replace the stock filter with a K&N and outerwear. I know the bike runs a bit on the lean side so would I have to rejet if I do this or can I get away with it. It will be some time before I can get an after market pipe and I really didnt want to rejet till I got the pipe. I plan on riding in the dunes and would feel a lot better with a better air filter.

 

Get the NCVQ needle from the dirtbike and put it on clip3. Then put in a 45pilot and a 165 main and your set to go. Will take you less than 30 minutes to do all that. Much more power too!

 

Don't be a fool and put a K&N filter on your YFZ450. K&N filters let too much dirt into the motors. NONE of my Baja racing buddie use K&N filters as they are motor killers. Buy a Pro-Design foam or UNI Foam filter and rejet to 45 pilot, 172 main and go to the 6th position on the needle. Put a DUBACH pipe on it and remove the air box lid and install a "OUTERWEAR" air box lid top. Change the oil and filter after your first ride and check that the chain isn't too tight. Pull the swingarm apart and add "ZERK" fittings and lube it. ADD some swingarm and engine skid plates and break it in easy. If you don't re-jet right away you risk damage to the motor as they are way too lean from the factory.

Add a fuel filter, and remove the Carb to re-jet, it's easier that way.

Good Luck
GLWBEAR
glwbear@netmagic.net[img]i/expressio...mall-smile.gif[/img]

 

I agree....The K&N will add a lot of air, but I heard could cause problems if you run in sandy/dirty conditions. I guess their good for the racers that tear there motors apart a lot. These guys are sponsered, winning races/$$$$, so it's worth it for them.