what jet is it?

[slightlybent47]

I put what I thought was a stock 450 carb on my ex and it ran good right off the bat.
Thinking it had stock jets in it and stock was 118 main, I picked up a 120 and a 125 main jet.
Then after taking off the old jet I notest it had a 188 RD on the old jet. So what brand is a RD and what is a 188RD convert to? That cant be a stock jet.


Thanks

[GPracer2500]

RD = RD Precision.

EBC Brakes owns a company called A-BAX Engineering which took over RD Precision a couple years ago. So, EBC's newest jets are labeled "AB" but you'll still see some EBC distributed jets labeled "RD". RD or AB: they're replicas of factory Keihin jets. No "conversion" is needed.

The 04/05 carb's HRC jetting uses a 185 main. The 118 is only appropriate for a showroom stock 450r without the HRC airbox and exhaust mods. Regardless, if you're putting the carb on a 400ex the stock jetting for a 450r isn't relevant.

[slightlybent47]

Ok thanks:
I wondered why it ran so good right away. I think I'm still a little lean so I'll take the jets back and see if i can exchange them.

One other question; the jets I got at the dealer have stare next to the number. Who makes that?

[GPracer2500]

That star is a stylized "K". They're made by Keihin.

[slightlybent47]

Ok thank you very much!!!

[tri5ron]

Originally posted by slightlybent47
Ok thanks: I think I'm still a little lean so I'll take the jets back and see if i can exchange them.
I could be wrong here,
but 188 and still lean dosen't sound right to me. are you sure you don't have an air leak somewhere?

[slightlybent47]

I'm not stock, 416 - 12:1 stage 2 cam P&P, head pipe ported, WB slip on, 450 carb with the air cover off.

[atv fan 28]

Originally posted by tri5ron
I could be wrong here,
but 188 and still lean dosen't sound right to me. are you sure you don't have an air leak somewhere? X 2!!

[slightlybent47]

It starts right up, almost instantly and idles perfect. Runs real good all the way through the throttle range. Doesn’t spit or sputter during acceleration or deceleration. When I pulled the plug it looked a little whiter then it did with the stock carb witch had a 174 main in it on the same build.

I think i'm real close to where it needs to be.

I'm also useing U4.2

[atv fan 28]

did you do a plug chop? 174 and 188 is a big difference!

[slightlybent47]

Originally posted by atv fan 28
did you do a plug chop?

Yep


http://i37.tinypic.com/feqjwo.jpg

[MtnEX]

Originally posted by GPracer2500
RD = RD Precision.

EBC Brakes owns a company called A-BAX Engineering which took over RD Precision a couple years ago. So, EBC's newest jets are labeled "AB" but you'll still see some EBC distributed jets labeled "RD". RD or AB: they're replicas of factory Keihin jets. No "conversion" is needed.

Piggy-Back question for YOU...


How "good" of a Keihin "REPLICA" are they do you think?


The guy who did my stuff used an RD Precision main jet in my 400EX carb.

My carb is still not right, so I am ordering some Keihin jets of various sizes.

If you think the RD is the same, there are sizes I can avoid buying for nothing.

[GPracer2500]

Originally posted by MtnEX
How "good" of a Keihin "REPLICA" are they do you think?....

I can only guess that they're likely to flow the same as an equivalent Keihin. Although a jet is a precision machined piece, making them isn't exactly rocket science. I'd say chances are good there is no difference.


Nonetheless, in my personal jet supply I've got the factory Keihins separated from the aftermarkets. I'll only use the aftermarkets if I'm missing a size or for when I'm using my jets to help friends. I reserve the Keihins for my personal use because I trust Keihin and feel better using them vs. an aftermarket jet.