as stated above... i remember seein some1 post a pic of the slide with the correct hole to be drilled for the slide mod... i had no idea where to begin lookin for it, was hopin some1 may have it on their pc or know where it is on the net....
TIA

 

i dont have a pic but its the one that is not in the center..... there is only 2 holes in it right? its the one the the side.. off center.

 

Here is a pic posted by Richt a while back. I think this is the one that you are talking about. If not, it still should give you the info that you need. BTW, I had the same question when I was doing it.

Good luck with your mods.

 

big thanks... thats exactly the one i was lookin for.....my pipe should be in soon.... when it arrives bein the lazy turd i am, im takin it to the shop to get jetted (dropped my rims off with a new set of kendas to get mounted today)...... along with the k&n and backfire screen removal i am going to have them drill the slide while there jetting it for me.....as a sidenote.. they also have a dyno theyll use to jet it so ill have a report on HP with my mods when i get it back..... hopin to have it all done within a month finances allowing...

thanks again.
(saved the pic to my pc)

edit: just to make sure, what size bit should be used?

 

bit size for slide vent mod = 7/64"

If you are going to pony up the $ for the dyno, how about see if they will do a "before" one as well. I don't think we have seen any true apples to apples comparisons of a "before" and "after" on the same bike.

BTW, is the K&N fire retardant. I am surprised a shop would remove a backfire screen with the potential for liability and all. I am interested in doing this myself, but I just put in a new Uni about 2 months ago. I hate to ditch that so soon.

Good luck with everything. We will look forward to seeing your dyno data.

 

welp as to a b4 run, i already have some mods done so it wouldnt be a stock measurement... and i may be mistaken but as i took it they always use the dyno for rejetting machines, tho i may be wrong. as to the K&N being fire retardent .. it isnt, but it is MUCH less likely to burn as a foam filter would be as its fabric... i remember reading some1 highly recommending the K&N for backfire screen removal at the minimum... (cross ur fingers) i dont foresee them giving me problems removing the screen if its what i wanted and they warned me. i dont see how they would/could be held liable. (also helps that a good friend of mine works in the service department ;> )

 

I agree with you 100% that if they warn you and you still ask them to do it then they should not be held liable. We all know that there are a bunch of people out there that don't see it that way, though. I continue to be floored at some of the crap that people sue each other over.

Have a Merry Christmas. Good luck with the mods.

 

I called my local Kawi shop asking about the TwinAir Backfire filter and he said he couldn't get it anywhere, and he suggested K&N as well. He said the wire will prevent the filter from burning because it draws the heat off from the cotton. The K&N website says the KLX250S modeldoes not have an "inner screen", but I can't find anywhere what the "inner screen" is for.

Anyway, I called a local Yamaha shop, and he says he can get the TwinAir BackFire Screen (Twin Air Part # 152313) from Parts Canada (Parts Canada Part # 700758). (I think the Kawi shop could haveordered from the same place, they're just lazy ... the Yamaha dealer is closer to me anyway! )

This whole backfire airfilter thing started up the day I finally got my UNI filter. Luckily, I didn't open it up yet, and I'm returning it tonight.

A before and after dyno run would still be informative, even if your bike already has a couple mods. It would probably highlight the performance gains just from rejetting and opening up the exhaust. Drilling the carb slide probably wouldn't show up on the dyno, since it relates more to throttle response as opposed to torque and horsepower. That's just my guess, though.

Good luck with the mods!

Mike

 

Very bummed this thread was never followed up on!

 

YYY.GUY.....you're on the right track for sure! Someone much more knowledgeable than myself suggested the exact same filter for the '09 KLX250S:

"part number 152313 air filter (FR) fire retardant Yamaha YZF YZ250F/450F 97/04. This isn't a exact fit it is a little larger than the stock filter but it works well."

I have not tried this filter myself but this info came to me from a very reliable source.