Having problems uncorking...NEED HELP!!! XR650L

I bought the ($51.95) Dyno Jet Carb Kit featured on the Baja Designs website from my local Honda Dealer. I wanted them to jet the carb for me because I didn't feel comfortable drilling holes in it for the jets or what-what-not. I also had them put on the Cobra Exhaust for me.

(now here comes the stress!!!!)

They dealer called me when they had the bike done. However they said they broke my air-mixture screw on my carb. :) !!! They said they didn't get a chance to dial it in, but they said the bike is drivable. I fired it up and loved the exhaust sound. I took it for a test-drive and I thought I would never reach 55mph! The bike was drowning big time, not to mention spit'in and sputering. The bike idled fine and I could crack the throttle in neutral and it sounded somewhat normal. However, when you go to cruise it down the road the bike wants to die when you go to give it some juice.

I took the bike back and told the mechanic that the bike was drowning and he gave the the tools neccessary to drill the rivets out and remove the snorkle. I took it for another run and the power was somewhat decent 70-75mph. The power was not too awful bad between low and low mid range RPM, but I have no top end what so ever. The bike, before mods, had an awesome first gear power-wheelie. Now my power wheelie is about 2inches, which will not get the job done.

I have a foam air filter that is pretty decent in size. I was wondering if that stupid air-mixture srew is causing me all these problems. The part should be in on Monday, and the dealer said they needed to drill the other out, tap it, and put the new in. The stock jets on the bike were size 150. The instruction sheet said to install the 165 jets if you run an aftermarket exhaust, and use the 160 jets if you run the stock exhaust. The instructions also had a note stating that no mods to the airbox are required. The dealer installed the 165's. He also mentioned someithing about the needle setting. The instruction book wanted the needle placed 3 down from the top (no idea what that means). I am not sure what is causing me all this grief.

Would someone please give me some helpful intuition on this sore subject. The dealer doesn't have any advise, they ran out of ideas except for the mixture srew not being set, but they said that won't make that much difference. My XR is running like crap, and I paid too much money to just accept it. Please Help!


I do not know why you are having a problem with your top end. It sounds to me like that dealership is pretty incompetent. I did the BD mods to my friends XR650L and I did remove the snorkel, installed the same jets, enlarged the holes in the vacuum diaphragm and raised the needle. However, you stated that the instructions mentioned that you had to move the needle 3 positions from the top. The needle on a XR650”L” does not have different clip positions. The way the needle is raised on the L is by placing a shim (washer) on the needle where it seats in the vacuum diaphragm. This raises the needle and gives you more fuel in the mid range. The pilot screw is responsible for idle to ¼ throttle. If you are having top end pains, I would check the main jet. The main is responsible from ¾ to full open throttle. However, if you have a pipe and the snorkel removed from the air box and are not very high as far as altitude goes (Ohio), I would not think that the main jet would be the problem if it is a 165. If they did not drill the holes out larger in the vacuum diaphragm, this may cause a slight problem. The BD kit should have come with the correct drill size for that operation.

The fact that you stated that the directions said to raise the needle to the 3rd position has me concerned. This would be correct for the 650”R” not the L.


XRider, you are a life saver (bike saver)!!! I called the "mechanic" back and gave him your insight. He said the kit he put on did not have a drill bit to inlarge the diaphram holes. He said the new needle he put had several adjustments, and thats why he put it 3 positions from the top. It appears that they ordered the wrong kit, or the wrong kit was packed. The dealer is going to figure out if they can order the right needle and drill bit, or order the correct kit and install it free of charge. Thanks again XRider!


No problem. I am glad that your problem is resolved. There is nothing worse than spending money to improve something and have end worse than you started.

It sounded like they gave you a 650R hop up kit. You are lucky that I have that bike, installed that kit and I also just installed the kit with the drill bit on my friends 650L.

Good Luck,


Oh by the way, you better have just get the kit. It has good instructions and it sounds like your "mechanic" is going to need them

Here is another twist and more stress to the situation. The dealer called Dyno Jet and they said they have the correct kit installed. I told them I wanted them to take the kit out and I would order the correct kit from Baja Designs. They still insisted that they had the correct kit. They said that Dyno Jet gave them some troubleshooting tips to correct my problem (put snorkle back on, try 160 jet, tape air filter, ect.).

I flipped out and gave Baja Designs a call. BD said that the old Dyno Jet kit was replaced with this new one about two weeks ago. BD said that they have had good reviews from it so far. The new kit does not require diaphram drilling and comes with an adjustable needle. BD said that the broken fuel mixture screw may be the problem. He said the carb on the XRL is very sensitive.

I am now at the mercy of the Honda dealer and I am putting all my cards, as far as poor performance, on the air/fuel mixture screw. I will let you know how the new kit works. Let me know if you have anymore ideas or tips.


Toast, I can walk you through any details if you decide to do the job yourself...I'd be nervous with your dealer botching up a basic install like that, especially if they sold you the carb. kit!!

My friend had the kit that I installed on his bike for quite some time before I installed it. He purchased it from BD. I don’t know if it is the old kit or not. It must be if the new one came out two weeks ago. However, his bike does run great. BTW.....He is running a Yosh pipe.


Geez...what a mess. The best way to modify is one step at a time. It makes it much easier to troubleshoot any problem. It's not impossible that it is the pilot screw. But they would have to have it grossly mis-adjusted. I broke mine off because I stupidly attempted to trim the tab on the screw instead of grinding the stop on the carb. My next guess would be needle clip position. The dyno-jet kit gives you an adjustable needle, and some L's have been known to run best in the stock setting (1st groove, needle all the way down). I got my pilot screw out with a set of sharp picks. could also turn it fairly easily with a pick, till I got a new screw. Lastly, some aftermarket pipes have been known to cause a decrease in power, either at top or bottom end. I'd try the stock exhaust and see how it runs. Every bike is a little different. My bike ran better with the snorkel in, despite rejetting.

The air mixture screw finally came in! The dealer took the carb off, replaced the screw, took the 165 jet off and put in the 160, and instead of having the needle adjusted 3 down from the top, they put it 4 down from the top. They put the carb and snorkle back on and took it for a buzz. He came back and took the snorkle back off. I took it for a test ride, and it rode pretty darn good. I can bring the front tire off the ground a lot easier now. I have my power-wheelie back! The bike runs pretty good. I am still wondering if the 165 jet would have worked with the broken screw replaced. All in all, I gained an estimated 2-5 hp. with the jet kit and exhaust. Not too bad for a bike.

Remember, Dyno Jet changed their jet kit for the L. It is the same part number as the old kit, just different goodys. I am running my bike with the 160 jet, needle set 4 positions down from the top, and snorkle removed.

Thanks to everyone (xrider, Jim, and 85361) who has helped me out with these problems. I don't know what I would have done with out you fellas.


Could someone please inform us of what size this "magic" drill bit is that come in the kits? I have read a lot of posts, and this isn't mentioned. I would rather just use a drill I already have, and then custom tune it with individual jets.

I figured out a trick to remove the alloy cap on the pilot screw. Heat it with a torch. But, if you get the little spring hot, you will ruin it. I held the section with the spring under water, and heated the alloy tip with a propane torch. It's melting point is lower than that of the brass screw, and I melted the cap right off. Worked great.

In the original BD jet kit, the drill bit was 5/32. The Dynojet doesn't use a drill bit, it uses a weaker slide spring. In my opinion, after trying both, the effect is minimal. The jetting makes a much bigger difference than the slide modificatin.

I put a .023" washer under the stock needle, which seemed to help a bit, but this richeded the idle circuit up significantly. Now I have to run my pilot screw almost all the way in. Is there a replacement needle that is stock length but a different diam. or profile?

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