I have a Stock 03 660 and I just got a HMF slip on and K&N filter .. I was wondering if it was good to cut the airbox lid a little bit and then put holes in the side of the airbox to get more air and what jetting I should run with this combo .. Thanks for the help ....

 

<div class="FTQUOTE"><begin quote>Originally posted by: YamahaRiderOnly

I have a Stock 03 660 and I just got a HMF slip on and K&N filter .. I was wondering if it was good to cut the airbox lid a little bit and then put holes in the side of the airbox to get more air and what jetting I should run with this combo .. Thanks for the help ....</end quote></div>

If you cut your air box too much you will be running lean and somehow have to close it up again. Second thought comes to mind is water, how will you keep it out.

Jetting is determined by the color of your sparkplug. You make top end runs and at your fastest speed you kill the engine and slip it in neutral and stop and check the color of your sparkplug.
The link below has some good Q&A for you to read.
http://www.dfn.com/benkaren/jetfaq.html


Also check in the Arctic Cat forum for 'Air-jetting' there is a good solution for your air box if you are running rich. And it is a cheap fix, flexable and reversable.

 

Anyone else have a Comment ?

 

Just cut a square out of the lid. Take off as much plastic as possible without messing up how the lid holds on. I belive the rappy comes stock with 140-145 mains I would start with 155-160 and see where you are at, might still be a little lean but its a start

 

i have a 660r. i just leave my lid cover off when i want to race my buddies. and it does help a little.