well would it help any? (300ex)

 

come on some body most know if this works

 

As strange as it sounds, many times taking the lid off makes the engine go flat on the top end - even if you attempt to jet for it.

A better solution is to cut a hole in the lid, preferably behind the filter. Try 2" diameter and go from there if you want to mess with it.

 

is that 2 in. or 2 cm.

 

Inch

 

ok dokey

 

Don't mess with holes unless water is an issue. Get rid of the lid and increase you main jet. More air + more fuel = more power. I'm not familiar with a 300EX (I had a 400EX), you might have to raise the needle as well. Proper jetting will increase your top-end. My 400EX would climb hills without the lid that it couldn't with the lid on and 4 1-inch holes.

 

wat do u mean unless water is a issue

 

Tuning is an issue (and I'm not talking about jetting). You don't completely remove the exhaust for the same reason. Sometimes getting "more air" means using your head and not just ripping off every potential source you think may be a restriction.

Removing the lid on a 400ex has been shown on the dyno to kill top end (or should I say, peak) power on most configurations unless they are built to the point that they become restricted with a hole in the lid (not likely in all but the most extreme cases).

Personal experience with timed drag racing 400EX's, 250X's, and 300EX's has also confirmed this. We couldn't get the bikes with completely removed lids to run with the bikes that we cut holes in no matter what the jetting. The bikes with completely removed lids also "felt" noticably flat on top.

That said, removing the lid will many times show an increase in midrange (which is probably why you climbed hills better) - but again, at the expense of top. From what I've found you can get the same (or more) mid-range gain without the loss of top by cutting a properly sized single hole (again, behind the filter so that debris, water, etc can't come in direct contact with the filter itself - I personally run a "port" in the hole as well). Finding a "properly sized" hole may take some experimentation.

This is also one reason why every modern automotive vehicle on the face of the earth uses a tuned airbox and and runner system instead of an "old school" open air cleaner.

I know that to some, this won't make sense - but sometimes it takes a lot of trips to the drag strip and getting beat by a machine that shouldn't be beating you for one to become open enough to listening to something that doesn't fit "conventional wisedom".

 

If it is jetted and u have a K&N when u take it off u get more power that how mine is