XR650L Snorkel removal and jetting

9 replies to this topic
  • Xr650LMartin

Posted September 14, 2004 - 06:27 AM


Anyone can help me please? I just bought a 650L and I want the extra power in there!! I wanna remove snorkel and rejet! Smog kit already dumped! I never opened a carb in my live so is there any tips on how to proceed? I live at sea level and I wanna use Keihin 55 and 158 jets,is that ok? Thanks a lot :thumbsup: :lol: :awww: :devil:

  • XR650L_Dave

Posted September 14, 2004 - 09:13 AM


Gonna make it easy on myself and dump in a response I posted recently.

Drill the slide, shim the needle, remove the snorkel, use a good air-filter, grind the tab, rejet.
The set-up:

You drill the holes in the slide that are off-center to 5/32 of an inch. There are 3 holes, one in the middle for the needle and 2 off to the side- drill the 2 not in the center.

THE NEEDLE: When you pull the slide, the needle is held into the bottom of the slide by a little yellow widget that you press down on and turn a little with a screwdriver or an 8mm socket. When you remove that, the needle comes right out. Notice that the needle sits in a small recessed section, a little well. Find a small washer that meets the following
1) is about 20-30 thousands of an inch thick.
2) fits fairly snugly over the needle at the thickest part at the top.
3) has the same outside diameter as the top of the needle.
You just put the needle through the washer like you would a washer on a bolt so that the needle will be raised up out of the slide by the thickness of the washer. Some have found washers like this in a kit at radio shack. I found one that I had to make a little smaller on the outside diameter in my "supplies".

If you do this, remove the snorkel, and grind off the tab on the bowl that keeps you from spinning the low-speed mixture screw around, and put in a good air filter, you'll wonder how you managed to ride the bike without these mods. If the mixture screw is out more than 2-3/4 turns, you need to go up on the pilot jet.

The suggestion to replace the screws on the carb with allen heads is an excellent one as well. I replaced the 4 bowl screws, the 4 screws in the top, and the 2 that hold on the throttle cover.

The slide gets raised when vacuum is applied at the bottom of the slide, and the holes are how the air leaves the area above the slide. Hence, the bigger the holes the more faster the air can leave.

I'm running stock exhaust, K&N filter, and run a 55 pilot and 158 main (both keihin jets from Baja Designs), and this setup is rich enough to run with the baffle out. Note that there is a 55S short pilot jet, and the 55 regular pilot jet will work but you have to trim the slosh baffle in the bowl a little, as it can move a little and partially cover the pilot jet.


  • DesertWill

Posted September 14, 2004 - 11:20 AM


I just got my XRL too...removed the snorkel and re-jetted. After speaking with the guys at XRs Only, they suggested I try the 55 & 158 jets w/o the shim first. My bike runs much better than before and I'm getting around 52mpg.

The hardest part about changing the jets is getting the carburetor rotated so you can get the float bowl off. I removed the rear brake fluid reservoir and rotated the bottom of the carburetor that way. When the float bowl is taken off be careful that you don't loose the pin in the float. It likes to slide out. You can remove and replace the jets with a screw driver. You'll see them in the bottom of the carburetor.

Also, I installed a K&N air cleaner.

  • Xr650LMartin

Posted September 14, 2004 - 02:42 PM


Thanks a lot guys! I plan on doin it this weekend! I should be ok with your tips!! :thumbsup: :devil:

  • Winter_Hawk

Posted September 15, 2004 - 04:11 PM


Hey everyone - first post here. :thumbsup: I'm a rider from CT, currently living in Prescott AZ. All I can say is wow; this is all some really great info! I just picked up my L two nights ago and I am hooked! It has a White Bros E series can on it and it sounds great! This is a great forum too, and I am excited to be a part of it.

So far, I am curious about how to smooth her out and get some better performance. It's fast as is, but lacks low-end throttle response. It seems to be right on with a little choke, but I'm afraid that might not be good for it. Can anybody tell me what this might be? Rich? Lean? I am not sure what's going on, but want to have optimal performance for sure. I am in CT right now, but will be in the mountains of AZ after this week and am looking for suggestions as to jets. If anybody could lend me some advice, that'd be great!

It's an 03, bone stock except the E Series can and I'll be at 5000 feet. Thank you guys in advance for all your help!


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  • XR650L_Dave

Posted September 16, 2004 - 11:15 AM


You're in CT at the moment? I'm below Hartford, in Berlin.
If the jetting is stock, its lean for sure!
The standard mods are all about boosting the low-end and the throttle response. The altitude will prob. cancel out the richer jetting the pipe requires, so 55-158 will probably turn the trick.

If you're near Berlin, you can check mine out. Send me an email.

dstephen67 at earthlink dot net
dcloss at c-cor dot net

  • Winter_Hawk

Posted September 16, 2004 - 07:51 PM


Thanks for the reply :devil:

The standard mods are all about boosting the low-end and the throttle response.

heh heh, thweet :awww:

The altitude will prob. cancel out the richer jetting the pipe requires, so 55-158 will probably turn the trick.

So, with the pipe at 5000 feet, I should drill the slide, shim the needle, remove the snorkel and use a 55p158m set up and go from there? Sounds good to me! I can't wait to be home and have this thing out there...

If you're near Berlin, you can check mine out. Send me an email.

dstephen67 at earthlink dot net
dcloss at c-cor dot net

Thanks for the offer, but unfortunately...no time. I'm in Wilton, prolly an hour away and I really don't even have one of those to spare right now. (so why am I typing? Oh yeah! I SHOULD be sleeping :thumbsup: Heh, I find this site and buy this bike AS I'm finishing the job and headed home. That'll leave me with lots to ponder while braving the monotony of the Interstates for 3700 miles.

YGM XR650L_Dave

  • XR650L_Dave

Posted September 17, 2004 - 08:46 AM


XR650LMartin just sent me a PM on his post-mod test ride.
It started with "WOW!"


  • Xr650LMartin

Posted September 17, 2004 - 08:57 AM


The mods I 've done kick ass!!!! The throttle response is awesome! Instead of coughing in 2nd gear at low speeds the dirt flies!!! :cry: :cry: :cry: :cry:

  • Winter_Hawk

Posted September 17, 2004 - 06:22 PM


Oh boy! I can't wait. You should see my smile right now. :cry:

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