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-   -   Jetted (https://cbrforum.com/forum/general-tech-9/jetted-149362/)

CJardine Sep 29, 2013 04:09 AM

Jetted
 
So a some may know I finally got around to getting by bike rejetted. When I got the bike back the idle was a bit low, gave it that loped cam sound (I wish and reset it to 1250 RPM). They gave me a dyno sheet with two runs on it and at the time I honestly thought nothing of it. Now looking back on it I don't know if the two runs are a before and after /both after or what, nor did I ask the guy any questions as he had taken his lunch break and to top it off I was busy all day so I never actually watched him work. So now I'm here with a piece of paper with squiggly lines on it and not much knowledge about it other that it was run on an eddy current dyno and the figures have been corrected to SAE. Should I go back and ask for the file? Would they have saved the file and be willing to give it to me? How does it look, I'm a seat of the pants kinda guy - I'm not worried about the numbers more interested in how it rides, that's faster. Is there anything I need to be worried about and are they trying to pull the wool over my eyes? And lastly is this worth flashing in my friends faces :icon_angel: Or hiding in a deep hole. :icon_emm:

Here is a stock bike courtesy of sport rider and dynobike
http://image.sportrider.com/f/182641...nda_torque.jpg

http://dynobike.com/gallery/technica...dyno_chart.jpg

Here is my bike, I will scan it and replace with a better copy.
See Below

CJardine Oct 1, 2013 03:28 PM

1 Attachment(s)
Here, this should be a bit easier to read, hope someone can get back to me.

Attachment 30977

Conrice Oct 1, 2013 04:26 PM

Uhh, I'll answer later in more depth.


But maybe an air needle adjustment is needed or a different secondary jet or something to fix that midrange at 5k rpms. It's WAY TOO rich right there. If you ride there often, I would work on fixing that. It'll hurt your MPG, and the it's a lot of fuel. It could help your power curve a little bit too if you fixed it to make it more smooth.


Maybe call them and ask for their advice on how to fix that slightly?

CJardine Oct 1, 2013 04:56 PM

Thanks and yea it took them a week to get me this one runfile instead of the printed sheets of paper. When I saw the A/F :icon_emm:. Sent an email to Marc at Factory Pro too, lets see what he has to say about this.

Edit 2: Upon further review based on the notes supplied, they put in main jets #132 out/#132 in, Honda uses #132 out/#135 in,FP recommends that with my bike (BMC race, Full System, and ign. adv.) that I should be in the ballpark of #138 out/#140 in. and richen the mains 2-3 and needle 1 above base settings and that's with 87 not the 91 that I use. What would cause them to put smaller mains? I understand that its on the rich side all the way up to 10.5 rpm? Also Don't I want to be aiming more for an AFR around 14.7? Guess I gotta call them again, I'm sure they are already tired of seeing my number pop up on their speed dial.

LDH Oct 1, 2013 08:14 PM

Smaller mains are used with skinnier needles on some jet kits, but there is so much more to this than I can type out in detail right now and there is a big difference between full throttle runs and cruising at 5000rpm with virtually no throttle where it shows rich. Give me a call bro...

CJardine Oct 1, 2013 08:37 PM

Yup will in the morning for sure. Thanks.

Conrice Oct 1, 2013 09:00 PM

Try lowering the needle height. It leans out to a good a/f when the rpms go up - so I think the main jet size is right. But something is happening to where you're not getting enough air in that range. I've read a few other carb tuning sites - and most of them say either secondary jet or needle clip position. Lowering the needle/raising the clip leans out the mix in the midrange.


CV Carb Tuning Procedures

Needle clip position - explained? (reply #4)



The factory pro website gives you good measures for not using a dyno, so I'd go with that.

CJardine Oct 1, 2013 09:08 PM

Yea I've poured over their website and have thier cv carb tuning guide sitting in front of me.

Ls1Mx5 Oct 1, 2013 10:58 PM

Yea try raising the needle clip by one position like what the others are saying. Should lean out that area where it drops down to what looks like 10.5:1 (wayy to rich IMO). Good numbers though


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