drilling holes in 650L baffle any help ?

3 replies to this topic
  • roadcam

Posted October 06, 2004 - 04:33 PM


I'm just too cheap to spend $300-$500 to gain 1 HP from my XR650L with an aftermarket pipe ( I'll just lose 40 pounds of beergut, and REALLY make an improvement ! ) ... would drilling a bunch of small holes in my baffle be of any help, without getting too loud ?

  • 4WheelingPlus

Posted October 07, 2004 - 01:26 PM


I am no expert but I have been researching this same sort of thing...

If you open or remove the baffle it does make the bike louder. I removed mine. You loose the whistle effect and get a deeper sounds.

I am told that you loose bottom end as well. I cannot say for certain as I have made several other changes and the end result is a crappy throttle response.

I have been "playing" with mine and it seems there is a certain combo of steps you need to take to improve the motor.

I haven't perfected mine yet so I can't tell you the exact combo. It does involve de-smogging, better air cleaner, and possible jetting changes in the carb.

Baja Designs is helping me right now with my jetting task. Give them a call and tell them what you want the bike to do and maybe they can get you in the right direction.


Ron Dunn Jr

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  • hotwheels

Posted October 07, 2004 - 03:09 PM


Don't drill any holes in the baffle! Grind off the two small welds that hold it in, remove the two phillips head screws that hold it in, grab the small crossbar with a small hook and pull it out. Replace the two screws. Buy or build yourself a foam air cleaner and install. Drill the carb jets as follows: idle .020"(#76 drill), main .059"(#53 drill). I have two washers under the needle, one 0.040" and one 0.025". The spark plug is perfect at near sea level here in Fl. If the pipe is too loud try taking a piece of exhaust tubing and inserting it in the muffler this will take the "edge" of the exhaust note. As for drilling the holes in the slide, I have yet to do this, the bike runs well enough as it is and I need very controlable power for the sugar sand. Feel free to ask me any questions. GOOD LUCK!

  • wickedsprint

Posted October 07, 2004 - 04:08 PM


When I removed the insert on my old 650l..it did nothing except make it louder...maybe if I had rejetted it it might have..who knows.

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