Same Keihin jets fit '05 and '06?

I have a JD jet kit for '05s and someone told me that the needles won't work on an '06 but I was wondering if the main and pilot jets changed as well? I just got a '06 YZ450 and still have a bunch different size jets from my '04 WR. Can I use them on that or do I need to get specific ones to fit the '06?

You can use the same jets just do a search here and make sure you put the right sizes in for optimum performance.:thumbsup:

All kehein FCR jets are the same. The needles might apear to fit, but they may be shaped different. If I were you I would sell the JD needles, and instructions on ebay.

I have an 06 450 and run a 45 pilot 168 main currently. I just picked up an NFLR needle (factory needle for an 07) and a 170 main. This should help out alot. I might also go up to a 48 pilot.

I think for winter a 48 pilot 170 main

and for summer a 45 pilot and 168 main should work great.:thumbsup:

All kehein FCR jets are the same. The needles might apear to fit, but they may be shaped different. If I were you I would sell the JD needles, and instructions on ebay.

I have an 06 450 and run a 45 pilot 168 main currently. I just picked up an NFLR needle (factory needle for an 07) and a 170 main. This should help out alot. I might also go up to a 48 pilot.

I think for winter a 48 pilot 170 main

and for summer a 45 pilot and 168 main should work great.:thumbsup:

Are you at sea level ranger? That's exactly what I'm thinking when I pick up my YZ on the 2nd of January. 170 main, 48 pilot with the NFLR needle. Talking to burned, he thinks I could run this all year here in Mazatlan. It doesn't get much over 90 here in the summer but is way humid (hence, I surf more and ride a little less).

BTW- can someone explain to me how humidity effects jetting?

Are you at sea level ranger? That's exactly what I'm thinking when I pick up my YZ on the 2nd of January. 170 main, 48 pilot with the NFLR needle. Talking to burned, he thinks I could run this all year here in Mazatlan. It doesn't get much over 90 here in the summer but is way humid (hence, I surf more and ride a little less).

BTW- can someone explain to me how humidity effects jetting?

I ride at about 2000', but live at 500' I can ride around my house and the bike feels great, and when I ride desert it feels great also. I'm switching to the 170 main forsure because I get some hesitation on my top end. My low end is good with a 45 but a 48 is great. I think you could ride all year with the 170, 48 especially at sea level, but if you notice a little decrease in power I'd switch to a 168, 45. As far as humidity I have no idea how it effects jetting, but I do think it would help cool the charge(cause the gas to be more dense) which is a good thing.

Humidity occupies space within the air mass, and in doing so, displaces oxygen from the air, so higher humidity requires leaner jetting, just as do higher temps and altitude.

Grayracer, how much difference does humidity make? Is there a recommendation chart like there is for temperature and altitude? Do you think a 48 170 will work all year or will I have to drop to a 168 when the temperature hits 90 and the humidity is high as well? To be honest, I try to only ride in the morning when it's cooler (maybe 80) 'cuz I'm soaking wet if I ride at mid day.

I'm just curious if 20% to 80% humidity equates to a jet size and also which jets.

I don't think it affects things as much as temp and altitude, except at the extremes, but then where I am the humidity usually doesn't swing much, and it conveniently runs opposite the altitudes I ride at somewhat, so I more or less ignore it.

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