Raptor Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
I have a raptor 686 high compression piston stage 2 hot cam etc. I bought the fourwheeler like this. it also has no airbox just a k&n and Pre filter My concern is that would having no airbox actually cause the motor make less power since it has no velocity going in I want to get the carbs set correctly on the dyno but I'm not sure if they can accurately jet carbs without any sort of airbox
 

·
Registered
Joined
·
80 Posts
If thats going to stay your set up then tune it that way. If your eventually gonna run an air box then put the air box on it first & then dyno it.
 

·
Registered
Joined
·
235 Posts
velocity is not the issue here...yes it can be jetted like that, but like he said, it needs to be set up like you will be riding it before jetting it
 

·
Registered
Joined
·
80 Posts
I want to, but Ive always been concerned about water & crud so i run the filter lid.
 

·
I am unique
Joined
·
22,621 Posts
I havent run an airbox for years either, I never worry about the mud, water or dirt, drive fast and leave it behind...............:)
 

·
Master of the Electron
Joined
·
15,074 Posts
No airbox = much more power. Good aircleaner = no junk in engine.

I've been without the airbox for 4 years. Just clean the filter regularly.
 

·
Premium Member
Joined
·
2,247 Posts
I have a raptor 686 high compression piston stage 2 hot cam etc. I bought the fourwheeler like this. it also has no airbox just a k&n and Pre filter My concern is that would having no airbox actually cause the motor make less power since it has no velocity going in I want to get the carbs set correctly on the dyno but I'm not sure if they can accurately jet carbs without any sort of airbox
You really haven't stated how the K&N filters are on the bike. I assume they are bolted directly to the carbs since you have inquired about velocity. You should be able to buy two of the factory rubber tubes on ebay cheap or a velocity stack (aluminum tubes) set up for $100 if you want, like everyone has said you will make more power without the air box just don't over jet the motor which may be your current problem. I'm not a big fan of no air box year around because we ride in quite a few deep water crossing areas. I do switch to velocity stacks in the summertime July-Aug for the ATV drag racing at the county fairs and my FCRs need about 5-10 more numbers on the main jets. My winter modified airbox jetting is close to the Kentucky humid summer velocity stack jetting.
 
1 - 9 of 9 Posts
Top