Hello all, I'm obviously new to this forum, need jetting info; have used 04 225 with blue pipes, 10/15 minute warm up, very light plug color. Looked at carb last night; found brass plug already drilled out, screw at 3 turns out. set screw at 4 turns out; dicn't help much Am familiar with "old" mikuni round slide, but not these newer ones. Need pilot and main jet sizes, will do z1 exhaust mod later..thanks for your help.......

The stock jets are #125 main and #40 pilot. I went up to #130 main and #42.5 pilot with fuel screw 3 turns out, but I have also done the Z1 exhaust mod. Air cleaner stock and snorkel still in place. 2 minute warmup and tan plug.

so glenn, when i bought my bran new us. 05 xt225 it has #125 main jet in it. correct ?

That is correct, pageben7456. The facory repair manual in places says that the main jet is a #130 and a #125 in other specs. It is a #125. I took mine out before I bought new jets just to be sure.

Thanks GlennF, I only want to remove and replace all that junk to get to the jets once, so will probably do both main and pilot at once, even though I may not do the pipe for a while. I plan to leave the snorkle in too, for the noise reduction factor. Also wonder about the needle; does it have several grooves, or do you have to shim it? Did you remove one of the throttle cables? I don't see the need for the extra one to close the slide. About 95% of my riding is in the dirt, but need the license plate for exploring here in Washington state, as everything is illegal with just off road tabs, except marked singletrack.

"Pops"

You will have to shim the needle if you want to change it.

As another point of reference: I live at sea level in Florida. My carb seems to run best with 2 1/2 turns out on the idle mix screw, a 42.5 pilot jet, and a 127.5 main jet; no shim on the needle. I have completed the Z1 mod, shortened my snorkle and cut holes in the side of my air box cover.

I did not shim my needle. Some like cyco have had good results doing so. To change the main and pilot, I removed the seat, tank, side covers and air scoops. I loosened the carb clamps and rotated the carb so the float bowl is pointing to the right side of the bike. You can tilt it just far enough to get the float bowl off to change your jets. I did not remove the second (or either) throttle cable.

If you shim your needle (there are no notches) as cyco did, you might have to remove the entire carb.

Actually, the midrange seems o.k, so I will probably leave the needle alone.......do you think it's possible to check the float level with the carb on the bike?

I think you will have to remove the carb as the float will be lying on its side in my method of changing the jets. I would imagine the float levels are fine unless somebody changed them. Since your bike is stock, the carb was probably never removed.

Glenn/"Pops",

I did not shim the needle. Well actually I did, and the only thing I noticed was a reduction in my fuel mileage; so I took the shim out.

By the way, I've tried to rotate the carb to change jets, but always find something in the way of getting to the screws that hold the bowl on. Each and every time I've changed the jets, I've had to remove the carb. Now that I know I have the right jets for my set-up/riding, I can get that thing in and out rather quickly.

While we're on the topic of jetting; if I ride to higher elevations, would I need to enrich or lean out the carb? I can't remember, and I can twist logic to lead to either conclusion.

Thanks

cyco,you need to go leaner for higher altitudes; by lowering the needle farther into the needle jet. If the needle has only the one groove then you need to lower it by reducing the thickness of the shim, thereby letting less fuel thru from about 1/4 to3/4 throttle, which is the area controlled mostly by the needle jet. Usually it isn't necessary to change the main or pilot jet.

Thanks "Pops"

I mostly ask because I had the bike in the mountains of North Carolina and it performed poorly. The stock needle did come with a thick plastic "shim" below the c-clip (resting in the only groove). Maybe I can use a smaller shim in its place, like the one I used to raise the needle, the next time I go up there.

Now, I've got to remember that... leaner for higher altitudes, leaner for higher altitudes, leaner for higher altitudes...

cyco,
So you noticed a decrease in power in NC. Was this after you did the jet changes? I'm going to leave my XT in NC so I will not change the jets but will just do the pilot jet to improve warm up/starting, right?
Thanks,

Vince,

I had already made the jet changes before going to NC. I am running a 42.5 pilot jet, 127.5 main jet and have the idle-mix screw out 2 1/2 turns. You will likely need to try different combinations in that area to get the best combination.