2004 YFZ 450 carb question-expert needed

[jbull70]

I need an expert to weigh in on my carb issue. First a brief background on what I have. My quad is a 2004, it has an Athena big bore kit with standard compression piston, ported and worked over head, GYTR exhaust and the air box with the mesh style lid with a foam filter and prefilter. I purchased a larger volume accelerator pump cover and installed it. While I had the carb turned, I pulled the plug to check the jetting since I just got the quad recently and it felt like the pipe was extremely hot when I was riding and it backfired quite a bit when I was letting of the throttle. Lo and behold it had a 142 jet in it along with a 42 pilot. To make the long story shorter, I purchased a 170 jet (largest they had at my local shop) and ordered a 45 pilot. Unfortunately, when I pulled the stock jet out, the whole jet extension (needle) came out. When it came out, I noticed there was a small brass fitting that the main jet screws into. The small brass fitting was then screwed into the main jet needle. No big deal, but unfortunately, when I was putting things back together, the brass fitting that holds the main jet twisted off in the needle. I think it had been overtightened previously, as I barely put any pressure on it and it snapped right off.
I went to my dealer, and the brass fitting is shown on the parts diagram for an 04, but it doesn't have a part number. If I order the jet needle, does it come with that fitting? We looked up the carb for a 2005 and it looks like they got rid of the brass fitting and use a little different style (longer?) jet, which seems like a smart idea. What are my options? Can I buy a needle and jet for the 2005 and put it in my 2004 carb? If so, what size jet do you think I should start with? I planned on a least a 170 with a 45 pilot and dropping the clip on the needle to the 4th or 5th position then starting with 2 turns out on the mixture screw. Thanks in advance for any help.
Jeff

[rt20ps]

I looked up the 04, 05, and 06 carb schematics and I don't see the difference your refering to. You need to order Yamaha part # 5JG-14947-00-00. Your starting point (45 pilot,170 main) should get you in the right direction. I would order the NCVQ needle and start with it in the middle position. You should also hard wire your accelerator pump linkage.

with your mods i would say start with a 175 and a 48 pilot and you need the ncvq needle. i sell them pm me if you need one. i can also get you jets as well. can you still screw the main jet in? if you can still screw it in you are fine. i know there was a plastic ring arounf my main jet when i first opened up the carb.