Water in Airbox

[Johnny Depp]

I believe the "pre filter' on Knight's bike is just that. Not meant to replace the original, only supplement it by slowing down mud and water splashes.

I have the same water buildup in the airbox even when just washing the bike. I don't know if it will help but i took out the bleeder valve and slotted it much more with a knife. It is just like the mouthpiece on a Camelback, I slot them out too so they will flow better.

Motocross bikes frequently cut round holes in the airbox to let in more air for power and cover them with a screen. You could always try it with the sidecover off to see if it helps power. By the dust pattern on the filter it is obvious that the air is primarily coming from one small spot which is bad for power and also filter life.

I also found both of the round seat to frame bumpers had come off the seat base and were in the bottom of the airbox after this weekends MX race?

[Magile]

The air will flow though the path of least resistance, so the majority of the air will flow through the areas without points first as there is the least amount of foam (resistance) to travel through. When that area gets dirty enough to increase the resistance, the air will start to flow through areas with a little more foam until the filter gets dirty enough that the air is flowing through the little points of the filter. At that point, the filter will be working like your stock filter with air flowing through all of the filter. In reality, this design effectively DECREASES the usable surface area of the filter until it gets dirty enough while increasing the cost of the filter.

If the little spikes were all duplicated with little holes on the inside of the filter so the thickness that the air needs to travel through was pretty much the same everywhere, than this filter would increase filter surface area and might be worth the extra money.

My 2 cents.

Gotcha. I wonder how the thickness of the thinest part of the FunnelWeb compares to the stock filter?

[bazza]

I removed the bung from the bottom of the airbox to allow water to drain freely. I then cut up an old air filter and wedged it underneath the air filter to stop water ingress. I cut another small triangle to fit in the lower corner of the side cover to do the same job. I remove these and the filter and fit a filter cover for washing and any gunk in the bottom of the airbox can then flow out freely.

[DaddyTJ]

I just cut the slit in the rubber piece larger and don't have any issue now with water building up in the air box even when washing the bike. I always wash the air box each time when washing the bike.