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Jetting specs for 06 crf250r with WB Aluminum Pro single system

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Hey, I installed a full Wb aluminum pro exhaust on my 06 250f last summer, however i never really played with the jetting to get it right!! anyways, just wondering what a good baseline would be for jetting @ <1000ft, @ average temp of 15C. Wb included a 160 Main jet with the kit, and said to keep the needle in the stock 3rd clip postition. However this main jet seems like it would be lean, as it would be dropped from the stock 172 that came in the bike.

The bike seems to run fairly strong, however it stumbles when you whack the throttle open quickly from dead idle, in gear and moving, without the clutch. Not sure if this is normal, can be fixed, or if it has more to do with the AP than the jetting! I'd at least like to get my jetting fairly close to where it should be before i go any further playing with the AP settings. I seem to have no delay in the squirt, and it doesn't hit the slide on the way up, but it only seems to last for a 1-2seconds. also, the squirt only goes as far as just inside the head past the boot, and then just flows into the right intake port. Any help would be greatly apreciated, and btw, it's a canadian model, with a different designation on the carb if that makes any difference to you.

Stock settings include a 172 main jet, a 40 pilot, not sure what my pilot screw is set at right now, i have to check that this afternoon. and the needle in the third position. And the only Mod to the bike would be the exhaust.

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I have been all week trying to get this issue sorted out. First i played with the pilot screw a little, and it seemed to work best at 2 or more turns out, so i knew that i needed a bigger pilot jet. A quick visit to Honda, and I was out the door with a #42 and a #45 pilot jet. Upon returning home, I decided to check the condition of the plug, it was a very light tan color, so i knew i was running a little lean. I also noticed coolant on the plug, so another trip back, and I bought both a base and Head Gasket. I replaced that, and checked my Valves, the right intake was @0.0075", so i shimmed that to 0.005". every other valve was right in the middle of the spec. I replaced the pilot jet with the #45, set the pilot screw at 1 1/2 turns, and replaced the carb. All i have to say is, what a difference, the bike starts easier, responds to throttle input off idle way better, and pulls into the mid like never before. I then decided to do the AP mod to this, and i thought there was a differnce without it, it's like a completely differnt bike right now. Theres no way i would ever spend the money on AP covers, it real is that much more responsive.

I still need to richen up my main jet a little, its' currently at a 172, stock, but i'm waiting for a 175 to arrive, it should be here on monday.

Also, it's a lot colder now than when i was riding last summer, as the average temp is probably 15 C colder than it was in september when i last rode the bike. I may have to lean it back down a step once it warms up again.

I'm going to play around a little with the needle clip over the next few days, and hopefully with that change, and the main jet, i can finally get this bike jetted to where it needs to be...... I never thought a slight change like that would actually make a difference, but it really is night and day.

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