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yami racer

This Place Rocks

10 posts in this topic

New to the site and just spent the last hour fishing around...I just got the '06 450F and took it for its maiden voyage on Saturday...Came across many of the main problems everyone else is having with jetting, etc. After reading everything I cannot wait to get at the carb and get out this weekend. One question I do have is can I put in the 48 pilot with out changing the Main? What is the number on stock main?

Thanks for all of the information everyone has contributed and I can't wait to become more involved here......

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... I cannot wait to get at the carb and get out this weekend. One question I do have is can I put in the 48 pilot with out changing the Main? What is the number on stock main?

Welcome.

Stock jetting is PJ 42, MJ 165.

A good combo: 48 PJ, 170 MJ, raise the needle one clip.

Leave your fuel screw at 1.5 at all times until you jetted right, it will just mess you up if you play with it too soon. Then find the sweet spot with the fuel screw.

You can only change the pilot, but please read the following I once learned from a wise tuner (thanks Daddog):

Jetting is like a high wire trapeze act with three wire walkers on the rope. And the rope is very loose.

[----------X---------------X----------------X-------------]

( cant make it curve down though just imagine that)

When one walker is too heavy the others are dragged down.

When one is too light the rope hangs funny. You want an even curve.

So you had a too light pilot in there and you were running pretty good except for the hard starting. That means you had to have an average of the right jetting.

That means the needle was a little heavy to make up for the light pilot?

Well now you want to try the 48 pilot, cause you heard how it helps hard starting.

Well, up until now the needle was pretty good, so you change the high wire walker with a heavier richer jet, and this brings the WHOLE wire down a bit and now your nice needle is off, right? And you get blurps...

So the answer is not to go back to a 45, but to now fix the BLURPS.

So we leave the 48 in there and then lighten the needle clip one clip and you see the rope raise back up and now it looks more even and the same average height again and it runs good in the accel again! see?

It is impossible to change one thing only, every adjustments changes everything a little. Just imagine the high wire walkers and youll get it.

When one wire walker gets heavier then others may have to lighten up to keep the rope at an average.

Because for every motor and every system there is a PERFECT ROPE HEIGHT and it is your job to find it.

Amazingly one pilot size is about the same change of weight for the rope as one clip size and one mainjet size.

You COULD jet by leaving the pilot stock at 42 (gag)

and the needle stock and putting the mainjet to like 180.

And it will RUN! But it will run rough.

So, keep the wire level, be an ARTIST, keep it balanced and you shall run sweeter than honey.

Happy jetting.

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That was excellent thanks for the analogy...When you say raise needle 1 clip does this mean raise the clip to lower the needle more or lower the clip to raise the needle?

Thanks again

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The latter.

Raise the needle one clip = move the clip one notch down (towards the sharp end of the needle) resulting that the needle rises one clip. :thumbsup:

:thumbsup:

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The latter.

Raise the needle one clip = move the clip one notch down (towards the sharp end of the needle) resulting that the needle rises one clip

Sureblue, the tight rope analogy appears to be saying that since you richen the pilot jet to a 48 then you may need to go leaner on the needle. If you wanted to follow the direction of of the tight rope setting, I believe you'd actually want to raise the clip a notch on the needle to go leaner (move clip away from the sharp end).

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Sureblue, the tight rope analogy appears to be saying that since you richen the pilot jet to a 48 then you may need to go leaner on the needle. If you wanted to follow the direction of of the tight rope setting, I believe you'd actually want to raise the clip a notch on the needle to go leaner (move clip away from the sharp end).

To maintain the curve you need to rejet everything. Why jet it richer on top and bottom, and then go leaner in the middle? :thumbsup:

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Sureblue

Heres the deal: Do you agree---

06 YZ450f...

Pilot 48

Main 170

Raise needle 1 clip

1.5 on the screw.

Am I even close to the right

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Sureblue

Heres the deal: Do you agree---

06 YZ450f...

Pilot 48

Main 170

Raise needle 1 clip

1.5 on the screw.

Am I even close to the right

Start with that, It depends naturally on your altitude and temps, but you should be OK finetuning with the fuel screw.

If you're lazy you can leave the needle in stock position, you'll find out what I mean when you start working on the carb...

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To maintain the curve you need to rejet everything. Why jet it richer on top and bottom, and then go leaner in the middle? :thumbsup:

I'm sorry for any confusion...I'm not stating how to jet the bike, I was only trying to clarify what was actually being stated in the tightrope analogy.

Maybe it's just me, but I have a rough time with the tightrope story. It's going to depend on how far off the jetting is from the factory and where the jetting is off at. If the bike has a big old fat main from the factory, you're just gonna change that and everything else might be fine. Where does the tightrope analogy ever come into play?

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