I did this last year, I enlarged the orignal hole and put the stock snorkel rear facing and KDX front facing. I was playing around last weekend and pulled both out. The noise and vibration on the seat were too much. Throttle response was also delayed on the bottom end. I put them back and the CV carb is much happier, no noise or vibes.

 

so you had one hole for both snorkles? How did you keep them both in there with limited support of the snorkles?

 

I trimmed the stock snorkel to butt up against the KDX snorkel. The snorkels are back to back and are held by three sides so they fit pretty well. I will try to get a picture, snow and ice tonight so hopefully this weekend.

 

What was the logic of one hole versus 2 holes that hold on 4 sides like a factory snorkle?

 

The logic is keep it simple. The snorkels fit very well and are slightly difficult to get installed. They are rigid enough that being held on three sides is more than enough. Did not make sense to cut a hole over the filter and then have to cut he bottom off the snorkel. The inner part of the snorkel acts as a resonaotor to help with noise and also keeps incoming air from hitting the filter directly. Useful if riding in heavy rain or soupy trails.

 

hi. My first post here.

I have the fuel injected version of the KLX250S (asian country).

First time I rode the bike , I wondered where the power was. It felt dead.

Removed the air box lid today. It totally woke the bike up . Am very pleased.

Are there any EFI tuning tips for this bike ? Most of the posts here concern the carb'ed 250.

thanks and great forum.
.

 

Ah ok, makes sense, i was wondering if you were going to say you didnt want water dropping on the filter, which doesn't make sense. The surface area of the stock snorkle is over 3 inches, the drain hole in the bottom is 1/4". Doesn't take a PHD to do that math. If water comes in the snorkle, in quick order the airbox will be full, submerging the filter.

 

But what if you are trying to suck in 250cc of air 83 times a second (20 liters per second) at 10,000rpm for example? (and at only a fraction of that 1/83 second btw)

:headscratch:

I know the air scoops on F1 cars aren't overly large-but there's nothing to impede the air's movement to the scoop like there is with an air box buried beneath a lot of stuff

Video fun:





(watch the end of this one for an example of the engine at hi rpms)

 

True, but if enough water gets on the filter, it could run through the filter taking some grit along with it and get sucked in the carb. Maybe not likely, but could happen. Just sayin' there was a reason too for the snorkels to run behind.

 

Those are crazy cool videos! The spark plug sounds like a musical instrument, it's crazy how for each 1000rpm it seems to raise a whole step on the scale (for those who don't know music A to B, B to C etc.)