richer needle


8 replies to this topic
  • package

Posted February 18, 2008 - 02:32 PM

#1

I was hoping somebody out there could help me. I have a 2007 yz 450f and I just rebuilt my motor. I put a weisco high compression piston and stage 1 hot cams in it. I also put on a full pro circuit ti-4 pipe. I put the jets in that pc recomended, but my plug was as white as a tee shirt. They recomended amoung other things a 165 main jet. I kept trying main jets until I reached a 195 main jet, and raised my needle 2 positions, but still my plug is white as can be. I know I need to get a richer needle but I dont know which one. Please help!!

  • grayracer513

Posted February 18, 2008 - 02:54 PM

#2

First off, you can't read a plug to gauge your jetting unless you use leaded fuel. Second, the only valid method of reading plugs is a full throttle run, chop the throttle, kill the engine and coast to a stop.

If you are between 1000 to 3000 feet, I would say that a 165 would be correct most of the time. I doubt that you need any different needle than the NFLR that came with the bike.

  • package

Posted February 18, 2008 - 04:20 PM

#3

I did do the full throttle test and the plug was white. I'd like to get a second opinion on the plug not needing to be a tan color.

  • todds924

Posted February 18, 2008 - 04:39 PM

#4

First off, you can't read a plug to gauge your jetting unless you use leaded fuel. Second, the only valid method of reading plugs is a full throttle run, chop the throttle, kill the engine and coast to a stop.

If you are between 1000 to 3000 feet, I would say that a 165 would be correct most of the time. I doubt that you need any different needle than the NFLR that came with the bike.


Gray, Pro Circuit recommends an NFPP needle for that year with there pipe. Also a 42 pilot and 50 leak jet with a 165 main.

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  • todds924

Posted February 18, 2008 - 04:42 PM

#5

I was hoping somebody out there could help me. I have a 2007 yz 450f and I just rebuilt my motor. I put a weisco high compression piston and stage 1 hot cams in it. I also put on a full pro circuit ti-4 pipe. I put the jets in that pc recomended, but my plug was as white as a tee shirt. They recomended amoung other things a 165 main jet. I kept trying main jets until I reached a 195 main jet, and raised my needle 2 positions, but still my plug is white as can be. I know I need to get a richer needle but I dont know which one. Please help!!


You say you put the jets in that they recommend but all i heard you mention was the main jet change. Pro circuit recommends changing every jet pretty much in that carburetor for that year. NFPP needle/42 pilot/165main/50 leak....fuel screw 2 out.

  • package

Posted February 18, 2008 - 06:03 PM

#6

I changed every jet just like they spec, but thier rep didnt say anything about the needle. I'm going to try that next. Anybody else do anything similar? how did it work?

  • todds924

Posted February 19, 2008 - 05:05 PM

#7

I changed every jet just like they spec, but thier rep didnt say anything about the needle. I'm going to try that next. Anybody else do anything similar? how did it work?


If you changed all the jets like they Spec., all you need to do is change to the NFPP needle like they spec.... Let us know how it works!:applause:

  • ifix

Posted March 07, 2008 - 01:26 PM

#8

I changed every jet just like they spec, but thier rep didnt say anything about the needle. I'm going to try that next. Anybody else do anything similar? how did it work?


Hi,
one factory engineer told me:
NFLR needle on 3rd;
min jet: 45
max jet: 172
screw: 1.3/4 out
bye...

  • srfdwg2

Posted March 07, 2008 - 01:37 PM

#9

I have the same pipe,I went with a 47 pilot 165 main,adjustable r&D pump cover set at 50.thing runs awesome.Also "ZIP_TY carb mod".





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