My Pro-flo set up and stock air box have created a turbulence problem and I have had too lean my needles accordingly (many of us have done this). Anyone have an idea of how too get around the problem while still using the pro-flo?

 

Gary- you having part throtle problems?? A lot of guys have gone to a set-up like sixsixt's (get rid of air box completly) and not have any problems. I have had my carbs off at least 100 times over the last few years and one thing that always helps is to blow out every passage. They are lots of passages that can get blocked up.

 

Thanks for the response. I had a needle hesitation when I installed the pro-flo and removed the lid. I leaned the needle too compensate for the obvious turbulence problem. The carbs were cleaned at that time too make sure the problem was the pro-flo and no lid combo. I need the air box since I trail ride and it keep most elements out.

 

unless you are soaking up water that will be a big problem,but i trail ride too and not one thing of dirt has passed thru the filters...I also run sixsixts plate and love it...

 

Cv carbs work on the different atmospheric pressure between the motor and airbox side to activate the slides. I feel that when you increase the atmoshperic pressure on the airbox side, or quicken the pressure changes by removing the airbox or lid the slide moves too quickly. Richening 1/4 to 1/2 too much and causing a bouncing condition. Some people modify the slides by drilling the lift holes bigger (bottom side of the slide) although I am not sure on the principle of that. I feel yamaha made the flaps in the airbox snorkle to compensate or "tune" the carbs.

I thought of maybe a piece of foam filter in the tubes that go back into the boots from the airfilter may help stabilize the pressure changes back to somewhat normal.

 

I found out that using the stock airbox with out the lid will cause a lot of turbulance & like was said the CV carbs don't like that!!
What is your jetting?? DJ recomended 165~170 for removing the lid.

I got the Adaptor like sixsixtys from Jays shop, It flows a ton of air without the turbulance, I'm going to try to build a splash guard for it, but I don't ride in the wet much so it's really not a problem.

I wonder if the after market airboxes have the same turbulance problem??

 

according to ppd they're airbox runs better than running it without the box. they've dyno'd it and swear by it. i have'nt installed mine yet...but i will report back when i do

 

With the lid on low speed intake velocity is gonna be higher.....this is gonna create more suction too open the slides up quicker. With my lid off......with less low speed intake velocity...I had too lean my needles too compensate for the slower moving slides. If the slide hole is larger.....this would actually let the slide raise slower. Maybe a larger vacuum line or maybe a 2 into one vacuum line setup per carb would work better? Two vacuum lines coming from the intake and back too the original single nipple up top. What are you guys thoughts?

 

Since using my adapter throttle response is alot snappier and low throttle settings seem spot on. Maybe getting rid of the box and using a splash shield like MOOSE said would work for you. I have an adapter that you can use the pro flow filter on if you want to try it.

 

when i first removed my lid and re jetted i was getting some hesistation and my throttle response was not what i thought it should be but after i drilled a one inch hole in each side of the air box and one in the back my performance was back.i am assuming that i gained my performance back by eliminating at least some of the turbulence caused by removing my lid ,either way it worked.