Stock 2002 XR50 Jetting

I've got a stock 2002 XR50 and it is running way too rich. I have a few questions.

1. What is the stock main? Mine came with a 58

2. How many turns out should the air fuel mixture screw be? Mine came with only 1/2 turn out.

3. Anyone jet theirs for 6,000 feet and above? I live in Colorado and my guess is that the dealer didn't rejet the bike when I picked it up.

Thanks for any help in advance.


Is it safe to assume that nobody on this site knows how to jet a 2002 XR50 in Colorado?

I did find out that the stock main is a 58.

Once I get it straightened out, I'll post my findings.


I would first try the needle with the clip in the top position and the stock 58 main and see if that helps. Play with the air screw to see if you can clean it up. If that does not work go with a 56 main as you are at higher altitude. I would then place the needle clip at the bottom slot and repeat the process threw all the needle slots and using the air screw to clean it up. You can also try a hotter plug. I use to live in Lake Tahoe and would have to mess with my jetting in my bikes so I know how fusterating it can be. Good luck and hope this helps.


Atom RoTTeN

Thanks for responding. I saw that people had read my post but didn't get any answers. I didn't even get ripped on or anything.

I called the Honda shop last week and they don't sell a main smaller than a 58. I sent an e-mail to BBR and haven't heard back yet.

I turned the air screw out 1 1/2 turns (was 1/2 turn) and it seems to start easier now. I'll start messing with the needle as well. It came with the clip on the second from the top so I'll raise it and see how that goes.

I know it is primarily a slow speed problem right now. The reason I say this is because I have the throttle limiting screw in so my son can ride it with training wheels. I need to remove the screw and ride it hard to make sure I need to reduce the main. I am fairly confident however, that at this altitude, the sea level main is to rich.


Since this is for your son and your not even at the main jet running area.. that is kinda mute point really... Since it was running rich on 1/2 (that 1/2 turn is usally around where you want to be with a open pod aftermarket filter) We woudl say maybe lean the pilot (just kidding it does not have one) That is pretty much limiting factor here. Actually try to play with the air screw a bit more 1 1/2 to 2 would work fine.. a 70 carb with pilot jet may help you out like you don't know... Call if we can help you out!! 1-530-268-7368 (we will even give you a colarado discount!! :)

I realize that most of the riding conditions that this bike will encounter for a while are not utilizing the main. I was running it without the throttle screw and "on" the main when I checked the plug and it was really rich.

Now that it's being run at 1/2 throttle or less, it's even worse so I need to mess with the air screw as well. I'm going to experiment a little with the screw and see if I can lean it out just a little down low. I'm also going to drop the needle by putting the clip in the top notch.

I found out some interesting information as I've been searching. 58 main is stock and as small as you can get. I also realized that it didn't have a pilot jet.

If I can't get it lean enough with the air screw, I'll probably contact you for a pod filter. It looks like a real pain to clean the stock unit. What about a hotter plug?



Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now