So, I am to understand that, since my "vacuum operated slide will not open with out it, period", and, my DS only makes it up the steeper hills without opening the slide, and my bike will have less HP with the Box lid off, then, I need to reduce my horsepower to climb even steeper hills. Hmmmmm?

I'm not disputing what MisterHP says that he saw on the dyno, but I know that my 2003 Baja hauls. JohnnyRaw is running without lid or snorkels and his is seriously fast too.

Maybe the older ones had too stiff of slide spring. I know I have seen two different springs that fit these. And some may have too high of a spring constant. Once again, it is not vacuum in the venturi, that opens the slide. It is the air speed. The air speed causes vacuum in the slide boot. It seems that the best way to maintain air speed is to make sure the exhaust is not too restrictive.

 

I would have to agree with you on that one.[img]i/expressions/face-icon-small-cool.gif[/img]

 

We have been running our stock DS's without the air box lids. Partly out of laziness, as we are at 6,000 ft
and with the lids on they run rich. Lid off, they run great, and no need to rejet. If we go down in elevation we have to put the lids back on or they run like crap.

So the question is: Would they run better with the air box lids on and slight rejetting? like maybe just drop the needle a notch? Seems to me that more air and more gas = more power.