Exhaust on 2007 XR650L

Hey Guys......If you remove the silencer off the tip of the exhaust on the XR650L and thats all you do to it....will it need to be jetted?

Hey Guys......If you remove the silencer off the tip of the exhaust on the XR650L and thats all you do to it....will it need to be jetted?

Look at it this way, if it is a new, factory-spec L, then it needs to be re-jetted.

Once jetted (I recommend Dave's Mods---he has very good instructions), if you mean the insert/baffle, then that shouldn't affect the backpressure too much, so you can run with it in or out with the same jetting.

thannks!!!.....have any ideas on breaking that weld?

thannks!!!.....have any ideas on breaking that weld?

I used my Dremel tool with a grinding bit. Hit the bare metal areas with some Krylon afterwards.

where can i find Daves mods for rejetting my XR650L?....web address?....

This all located at 4jokes I mean www.4strokes.com


There's a photo here somewhere of the slide, gallery? tech section?

You drill the holes indicated 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.

Remove 2 allen head screws (using a 5mm allen wrench) from both metal tubing mounts on the front of the crankcase (you must remove both mounts at the same time because the metal tubes are welded together). Don't lose the screws because you can re-use them when installing the block off plates.

Remove 2 nuts from the smog pump assembly to reveal the mounting bracket bolts that are located underneath. Remove the mounting bracket bolts and the mounting bracket. Put the mounting bracket and smog pump assembly back together so you can heave the whole thing into the lake in a single motion.

Remove the left-side body panel to allow more room to work. Remove the evaporation canister (the black thing that looks like a Toro sprinkler head located near the fuel shutoff petcock) by lifting the rubber mount straight up and off the mounting tab. You'll learn the fine art of "finagaling" when you perform this step. Move the spring clamps out of the way and then remove the hose(s) from each of the nipples on the evaporation canister.

Pull all the rubber hoses off the plastic "T" fitting and completely remove the short hose that runs from the top of the crankcase located underneath the carburetor (its too short to be re-used). Cut the longest rubber hose that runs from the bottom of the airbox to the smog pump assembly (approximately in half) and put the open end into the botttom side of the "T" fitting. Push the hose that runs from the top of the airbox into the top side of the "T" fitting. NOTE: You'll notice that this hose is slightly smaller in diameter than the others, but it can still be pushed onto the "T" fitting. Salvage the other part of the longest hose by removing the hose clamp from the smog pump assembly. Use this chunk of hose between the fitting on the top of the crankcase and the middle part of the plastic "T" fitting.

Pull the small tube off the nipple located on the back side of the smog pump assembly (approximately 1/4" in diameter). Follow this hose up to the top, left side of the carburetor. Remove this end from the nipple on the carburetor. Follow the hose further up to the "T" fitting, over and behind the carburetor to the right side. Remove this end from the nipple on the carburetor. Now that you have the entire tube removed, salvage the medium length piece of tubing from what you are holding in your hand. Route this chunk of tubing from the nipple on the right side of the carburetor up and over the front side of the carburetor to the nipple on the left side. NOTE: There's more room to run the hose in front of the carburetor. It appears that it would be more difficult to route the hose up and behind the carb again.

Since I was too cheap to part with the twenty bucks for the IMS block-off kit, I fabricated my own block-off plates (to cover the open holes on the front of the crankcase). I used a flat piece of steel, approximately 1/8" thick for this purpose. First, I created a template using gasket material and an X-acto knife. Once I had the general shape, I transferred it onto the steel. With lots of sweat and sheer determination, I made the block-off plates using a hacksaw, file, grinder and heavy-duty sandpaper. You can use anything that will take metal off, if you have enough time. At this point, I began to realize the twenty bucks might have been money well spent. In any case, I made one plate and then used it as the template for the second plate (just reverse it for the other side). I secured the plates using the same allen head screws that were removed first. NOTE: I didn't use a gasket underneath the block-off plate but I'm considering doing that to prevent leakage.


where can i find Daves mods for rejetting my XR650L?....web address?....

In the video section of thumpertalk.

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